In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar perce...In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.展开更多
The development of ZnO-based composites with high charge separation and effective inhibition of toxic by-products is admirable for effective photocatalysis of nitrogen oxides(NO_(x))oxidation.In this study,carbon quan...The development of ZnO-based composites with high charge separation and effective inhibition of toxic by-products is admirable for effective photocatalysis of nitrogen oxides(NO_(x))oxidation.In this study,carbon quan-tum dots(CQDs)/ZnO hollow microspheres,synthesized through a rapid microwave-assisted method,achievedover a 30-fold higher NO_(x) removal efficiency compared to ZnO,with complete inhibition of NO_(2) by-products andgood durability.The enhanced photocatalytic activity was ascribed to the unique role of CQDs,as revealed byin-situ photoelectric techniques.Results demonstrated that the electron directional migration from ZnO to CQDsat the composite interface accounts for the enhanced charge separation.Active free radicals for NO_(x) oxidationwere identified,and in-situ diffuse reflectance infrared Fourier transform spectroscopy analysis elucidated theconversion pathways of NO_(x) oxidation under visible light irradiation.This work sheds light on the mechanismsof electron transfer and charge separation at the composite interface,offering guidance for designing superiorZnO-based photocatalysts for complete NO_(x) removal.展开更多
The photoconversion of CO_(2) to carbon-containing fuels,splitting water into H_(2),selective organic synthesis,reduction of N_(2) to NH3,and hazardous organic contaminant degradation represent feasible schemes for so...The photoconversion of CO_(2) to carbon-containing fuels,splitting water into H_(2),selective organic synthesis,reduction of N_(2) to NH3,and hazardous organic contaminant degradation represent feasible schemes for solving environmental and energy issues.In 1972,TiO_(2) was applied for decomposing water into H_(2) and O_(2) via photocatalysis.Owing to its the low visible-light utilization,fast charge recombination,and high energy barrier for water oxidation,overall photocatalytic water-splitting efficiency is extremely low.Because H_(2) is more economically valuable than O_(2),sacrificial agent-assisted photocatalytic H_(2) evolution has been extensively investigated.Because the sacrificial agent can quickly consume photoexcited holes and effectively reduce the water oxidation energy barrier,photocatalytic H_(2) evolution efficiency can be increased by 3-4 orders of magnitude compared to photocatalytic water splitting.However,the overuse of sacrificial agents contributes to wasted photoexcited holes and expensive processes,while presenting potential environmental issues.Recently,overall charge utilization and improved redox efficiency have been achieved by coupling photocatalytic reduction with oxidation reactions.Moreover,overall charge utilization can boost charge separation and increase photocatalyst durability.However,the photocatalytic mechanism of the overall redox reactions remains unclear,owing to the complex reaction processes and design difficulties.Herein,the basic principles of photocatalysis are discussed from the perspective of light harvesting,photoexcited charge separation,thermodynamics,and redox reaction kinetics.Photocatalytic redox reactions,including overall water photodecomposition,photocatalytic H_(2) evolution coupled with organic oxidation,photocatalytic CO_(2) reduction coupled with organic oxidation,photocatalytic H_(2)O_(2) production coupled with organic oxidation,photocatalytic N_(2) reduction coupled with N_(2) oxidation,and photocatalytic organic reduction coupled with organic oxidation,can be systematically classified according to the coupling of photocatalytic oxidation reactions with photocatalytic reduction reactions.Subsequently,the design of photocatalytic redox reactions is considered in terms of the modulation of photocatalyst materials,reaction conditions,and diversity of reactants and products.In addition,the vital role of density functional theory(DFT)calculations for unveiling photoexcited charge transfer,rate-determining steps,and redox reaction barriers are discussed in the context of the work function,electron density difference,Bader charge,and variation in the intermediate adsorption free energy profiles.The activity and mechanism of various photocatalytic redox reactions were elaborately analyzed through in situ characterizations and DFT calculations using representative cases.Finally,the overall photocatalytic redox reactions were summarized with a focus on the construction of an S-scheme heterojunction photocatalyst,reasonable loading of cocatalysts,photocatalyst morphology regulation,novel photocatalyst development,reasonable selection of the oxidation half-reaction and reduction half-reaction for coupling,and combined in situ characterization and DFT calculations.This work provides a reference for promising design strategies and insight into the mechanism of overall photocatalytic redox reactions.展开更多
Small-sized Cd_(x) Zn_(1-x) S solid solution nanomaterial is an important candidate for efficient photocatalytic hydrogen evolution(PHE),but it still suffers from easy agglomeration,severe photo corrosion,and fast pho...Small-sized Cd_(x) Zn_(1-x) S solid solution nanomaterial is an important candidate for efficient photocatalytic hydrogen evolution(PHE),but it still suffers from easy agglomeration,severe photo corrosion,and fast photogenerated electron-hole recombination.To tackle these issues,herein,we propose a new strategy to modify Cd_(x) Zn_(1-x) S nanoreactors by the simultaneous utilization of ionic-liquid-assisted morphology engineering and MXene-incorporating method.That is,we designed and synthesized a novel hierarchi-cal Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction composite through the in-situ deposition of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets on unique IL-modified Ti_(3) C_(2) MXenes by a one-pot solvothermal method for efficiently PHE.The unique construction strategy tailors the thickness of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets and prevents them from stacking and agglomeration,and especially,optimizes their charge transfer pathways during the photocatalytic process.Compared with pristine Cd_(0.8) Zn_(0.2) S nanosheets,Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) has abun-dant photogenerated electrons available on the Ti_(3) C_(2) surface for proton reduction reaction,owing to the absence of deep-trapped electrons,suppression of electron-hole recombination in Cd_(0.8) Zn_(0.2) S and high-efficiency charge separation at the Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction interface.Moreover,the hy-drophilicity,electrical conductivity,visible-light absorption capacity,and surficial hydrogen desorption of Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) heterostructure are significantly improved.As a result,the heterostructure exhibits out-standing photocatalytic stability and super high apparent quantum efficiency,being rendered as one of the best noble-metal-free Cd-Zn-S-based photocatalysts.This work illustrates the mechanisms of mor-phology control and heterojunction construction in controlling the catalytic behavior of photocatalysts and highlights the great potential of the IL-assisted route in the synthesis of high-performance MXene-based heterostructures for photocatalytic hydrogen evolution.展开更多
