The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor ...The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.展开更多
To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesize...To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.展开更多
To enhance the visible light response of titanium dioxide(TiO_(2)),titanium carbide(TiC)nanoparticles(NPs)were thermally treated in carbon powder,effectively overcoming the challenges associated with conventional dopi...To enhance the visible light response of titanium dioxide(TiO_(2)),titanium carbide(TiC)nanoparticles(NPs)were thermally treated in carbon powder,effectively overcoming the challenges associated with conventional doping methods.During the treatment,a TiO_(2)thin shell with oxygen vacancies(OVs)formed around the TiC NPs,creating a shell-core structure S-scheme photocatalyst.Transmission electron microscopy(TEM)and ultraviolet-visible(UV-vis)spectroscopy confirmed the successful formation of the TiO_(2)shell.By optimizing the shell thickness,the TiO_(2)-TiC shell-core structure achieved an ideal shell-core ratio,resulting in strong visible light absorption(400-800 nm),and the degradation rate constant of Rhodamine B(RhB)of sample cHT500 reached 0.0687 min^(−1),which is 20.8times higher than that of pristine TiO_(2)(0.0033 min^(−1))under visible-light irradiation.In addition,cytocompatibility tests showed that sample cHT500 exhibits favorable cell viability,which is comparable to that of TiO_(2)nanoparticles,and thus remarkably mitigates the poor biocompatibility inherent to TiC,making them promising candidates for biomedical and photocatalytic applications.展开更多
Innovative S-scheme heterostructures face intrinsic limitations in charge separation due to insufficient interfacial driving forces.This work pioneers a dual-vacancy engineering strategy to break this bottleneck,const...Innovative S-scheme heterostructures face intrinsic limitations in charge separation due to insufficient interfacial driving forces.This work pioneers a dual-vacancy engineering strategy to break this bottleneck,constructing a plasmonic ZnIn_(2)S_(4-x)MoO_(3-x)(ZIS/MO)S-scheme heterojunction where oxygen and sulfur vacancies synergistically reconfigure charge transfer dynamics via dual-path modulation.Uniquely,sulfur vacancies amplify the built-in electric field(IEF)intensity by enlarging the Fermi level gap,while oxygen and sulfur dual-vacancies induce localized surface plasmon resonance(LSPR)via free-carrier concentration enhancement.Simultaneously,sulfur vacancies lower the H^(*)adsorption barrier,and dual vacancies amplify photothermal conversion by promoting nonradiative decay,accelerating temperature elevation and kinetics.Electron dynamics confirm that this dual-vacancy synergy prolongs charge carrier lifetime by a factor of 5.23.Consequently,the optimized sulfur vacancy-rich ZnIn_(2)S_(4-x)/MoO_(3-x)(R-ZIS/MO)exhibits remarkable photocatalytic hydrogen production rates of 3.60 mmol g^(-1) h^(-1)under visible light and 22.74 mmol g^(-1) h^(-1) under full-spectrum irradiation,representing 7.8-fold and17.2-fold enhancements,respectively.This study establishes a new paradigm.Targeted dual-vacancy coordination in plasmonic heterostructures enables unprecedented IEF-LSPR co-modulation,opening avenues for high-efficiency solar energy conversion.展开更多
The process of utilizing solar-driven semiconductor water splitting for the production of hydrogen is a vital strategy in the pursuit of a zero-carbon economy.Zn_(0.1)Cd_(0.9)S,a rod-like semiconductor metal sulfide,e...The process of utilizing solar-driven semiconductor water splitting for the production of hydrogen is a vital strategy in the pursuit of a zero-carbon economy.Zn_(0.1)Cd_(0.9)S,a rod-like semiconductor metal sulfide,encounters considerable difficulties stemming from the swift recombination of charge carriers generated by light.Overcoming the coulombic interactions between charge carriers is essential for achieving efficient separation.In this study,we modified Zn_(0.1)Cd_(0.9)S with dodecahedral rare-earth compound CeVO_(4) and employed ultrasonic self-assembly to tightly couple the two materials.This integration established a built-in electric field and constructed an S-scheme heterojunction.Within this configuration,Zn_(0.1)Cd_(0.9)S serves as an electron acceptor while CeVO_(4) functions as an electron donor.Driven by the built-in electric field,electrons rapidly traverse the tightly coupled interface,minimizing their path length.The S-scheme heterojunction preserves the catalyst's strong redox capabilities and facilitates the vectorial separation of photogenerated charge carriers.In situ irradiated X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses further validated the charge transfer mechanism of the S-scheme heterojunction.Density functional theory calculations elucidated the electronic states and roles of the catalyst,thereby establishing a theoretical framework for the investigation of S-scheme heterojunctions.This work lays a theoretical basis for the design and mechanistic investigation of S-scheme heterojunction catalysts.展开更多
Photoreforming poly(lactic acid)(PLA)plastics into pyruvic acid(PA)coupled with hydrogen evolution is of great significance for sustainable development.However,a significant challenge lies inα-OH bond cleaving of lac...Photoreforming poly(lactic acid)(PLA)plastics into pyruvic acid(PA)coupled with hydrogen evolution is of great significance for sustainable development.However,a significant challenge lies inα-OH bond cleaving of lactic acid(LA).Herein,CdS/Bi_(4)Ti_(3)O_(12)composite is fabricated,bridged by Bi−S bonds,through in-situ growth of CdS nanoparticles on Bi_(4)Ti_(3)O_(12)nanoflowers for the successive removal of hydrogen fromα-C in LA.In-situ X-ray photoelectron spectroscopy confirms the S-scheme carriers transfer route and interfacial Bi−S bond in CdS/Bi_(4)Ti_(3)O_(12).Consequently,the photo-electrons and holes with extended lifetimes and strong redox potential accumulate in the CdS conduction band and Bi_(4)Ti_(3)O_(12)valence band,respectively,as evidenced by in-situ electron spin resonance and time-resolved photoluminescence.This facilitates the generation of·OH radicals,which