Cu-Mn co-doped CeO_(2) photocatalyst was successfully synthesized by the sol-gel method to assess its capability in degrading tetracycline.XRD and TEM results showed that Cu and Mn were successfully co-doped into CeO_...Cu-Mn co-doped CeO_(2) photocatalyst was successfully synthesized by the sol-gel method to assess its capability in degrading tetracycline.XRD and TEM results showed that Cu and Mn were successfully co-doped into CeO_(2) without forming heterostructure,XPS and photoelectrochemical results revealed that Mn ions doping amplified the generation of photo-induced charge carriers,while Cu ions doping significantly facilitated the interfacial charge transfer process.Notably,the optimized Cu3Mn2CeO_(2) nanoparticles exhibited the highest TC removal efficiency,achieved a rate of 78.18%and maintained a stable cycling performance.展开更多
This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal me...This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal method,demonstrating a significant improvement in photocatalytic NO removal under visible light irradiation.For high-flux simulated flue gas,the composite with 10%SnS_(2)(denoted as SNCN-10)showed exceptional NO removal efficiency,reaching up to 66.8%,along with excellent reusability over five consecutive cycles.Detailed band structure and density of states(DOS)calculations confirmed the formation of a characteristic heterojunction.Spin-trapping ESR spectroscopy identified·O_(2)^(-)−as the key reactive species driving NO oxidation.Additionally,in situ DRIFT spectroscopy revealed that SNCN-10 facilitated the conversion of NO to nitrate through intermediate species,including bridging nitrite and cis-nitrite(N_(2)O_(2)^(2-)).Kinetic studies further indicated that NO oxidation followed the Langmuir-Hinshelwood(L-H)mechanism.Based on density functional theory(DFT)calculations of free energy changes,a comprehensive reaction pathway for NO oxidation was proposed.These findings provide valuable insights for the development of efficient photocatalytic strategies for NO removal.展开更多
The article contains an error regarding the electron spectra displayed in Figs.4 and 5 and the data extracted from these spectra.The measurements were made with the SESAME magnetic spectrometer,the working principle o...The article contains an error regarding the electron spectra displayed in Figs.4 and 5 and the data extracted from these spectra.The measurements were made with the SESAME magnetic spectrometer,the working principle of which is recalled in Fig.1.Specifically,a magnetic dipole is used to separate charged particles(electrons in the case of this experiment)depending on their energy,charge and mass.The deflected particles then hit an imaging plate(IP)and deposit energy in its sensitive layer.The kinetic energy of the particles can be evaluated from their impact position on the IP and their number can be inferred from the local energy deposition.展开更多
The rise in global energy demand and environmental pollution highlights the importance of developing efficient and stable photocatalytic materials to address the energy crisis and environmental issues.Graded nanomater...The rise in global energy demand and environmental pollution highlights the importance of developing efficient and stable photocatalytic materials to address the energy crisis and environmental issues.Graded nanomaterials exhibit significant promise for photocatalysis due to their unique structural advantages,including multi-scale pores,high specific surface area,and optimized electron transport pathways.This review systematically examines the design principles and synthesis methods for hierarchical nanomaterials and their photocatalytic performance.Through modulation of porous structures,hierarchical heterojunctions,and core-shell configurations,graded nanomaterials notably improve light absorption efficiency,carrier separation,and surface reaction activity of photocatalysts.Strategies such as S-scheme heterojunctions and interface engineering further enhance the performance of photocatalysts for CO_(2)reduction,hydrogen production,and pollutant degradation.In situ characterization techniques offer dynamic insights into the photocatalytic mechanism.This study elucidates how hierarchical structures influence photocatalytic performance,discusses their potential applications in environmental treatment and clean energy,and proposes directions for future design and optimization of photocatalytic materials.展开更多
Poly(heptazine imide)(PHI),a new allotrope of heptazine-based carbon nitride,is usually synthesized in the presence of binary molten salts(e.g.,LiCl/NaCl,LiCl/KCl,NaCl/KCl)with diverse melting points and solvation abi...Poly(heptazine imide)(PHI),a new allotrope of heptazine-based carbon nitride,is usually synthesized in the presence of binary molten salts(e.g.,LiCl/NaCl,LiCl/KCl,NaCl/KCl)with diverse melting points and solvation abilities.However,the quantum efficiency of PHI for photocatalytic hydrogen production is still extremely restrained.Herein,a series of ternary molten salt mixtures(LiCl/NaCl/KCl)with varying compositions and properties,were employed for the rational control of the polymerization process of PHI and thus optimization in the optical properties,charge separation behaviors,and also photocatalytic performance.The results indicate that the ternary molten salts provide suitable environment for the development of a nanorod morphology,which significantly improves separation of photo-induced charge carriers.Hence,the optimized PHI presents a high apparent quantum yield(AQY=52.9%)for visible-light driven hydrogen production.展开更多
Developing heterojunction photocatalyst with well-matched interfaces andmultiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal,but still remains a great c...Developing heterojunction photocatalyst with well-matched interfaces andmultiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal,but still remains a great challenge.In present work,a new strategy of chloride anion intercalation in Bi_(2)O_(3)via one-pot hydrothermal process is proposed.The as-prepared Ta-BiOCl/Bi_(24)O_(31)Cl_(10)(TBB)heterojunctions are featured with Ta-Bi_(24)O_(31)Cl_(10)and Ta-BiOCl lined shoulder-by-shouleder via semi-coherent interfaces.In this TBB heterojunctions,the well-matched semi-coherent interfaces and shoulder-by-shoulder structures provide fast electron transfer andmultiple transfer paths,respectively,leading to enhanced visible light response and improved photogenerated charge separation.Meanwhile,a type-II heterojunction for photocharge separation has been obtained,in which photogenerated electrons are drove from the CB(conduction band)of Ta-Bi_(24)O_(31)Cl_(10)to the both of bilateral empty CB of Ta-BiOCl and gathered on the CB of Ta-BiOCl,while the photogenerated holes are left on the VB(valence band)of Ta-Bi_(24)O_(31)Cl_(10),effectively hindering the recombination of photogenerated electron-hole pairs.Furthermore,the separated electrons can effectively activate dissolved oxygen for the generation of reactive oxygen species(·O_(2)^(−)).Such TBB heterojunctions exhibit remarkably superior photocatalytic degradation activity for tetracycline hydrochloride(TCH)solution to Bi_(2)O_(3),Ta-BiOCl and Ta-Bi_(24)O_(31)Cl_(10).This work not only proposes a Ta-BiOCl/Bi_(24)O_(31)Cl_(10)shoulder-by-shoulder micro-ribbon architectures with semi-coherent interfaces and successive type-Ⅱheterojunction for highly efficient photocatalytic activity,but offers a new insight into the design of highly efficient heterojunction through phasestructure synergistic transformation strategy.展开更多
Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises.Among various methods,photoelectrochemical(PEC)water spli...Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises.Among various methods,photoelectrochemical(PEC)water splitting stands out as a promising approach for direct solar-driven hydrogen production.Enhancing the efficiency and stability of photoelectrodes is a key focus in PEC water-splitting research.Tantalum nitride(Ta_(3)N_(5)),with its suitable band gap and band-edge positions for PEC water splitting,has emerged as a highly promising photoanode material.This review begins by introducing the history and fundamental characteristics of Ta_(3)N_(5),emphasizing both its advantages and challenges.It then explores methods to improve light absorption efficiency,charge separation and transfer efficiency,surface reaction rate,and the stability of Ta_(3)N_(5) photoanodes.Additionally,the review discusses the progress of research on tandem PEC cells incorporating Ta_(3)N_(5) photoanodes.Finally,it looks ahead to future research directions for Ta_(3)N_(5) photoanodes.The strategic approach outlined in this review can also be applied to other photoelectrode materials,providing guidance for their development.展开更多
Photocatalytic overall water splitting is a promising method for producing clean hydrogen energy,but faces challenges such as low light utilization efficiency and high charge carrier recombination rates.This study dem...Photocatalytic overall water splitting is a promising method for producing clean hydrogen energy,but faces challenges such as low light utilization efficiency and high charge carrier recombination rates.This study demonstrates that dielectric Mie resonance in TiO_(2)hollow nanoshells can enhance electric field intensity and increase light absorption through resonant energy transfer,compared to crushed TiO_(2)nanoparticles.The Mie resonance effect was confirmed through fluorescence spectra,photo-response current measurements,photocatalytic water splitting experiments,and Mie calculation.The incident electricfield amplitude was doubled in hollow nanoshells,allowing for increased light trapping.Additionally,the spatially separated Pt and RuO_(2)cocatalysts on the inner and outer surfaces facilitated the separation of photoinduced electrons and holes.Pt@TiO_(2)@RuO_(2)hollow nanoshells exhibited superior photocatalytic water splitting performance,with a stable H_(2)generation rate of 50.1μmol g^(−1)h^(−1)and O_(2)evolution rate of 25.1μmol g^(−1)h^(−1),outperforming other nanostructures such as TiO_(2),Pt@TiO_(2),and TiO_(2)@RuO_(2)hollow nanoshells.This study suggests that dielectric Mie resonance and spatially-separated cocatalysts offer a new approach to simultaneously enhance light absorption and charge carrier transfer in photocatalysis.展开更多
A novel square-shaped metallacycle M,functionalized with carbazole and benzothiadiazole,was synthesized through coordination-driven self-assembly.The discrete metallacyclic architecture endows M with superior optical ...A novel square-shaped metallacycle M,functionalized with carbazole and benzothiadiazole,was synthesized through coordination-driven self-assembly.The discrete metallacyclic architecture endows M with superior optical properties owing to its rigid metallacyclic skeleton and donor-acceptor electronic structure.The femtosecond transient absorption(fs-TA)spectroscopic measurements demonstrated that the macrocyclic skeleton significantly promotes the intramolecular charge transfer efficiency and the rapid formation of triplet states.Furthermore,leveraging M as a photocatalyst enabled to drive the cross-dehydrogenative coupling(CDC)reactions with>90%efficiency,which was facilitated by its persistent charge separation states and long-lived triplet states.This work highlights the critical role of metallacycle engineering in optimizing photophysical dynamics and advancing applications in smart optoelectronics and sustainable photocatalysis.展开更多
The interface modulation significantly affects the photocatalytic performances of supported metal phthalocyanines(MPc)-based systems.Herein,ZnPc was loaded on nanosized Au-modified TiO_(2)nanosheets(Au-T)to obtain wid...The interface modulation significantly affects the photocatalytic performances of supported metal phthalocyanines(MPc)-based systems.Herein,ZnPc was loaded on nanosized Au-modified TiO_(2)nanosheets(Au-T)to obtain wide-spectrum ZnPc/Au-T photocatalysts.Compared with large Au NP(8 nm)-mediated ZnPc/Au-T photocatalyst,ultrasmall Au NP(3 nm)-mediated one shows advantageous photoactivity,achieving 3-and 10-fold CO_(2)conversion rates compared with reference ZnPc/T and pristine TiO_(2)nanosheets,respectively.Employing monochromatic beam-assisted surface photovoltage and photocurrent action,etc.,the introduction of ultrasmall Au NPs more effectively facilitates intrinsic interfacial charge transfer.Moreover,ZnP c molecules are found more dispersed with the existence of small Au NPs hence exposing abundant Zn^(2+)sites as the catalytic center for CO_(2)reduction.This work provides a feasible design strategy and renewed recognition for supported MPc-based photocatalyst systems.展开更多
This study aims to increase the photoactivity of ZnSnO_(3)by modifying it with zeolitic imidazolate framework-8(ZIF-8).The composite catalyst was prepared by a straightforward hydrothermal method using ZnSnO_(3)as the...This study aims to increase the photoactivity of ZnSnO_(3)by modifying it with zeolitic imidazolate framework-8(ZIF-8).The composite catalyst was prepared by a straightforward hydrothermal method using ZnSnO_(3)as the zinc source.The in-situ generated ZnSnO_(3)/ZIF-8 composite exhibits a strong interaction between ZnSnO_(3)and ZIF-8,which benefits electron transfer.Band structure analysis shows that ZIF-8 has a higher conduction band and a lower valence band than ZnSnO_(3),and cannot form a typical heterojunction.However,defects in ZIF-8 may act as electron traps,accepting electrons from the conduction band of ZnSnO_(3).This atypical heterojunction results in the spatial separation of charge carriers within the composite.The transient photocurrent response,electrochemical impedance spectroscopy,and photoluminescence analysis confirmed this hypothesis.Meanwhile,ZIF-8 also plays a role in adsorbing dyes and concentrating reactants due to its extremely high specific surface area.Therefore,the ZnSnO_(3)/ZIF-8 composite exhibits significantly improved photocatalytic performance in Rhodamine B degradation.The degradation rate of the best sample was 10.4 times that of ZnSnO_(3).Active species capture experiments showed that holes and superoxide radicals were the main active species.Additionally,the ZnSnO_(3)/ZIF-8 composite showed enhanced photocatalytic activity in CO_(2)reduction.This study may show new insights into the design of efficient photocatalytic materials using metal-organic framework materials.展开更多
Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO_(2)splitting into value-added chemicals has suffered from th...Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO_(2)splitting into value-added chemicals has suffered from the poor activity and remained in great challenge for real application.Herein,hydrothermally synthesized BiOCl with layered structure(BOC-NSs)was exfoliated into thickness reduced nanosheets(BOCNSs-w)and even atomic layers(BOCNSs-i)via ultrasonication in water and isopro-panol,respectively.In comparison with the pristine BOCNSs,the exfoli-ated BiOCl,especially BOCNSs-i with atomically layered structure,exhibits much improved photocatalytic activity forCO_(2)overall splitting to produce CO andO_(2) at a stoichiometric ratio of 2:1,with CO evolution rate reaching 134.8µmolg^(-1)h^(-1) under simulated solar light(1.7 suns).By surpassing the photocatalytic performances of the state-of-the-artBi_(l)O_(m)X_(n)(X:Cl,Br,I)based photocatalysts,the CO evolution rate is further increased by 99 times,reaching 13.3 mmolg^(-1)h^(-1) under concentrated solar irradiation(34 suns).This excellent photocatalytic performance achieved over BOCNSs-i should be benefited from the shortened transfer distance and the increased built-in electric field intensity,which acceler-ates the migration of photogenerated charge carriers to surface.Moreover,with oxygen vacancies(VO)introduced into the atomic layers,BOCNSs-i is exposed with the electrons enriched Bi active sites that could transfer electrons to activateCO_(2)molecules for highly efficient and selective CO production,by lowering the energy barrier of rate-determining step(RDS),*OH+*CO_(2)-→HCO_(3)-.It is also realized that theH_(2)O vapor supplied during photocatalytic reaction would exchange oxygen atoms withCO_(2),which could alter the reaction path-ways and further reduce the energy barrier of RDS,contributing to the dramatically improved photocatalytic performance forCO_(2)overall splitting to CO andO_(2).展开更多
The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limit...The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limited by sluggish water oxidation kinetics,poor photogenerated charge separation,and insufficient O_(2)adsorption and activation capabilities.Herein,uniformly dispersed single-atom catalysts(SACs)with a Co-N_(4)coordination structure have been synthesized by thermally transforming cobalt phthalocyanine(CoPc)assemblies pre-anchored on phosphate functionalized reduced graphene oxide(Co@rGO-P),and then used to construct heterojunctions with perylenetetracarboxylic acid(PTA)nanosheets for photocatalytic H_(2)O_(2)production by an in-situ growth method.The optimized Co@rGO-P/PTA achieved an H_(2)O_(2)production rate of 1.4 mmol g^(-1)h^(-1)in pure water,with a 12.9-fold enhancement compared to pristine PTA nanosheets exhibiting competitive photoactivity among reported perylene-based materials.Femtosecond transient absorption spectra,in-situ diffuse reflectance infrared Fourier transform spectra and theoretical calculations reveal that the exceptional performance is attributed to the enhanced electron transfer from PTA to rGO via the phosphate bridge and then to the Co-N_(4),and to the promoted O_(2)adsorption and activation at Co-N_(4)active sites.This work provides a feasible and effective strategy for designing highly efficient single-atom semiconductor heterojunction photocatalysts for H_(2)O_(2)production.展开更多
Simultaneously inducing dual built-in electric fields(EFs)both within a single component and at the heterojunction interface creates a dual-driving force that is crucial for promoting spatial charge separation.This is...Simultaneously inducing dual built-in electric fields(EFs)both within a single component and at the heterojunction interface creates a dual-driving force that is crucial for promoting spatial charge separation.This is particularly significant in challenging coupled systems,such as CO_(2)photoreduction integrated with selective oxidation of toluene to benzaldehyde.However,developing such a system is quite challenging and often requires a precise design and engineering.Herein,we demonstrate a unique Ni-CdS@Ni(OH)_(2)heterojunction synthesized via an in-situ self-assembly method.Comprehensive mechanistic and theoretical investigations reveal that the NiCdS@Ni(OH)_(2)heterojunction induces dual electric fields(EFs):an intrinsic polarized electric-field within the CdS lattice from Ni doping and an interfacial electric-field from the growth of ultrathin nanosheets of Ni(OH)_(2)on NiCdS nanorods,enabling efficient spatial charge separation and enhanced redox potential.As proof of concept,the Ni-CdS@Ni(OH)_(2)heterojunction simultaneously exhibits outstanding bifunctional photocatalytic performance,producing CO at a rate of 427μmol g^(-1)h^(-1)and selectively oxidizing toluene to benzaldehyde at a rate of 1476μmol g^(-1)h^(-1)with a selectivity exceeding 85%.This work offers a promising strategy to optimize the utilization of photogenerated carriers in heterojunction photocatalysts,advancing synergistic photocatalytic redox systems.展开更多
Photocatalytic reduction of CO_(2)into high-value C_(2)H_(4)offers a promising pathway toward carbon neutrality.Due to the continuous 12-electron-proton coupled reactions and the mutual repulsion of reaction intermedi...Photocatalytic reduction of CO_(2)into high-value C_(2)H_(4)offers a promising pathway toward carbon neutrality.Due to the continuous 12-electron-proton coupled reactions and the mutual repulsion of reaction intermediates,achieving highly selective photocatalytic conversion of CO_(2)to C_(2)H_(4)remains challenging.This work synthesized a CuInS_(2)/CuS heterojunction photocatalyst mediated by a sulfur electron bridge via a one-step solvothermal method,achieving a high selectivity for C_(2)H_(4)conversion(98.22%).The sulfur electron bridge minimized the contact energy barrier between CuInS_(2)and CuS to enhance photogenerated carrier separation efficiency,while the asymmetric active sites in CuInS_(2)effectively reduced mutual repulsion of reaction intermediates.This work develops a hybrid catalytic system enabling synergistic regulation of reaction kinetics and thermodynamics,offering an innovative strategy for highly selective photocatalytic CO₂-to-C_(2)H_(4)production.展开更多
Photocatalytic oxidation of toluene to valuable benzaldehyde offers a promising pathway for sustainable production of fine chemicals and pharmaceuticals.In this process,photogenerated holes play a crucial role in C(sp...Photocatalytic oxidation of toluene to valuable benzaldehyde offers a promising pathway for sustainable production of fine chemicals and pharmaceuticals.In this process,photogenerated holes play a crucial role in C(sp^(3))-H bond dissociation.However,the photocatalytic performance of current photocatalysts is often hindered by the low separation and transfer efficiency of photogenerated charges.In this work,we presented a perovskite-based heterostructure via in situ growth of defective WO_(3-x)nanosheets on Cs_(2)AgBiBr_(6)nanoparticles for photocatalytic toluene transformation.In situ Fourier transform infrared spectroscopy tests proved the introduction of oxygen-deficient WO_(3)-xcomponent enhanced the chemisorption of molecular oxygen.The in situ electron paramagnetic resonance and 4-chloro-7-nitro-1,2,3-benzoxadiazole fluorescence measurements further confirmed the presence of oxygen vacancies,and the formation of heterostructure synergistically accelerated the formation of the superoxide radicals and the transfer of photogenerated charge carriers.Under visible light irradiation,Cs_(2)AgBiBr_(6)/WO_(3-x)photocatalyst could effectively oxidize toluene toward benzaldehyde with a conversion rate of 9020μmol g^(-1)h^(-1),which was a 3.5-fold increase over that of the unmodified Cs_(2)AgBiBr_(6).展开更多
基金Supported by the Doctoral Research Start-up Project of Yuncheng University(YQ-2023067)Project of Shanxi Natural Science Foundation(202303021211189)+1 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provinces(20220036)Shanxi ProvinceIntelligent Optoelectronic Sensing Application Technology Innovation Center and Shanxi Province Optoelectronic Information Science and TechnologyLaboratory,Yuncheng University.
文摘In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.
基金supported by the National Natural Science Foundation of China(No.42403080)the Youth Innovation Promotion Asso-ciation of the Chinese Academy of Sciences(No.2022415)+1 种基金the Key Research and Development Program of Shaanxi Province(No.S2023-YF-LLRH-QCYK-0263)the Key Research and Development Programof Shaanxi Province(No.2023QCY-LL-16).
文摘The development of ZnO-based composites with high charge separation and effective inhibition of toxic by-products is admirable for effective photocatalysis of nitrogen oxides(NO_(x))oxidation.In this study,carbon quan-tum dots(CQDs)/ZnO hollow microspheres,synthesized through a rapid microwave-assisted method,achievedover a 30-fold higher NO_(x) removal efficiency compared to ZnO,with complete inhibition of NO_(2) by-products andgood durability.The enhanced photocatalytic activity was ascribed to the unique role of CQDs,as revealed byin-situ photoelectric techniques.Results demonstrated that the electron directional migration from ZnO to CQDsat the composite interface accounts for the enhanced charge separation.Active free radicals for NO_(x) oxidationwere identified,and in-situ diffuse reflectance infrared Fourier transform spectroscopy analysis elucidated theconversion pathways of NO_(x) oxidation under visible light irradiation.This work sheds light on the mechanismsof electron transfer and charge separation at the composite interface,offering guidance for designing superiorZnO-based photocatalysts for complete NO_(x) removal.
文摘The photoconversion of CO_(2) to carbon-containing fuels,splitting water into H_(2),selective organic synthesis,reduction of N_(2) to NH3,and hazardous organic contaminant degradation represent feasible schemes for solving environmental and energy issues.In 1972,TiO_(2) was applied for decomposing water into H_(2) and O_(2) via photocatalysis.Owing to its the low visible-light utilization,fast charge recombination,and high energy barrier for water oxidation,overall photocatalytic water-splitting efficiency is extremely low.Because H_(2) is more economically valuable than O_(2),sacrificial agent-assisted photocatalytic H_(2) evolution has been extensively investigated.Because the sacrificial agent can quickly consume photoexcited holes and effectively reduce the water oxidation energy barrier,photocatalytic H_(2) evolution efficiency can be increased by 3-4 orders of magnitude compared to photocatalytic water splitting.However,the overuse of sacrificial agents contributes to wasted photoexcited holes and expensive processes,while presenting potential environmental issues.Recently,overall charge utilization and improved redox efficiency have been achieved by coupling photocatalytic reduction with oxidation reactions.Moreover,overall charge utilization can boost charge separation and increase photocatalyst durability.However,the photocatalytic mechanism of the overall redox reactions remains unclear,owing to the complex reaction processes and design difficulties.Herein,the basic principles of photocatalysis are discussed from the perspective of light harvesting,photoexcited charge separation,thermodynamics,and redox reaction kinetics.Photocatalytic redox reactions,including overall water photodecomposition,photocatalytic H_(2) evolution coupled with organic oxidation,photocatalytic CO_(2) reduction coupled with organic oxidation,photocatalytic H_(2)O_(2) production coupled with organic oxidation,photocatalytic N_(2) reduction coupled with N_(2) oxidation,and photocatalytic organic reduction coupled with organic oxidation,can be systematically classified according to the coupling of photocatalytic oxidation reactions with photocatalytic reduction reactions.Subsequently,the design of photocatalytic redox reactions is considered in terms of the modulation of photocatalyst materials,reaction conditions,and diversity of reactants and products.In addition,the vital role of density functional theory(DFT)calculations for unveiling photoexcited charge transfer,rate-determining steps,and redox reaction barriers are discussed in the context of the work function,electron density difference,Bader charge,and variation in the intermediate adsorption free energy profiles.The activity and mechanism of various photocatalytic redox reactions were elaborately analyzed through in situ characterizations and DFT calculations using representative cases.Finally,the overall photocatalytic redox reactions were summarized with a focus on the construction of an S-scheme heterojunction photocatalyst,reasonable loading of cocatalysts,photocatalyst morphology regulation,novel photocatalyst development,reasonable selection of the oxidation half-reaction and reduction half-reaction for coupling,and combined in situ characterization and DFT calculations.This work provides a reference for promising design strategies and insight into the mechanism of overall photocatalytic redox reactions.
基金financial supports pro-vided by the National Natural Science Foundation of China(No.21905279)the Natural Science Foundation of Fujian Province(No.2020J05086).
文摘Small-sized Cd_(x) Zn_(1-x) S solid solution nanomaterial is an important candidate for efficient photocatalytic hydrogen evolution(PHE),but it still suffers from easy agglomeration,severe photo corrosion,and fast photogenerated electron-hole recombination.To tackle these issues,herein,we propose a new strategy to modify Cd_(x) Zn_(1-x) S nanoreactors by the simultaneous utilization of ionic-liquid-assisted morphology engineering and MXene-incorporating method.That is,we designed and synthesized a novel hierarchi-cal Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction composite through the in-situ deposition of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets on unique IL-modified Ti_(3) C_(2) MXenes by a one-pot solvothermal method for efficiently PHE.The unique construction strategy tailors the thickness of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets and prevents them from stacking and agglomeration,and especially,optimizes their charge transfer pathways during the photocatalytic process.Compared with pristine Cd_(0.8) Zn_(0.2) S nanosheets,Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) has abun-dant photogenerated electrons available on the Ti_(3) C_(2) surface for proton reduction reaction,owing to the absence of deep-trapped electrons,suppression of electron-hole recombination in Cd_(0.8) Zn_(0.2) S and high-efficiency charge separation at the Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction interface.Moreover,the hy-drophilicity,electrical conductivity,visible-light absorption capacity,and surficial hydrogen desorption of Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) heterostructure are significantly improved.As a result,the heterostructure exhibits out-standing photocatalytic stability and super high apparent quantum efficiency,being rendered as one of the best noble-metal-free Cd-Zn-S-based photocatalysts.This work illustrates the mechanisms of mor-phology control and heterojunction construction in controlling the catalytic behavior of photocatalysts and highlights the great potential of the IL-assisted route in the synthesis of high-performance MXene-based heterostructures for photocatalytic hydrogen evolution.
基金Funded by the Scientific Research Fund of Wuhan Institute of Technology(No.K2023055)the Key Research and Development Project of Hubei Province(No.2020BCA075)the Shccig-Qinling Program(No.2022QL-XM-ZhuLi-HG-006)。
文摘Cu-Mn co-doped CeO_(2) photocatalyst was successfully synthesized by the sol-gel method to assess its capability in degrading tetracycline.XRD and TEM results showed that Cu and Mn were successfully co-doped into CeO_(2) without forming heterostructure,XPS and photoelectrochemical results revealed that Mn ions doping amplified the generation of photo-induced charge carriers,while Cu ions doping significantly facilitated the interfacial charge transfer process.Notably,the optimized Cu3Mn2CeO_(2) nanoparticles exhibited the highest TC removal efficiency,achieved a rate of 78.18%and maintained a stable cycling performance.
基金The project was supported by Natural Science Foundation of Shandong Province(ZR2021MB104)National Natural Science Foundation of China(22078174).
文摘This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal method,demonstrating a significant improvement in photocatalytic NO removal under visible light irradiation.For high-flux simulated flue gas,the composite with 10%SnS_(2)(denoted as SNCN-10)showed exceptional NO removal efficiency,reaching up to 66.8%,along with excellent reusability over five consecutive cycles.Detailed band structure and density of states(DOS)calculations confirmed the formation of a characteristic heterojunction.Spin-trapping ESR spectroscopy identified·O_(2)^(-)−as the key reactive species driving NO oxidation.Additionally,in situ DRIFT spectroscopy revealed that SNCN-10 facilitated the conversion of NO to nitrate through intermediate species,including bridging nitrite and cis-nitrite(N_(2)O_(2)^(2-)).Kinetic studies further indicated that NO oxidation followed the Langmuir-Hinshelwood(L-H)mechanism.Based on density functional theory(DFT)calculations of free energy changes,a comprehensive reaction pathway for NO oxidation was proposed.These findings provide valuable insights for the development of efficient photocatalytic strategies for NO removal.
文摘The article contains an error regarding the electron spectra displayed in Figs.4 and 5 and the data extracted from these spectra.The measurements were made with the SESAME magnetic spectrometer,the working principle of which is recalled in Fig.1.Specifically,a magnetic dipole is used to separate charged particles(electrons in the case of this experiment)depending on their energy,charge and mass.The deflected particles then hit an imaging plate(IP)and deposit energy in its sensitive layer.The kinetic energy of the particles can be evaluated from their impact position on the IP and their number can be inferred from the local energy deposition.
文摘The rise in global energy demand and environmental pollution highlights the importance of developing efficient and stable photocatalytic materials to address the energy crisis and environmental issues.Graded nanomaterials exhibit significant promise for photocatalysis due to their unique structural advantages,including multi-scale pores,high specific surface area,and optimized electron transport pathways.This review systematically examines the design principles and synthesis methods for hierarchical nanomaterials and their photocatalytic performance.Through modulation of porous structures,hierarchical heterojunctions,and core-shell configurations,graded nanomaterials notably improve light absorption efficiency,carrier separation,and surface reaction activity of photocatalysts.Strategies such as S-scheme heterojunctions and interface engineering further enhance the performance of photocatalysts for CO_(2)reduction,hydrogen production,and pollutant degradation.In situ characterization techniques offer dynamic insights into the photocatalytic mechanism.This study elucidates how hierarchical structures influence photocatalytic performance,discusses their potential applications in environmental treatment and clean energy,and proposes directions for future design and optimization of photocatalytic materials.
基金financially supported by the National Key R&D Program of China(No.2021YFA1502100)the National Natural Science Foundation of China(Nos.22472029,22172029,22311540011)+1 种基金the Natural Science Foundation of the Fujian Province(No.2024J010014)111 Project(No.D16008)。
文摘Poly(heptazine imide)(PHI),a new allotrope of heptazine-based carbon nitride,is usually synthesized in the presence of binary molten salts(e.g.,LiCl/NaCl,LiCl/KCl,NaCl/KCl)with diverse melting points and solvation abilities.However,the quantum efficiency of PHI for photocatalytic hydrogen production is still extremely restrained.Herein,a series of ternary molten salt mixtures(LiCl/NaCl/KCl)with varying compositions and properties,were employed for the rational control of the polymerization process of PHI and thus optimization in the optical properties,charge separation behaviors,and also photocatalytic performance.The results indicate that the ternary molten salts provide suitable environment for the development of a nanorod morphology,which significantly improves separation of photo-induced charge carriers.Hence,the optimized PHI presents a high apparent quantum yield(AQY=52.9%)for visible-light driven hydrogen production.
基金supported by the National Natural Science Foundation of China(Nos.22208262,52271228,52202298,52201279,51834009,and 51801151)the Natural Science Foundation of Shaanxi Province(Nos.2021JQ-468,2020JZ-47)+3 种基金the Natural Science Foundation of Shaanxi Provincial Department of Education(No.21JP086)the Postdoctoral Research Foundation of China(Nos.2020M683528 and 2018M633643XB)the Young Talent Fund of Association for Science and Technology in Shaanxi,China(No.20230625)the Hundred Talent Program of Shaanxi Province.
文摘Developing heterojunction photocatalyst with well-matched interfaces andmultiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal,but still remains a great challenge.In present work,a new strategy of chloride anion intercalation in Bi_(2)O_(3)via one-pot hydrothermal process is proposed.The as-prepared Ta-BiOCl/Bi_(24)O_(31)Cl_(10)(TBB)heterojunctions are featured with Ta-Bi_(24)O_(31)Cl_(10)and Ta-BiOCl lined shoulder-by-shouleder via semi-coherent interfaces.In this TBB heterojunctions,the well-matched semi-coherent interfaces and shoulder-by-shoulder structures provide fast electron transfer andmultiple transfer paths,respectively,leading to enhanced visible light response and improved photogenerated charge separation.Meanwhile,a type-II heterojunction for photocharge separation has been obtained,in which photogenerated electrons are drove from the CB(conduction band)of Ta-Bi_(24)O_(31)Cl_(10)to the both of bilateral empty CB of Ta-BiOCl and gathered on the CB of Ta-BiOCl,while the photogenerated holes are left on the VB(valence band)of Ta-Bi_(24)O_(31)Cl_(10),effectively hindering the recombination of photogenerated electron-hole pairs.Furthermore,the separated electrons can effectively activate dissolved oxygen for the generation of reactive oxygen species(·O_(2)^(−)).Such TBB heterojunctions exhibit remarkably superior photocatalytic degradation activity for tetracycline hydrochloride(TCH)solution to Bi_(2)O_(3),Ta-BiOCl and Ta-Bi_(24)O_(31)Cl_(10).This work not only proposes a Ta-BiOCl/Bi_(24)O_(31)Cl_(10)shoulder-by-shoulder micro-ribbon architectures with semi-coherent interfaces and successive type-Ⅱheterojunction for highly efficient photocatalytic activity,but offers a new insight into the design of highly efficient heterojunction through phasestructure synergistic transformation strategy.
文摘Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises.Among various methods,photoelectrochemical(PEC)water splitting stands out as a promising approach for direct solar-driven hydrogen production.Enhancing the efficiency and stability of photoelectrodes is a key focus in PEC water-splitting research.Tantalum nitride(Ta_(3)N_(5)),with its suitable band gap and band-edge positions for PEC water splitting,has emerged as a highly promising photoanode material.This review begins by introducing the history and fundamental characteristics of Ta_(3)N_(5),emphasizing both its advantages and challenges.It then explores methods to improve light absorption efficiency,charge separation and transfer efficiency,surface reaction rate,and the stability of Ta_(3)N_(5) photoanodes.Additionally,the review discusses the progress of research on tandem PEC cells incorporating Ta_(3)N_(5) photoanodes.Finally,it looks ahead to future research directions for Ta_(3)N_(5) photoanodes.The strategic approach outlined in this review can also be applied to other photoelectrode materials,providing guidance for their development.
基金supported by the National Natural Science Foundation of China(Nos.51702023,62274017)Natural Science Foundation of Jiangsu Province(No.BK20231224)China Postdoctoral Science Foundation(No.2022M711138).
文摘Photocatalytic overall water splitting is a promising method for producing clean hydrogen energy,but faces challenges such as low light utilization efficiency and high charge carrier recombination rates.This study demonstrates that dielectric Mie resonance in TiO_(2)hollow nanoshells can enhance electric field intensity and increase light absorption through resonant energy transfer,compared to crushed TiO_(2)nanoparticles.The Mie resonance effect was confirmed through fluorescence spectra,photo-response current measurements,photocatalytic water splitting experiments,and Mie calculation.The incident electricfield amplitude was doubled in hollow nanoshells,allowing for increased light trapping.Additionally,the spatially separated Pt and RuO_(2)cocatalysts on the inner and outer surfaces facilitated the separation of photoinduced electrons and holes.Pt@TiO_(2)@RuO_(2)hollow nanoshells exhibited superior photocatalytic water splitting performance,with a stable H_(2)generation rate of 50.1μmol g^(−1)h^(−1)and O_(2)evolution rate of 25.1μmol g^(−1)h^(−1),outperforming other nanostructures such as TiO_(2),Pt@TiO_(2),and TiO_(2)@RuO_(2)hollow nanoshells.This study suggests that dielectric Mie resonance and spatially-separated cocatalysts offer a new approach to simultaneously enhance light absorption and charge carrier transfer in photocatalysis.
基金supported by the National Natural Science Foundation of China(Nos.22301079 and 22473002)the University Annual Scientific Research Plan of Anhui Province(No.2022AH010013)Anhui Province Key Laboratory for Control and Application of Optoelectronic Information Materials(No.OIM-2024-09).
文摘A novel square-shaped metallacycle M,functionalized with carbazole and benzothiadiazole,was synthesized through coordination-driven self-assembly.The discrete metallacyclic architecture endows M with superior optical properties owing to its rigid metallacyclic skeleton and donor-acceptor electronic structure.The femtosecond transient absorption(fs-TA)spectroscopic measurements demonstrated that the macrocyclic skeleton significantly promotes the intramolecular charge transfer efficiency and the rapid formation of triplet states.Furthermore,leveraging M as a photocatalyst enabled to drive the cross-dehydrogenative coupling(CDC)reactions with>90%efficiency,which was facilitated by its persistent charge separation states and long-lived triplet states.This work highlights the critical role of metallacycle engineering in optimizing photophysical dynamics and advancing applications in smart optoelectronics and sustainable photocatalysis.
基金supported by the National Natural Science Foundation of China(Nos.U2102211 and 22378101)the Fundamental Research Foundation for Universities of Heilongjiang Province(No.2021-KYYWF-0004)the Science Fund for Distinguished Young Scholars of Heilongjiang University(No.JCL202102)。
文摘The interface modulation significantly affects the photocatalytic performances of supported metal phthalocyanines(MPc)-based systems.Herein,ZnPc was loaded on nanosized Au-modified TiO_(2)nanosheets(Au-T)to obtain wide-spectrum ZnPc/Au-T photocatalysts.Compared with large Au NP(8 nm)-mediated ZnPc/Au-T photocatalyst,ultrasmall Au NP(3 nm)-mediated one shows advantageous photoactivity,achieving 3-and 10-fold CO_(2)conversion rates compared with reference ZnPc/T and pristine TiO_(2)nanosheets,respectively.Employing monochromatic beam-assisted surface photovoltage and photocurrent action,etc.,the introduction of ultrasmall Au NPs more effectively facilitates intrinsic interfacial charge transfer.Moreover,ZnP c molecules are found more dispersed with the existence of small Au NPs hence exposing abundant Zn^(2+)sites as the catalytic center for CO_(2)reduction.This work provides a feasible design strategy and renewed recognition for supported MPc-based photocatalyst systems.
基金supported by the National Natural Science Foundation of China(Nos.22172144 and 22272151)the Public Welfare Technology Application Research Project of Jinhua City(No.2023-4-022)the Key Research and Development Program of Zhejiang Province(No.2023C03148).
文摘This study aims to increase the photoactivity of ZnSnO_(3)by modifying it with zeolitic imidazolate framework-8(ZIF-8).The composite catalyst was prepared by a straightforward hydrothermal method using ZnSnO_(3)as the zinc source.The in-situ generated ZnSnO_(3)/ZIF-8 composite exhibits a strong interaction between ZnSnO_(3)and ZIF-8,which benefits electron transfer.Band structure analysis shows that ZIF-8 has a higher conduction band and a lower valence band than ZnSnO_(3),and cannot form a typical heterojunction.However,defects in ZIF-8 may act as electron traps,accepting electrons from the conduction band of ZnSnO_(3).This atypical heterojunction results in the spatial separation of charge carriers within the composite.The transient photocurrent response,electrochemical impedance spectroscopy,and photoluminescence analysis confirmed this hypothesis.Meanwhile,ZIF-8 also plays a role in adsorbing dyes and concentrating reactants due to its extremely high specific surface area.Therefore,the ZnSnO_(3)/ZIF-8 composite exhibits significantly improved photocatalytic performance in Rhodamine B degradation.The degradation rate of the best sample was 10.4 times that of ZnSnO_(3).Active species capture experiments showed that holes and superoxide radicals were the main active species.Additionally,the ZnSnO_(3)/ZIF-8 composite showed enhanced photocatalytic activity in CO_(2)reduction.This study may show new insights into the design of efficient photocatalytic materials using metal-organic framework materials.
基金the financial support from the National Key R&D Program of China(2024YFF0506100)the National Natural Science Foundation of China(52225606 and 52488201).
文摘Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO_(2)splitting into value-added chemicals has suffered from the poor activity and remained in great challenge for real application.Herein,hydrothermally synthesized BiOCl with layered structure(BOC-NSs)was exfoliated into thickness reduced nanosheets(BOCNSs-w)and even atomic layers(BOCNSs-i)via ultrasonication in water and isopro-panol,respectively.In comparison with the pristine BOCNSs,the exfoli-ated BiOCl,especially BOCNSs-i with atomically layered structure,exhibits much improved photocatalytic activity forCO_(2)overall splitting to produce CO andO_(2) at a stoichiometric ratio of 2:1,with CO evolution rate reaching 134.8µmolg^(-1)h^(-1) under simulated solar light(1.7 suns).By surpassing the photocatalytic performances of the state-of-the-artBi_(l)O_(m)X_(n)(X:Cl,Br,I)based photocatalysts,the CO evolution rate is further increased by 99 times,reaching 13.3 mmolg^(-1)h^(-1) under concentrated solar irradiation(34 suns).This excellent photocatalytic performance achieved over BOCNSs-i should be benefited from the shortened transfer distance and the increased built-in electric field intensity,which acceler-ates the migration of photogenerated charge carriers to surface.Moreover,with oxygen vacancies(VO)introduced into the atomic layers,BOCNSs-i is exposed with the electrons enriched Bi active sites that could transfer electrons to activateCO_(2)molecules for highly efficient and selective CO production,by lowering the energy barrier of rate-determining step(RDS),*OH+*CO_(2)-→HCO_(3)-.It is also realized that theH_(2)O vapor supplied during photocatalytic reaction would exchange oxygen atoms withCO_(2),which could alter the reaction path-ways and further reduce the energy barrier of RDS,contributing to the dramatically improved photocatalytic performance forCO_(2)overall splitting to CO andO_(2).
文摘The production of hydrogen peroxide(H_(2)O_(2))via artificial photosynthesis using single-atom semiconductor photocatalysts represents a promising green and sustainable technology.However,its efficiency is still limited by sluggish water oxidation kinetics,poor photogenerated charge separation,and insufficient O_(2)adsorption and activation capabilities.Herein,uniformly dispersed single-atom catalysts(SACs)with a Co-N_(4)coordination structure have been synthesized by thermally transforming cobalt phthalocyanine(CoPc)assemblies pre-anchored on phosphate functionalized reduced graphene oxide(Co@rGO-P),and then used to construct heterojunctions with perylenetetracarboxylic acid(PTA)nanosheets for photocatalytic H_(2)O_(2)production by an in-situ growth method.The optimized Co@rGO-P/PTA achieved an H_(2)O_(2)production rate of 1.4 mmol g^(-1)h^(-1)in pure water,with a 12.9-fold enhancement compared to pristine PTA nanosheets exhibiting competitive photoactivity among reported perylene-based materials.Femtosecond transient absorption spectra,in-situ diffuse reflectance infrared Fourier transform spectra and theoretical calculations reveal that the exceptional performance is attributed to the enhanced electron transfer from PTA to rGO via the phosphate bridge and then to the Co-N_(4),and to the promoted O_(2)adsorption and activation at Co-N_(4)active sites.This work provides a feasible and effective strategy for designing highly efficient single-atom semiconductor heterojunction photocatalysts for H_(2)O_(2)production.
基金The authors sincerely appreciate funding from“Producing Hydrogen in Trentino-H2@TN”(PAT-Trento)through the research grant(SAP 40104237)Researchers Supporting Project number(RSP2025R399)King Saud University,Riyadh,Saudi Arabia.
文摘Simultaneously inducing dual built-in electric fields(EFs)both within a single component and at the heterojunction interface creates a dual-driving force that is crucial for promoting spatial charge separation.This is particularly significant in challenging coupled systems,such as CO_(2)photoreduction integrated with selective oxidation of toluene to benzaldehyde.However,developing such a system is quite challenging and often requires a precise design and engineering.Herein,we demonstrate a unique Ni-CdS@Ni(OH)_(2)heterojunction synthesized via an in-situ self-assembly method.Comprehensive mechanistic and theoretical investigations reveal that the NiCdS@Ni(OH)_(2)heterojunction induces dual electric fields(EFs):an intrinsic polarized electric-field within the CdS lattice from Ni doping and an interfacial electric-field from the growth of ultrathin nanosheets of Ni(OH)_(2)on NiCdS nanorods,enabling efficient spatial charge separation and enhanced redox potential.As proof of concept,the Ni-CdS@Ni(OH)_(2)heterojunction simultaneously exhibits outstanding bifunctional photocatalytic performance,producing CO at a rate of 427μmol g^(-1)h^(-1)and selectively oxidizing toluene to benzaldehyde at a rate of 1476μmol g^(-1)h^(-1)with a selectivity exceeding 85%.This work offers a promising strategy to optimize the utilization of photogenerated carriers in heterojunction photocatalysts,advancing synergistic photocatalytic redox systems.
文摘Photocatalytic reduction of CO_(2)into high-value C_(2)H_(4)offers a promising pathway toward carbon neutrality.Due to the continuous 12-electron-proton coupled reactions and the mutual repulsion of reaction intermediates,achieving highly selective photocatalytic conversion of CO_(2)to C_(2)H_(4)remains challenging.This work synthesized a CuInS_(2)/CuS heterojunction photocatalyst mediated by a sulfur electron bridge via a one-step solvothermal method,achieving a high selectivity for C_(2)H_(4)conversion(98.22%).The sulfur electron bridge minimized the contact energy barrier between CuInS_(2)and CuS to enhance photogenerated carrier separation efficiency,while the asymmetric active sites in CuInS_(2)effectively reduced mutual repulsion of reaction intermediates.This work develops a hybrid catalytic system enabling synergistic regulation of reaction kinetics and thermodynamics,offering an innovative strategy for highly selective photocatalytic CO₂-to-C_(2)H_(4)production.
基金supported by the National Key Research and Development Program of China(No.2021YFA1600800)the National Natural Science Foundation of China(Nos.22102102,22372102,22101185 and 22402122)+8 种基金Shenzhen Science and Technology Program(No.20231122120657001)the City University of Hong Kong Start-Up Fund(No.9020003)ITFRTH-Global STEM Professorship(No.9446006)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010982)Research Team Cultivation Program of Shenzhen University(No.2023QNT013)Scientific Foundation for Youth Scholars of Shenzhen University(868-000001032185)Shenzhen Peacock Plan(Nos.20210308299C,RCJC20200714114434086 and 20231121175024001)Shenzhen Key Laboratory of 2D Metamaterials for Information Technology(No.ZDSYS201707271014468)China Postdoctoral Science Foundation(No.2023M742395)
文摘Photocatalytic oxidation of toluene to valuable benzaldehyde offers a promising pathway for sustainable production of fine chemicals and pharmaceuticals.In this process,photogenerated holes play a crucial role in C(sp^(3))-H bond dissociation.However,the photocatalytic performance of current photocatalysts is often hindered by the low separation and transfer efficiency of photogenerated charges.In this work,we presented a perovskite-based heterostructure via in situ growth of defective WO_(3-x)nanosheets on Cs_(2)AgBiBr_(6)nanoparticles for photocatalytic toluene transformation.In situ Fourier transform infrared spectroscopy tests proved the introduction of oxygen-deficient WO_(3)-xcomponent enhanced the chemisorption of molecular oxygen.The in situ electron paramagnetic resonance and 4-chloro-7-nitro-1,2,3-benzoxadiazole fluorescence measurements further confirmed the presence of oxygen vacancies,and the formation of heterostructure synergistically accelerated the formation of the superoxide radicals and the transfer of photogenerated charge carriers.Under visible light irradiation,Cs_(2)AgBiBr_(6)/WO_(3-x)photocatalyst could effectively oxidize toluene toward benzaldehyde with a conversion rate of 9020μmol g^(-1)h^(-1),which was a 3.5-fold increase over that of the unmodified Cs_(2)AgBiBr_(6).
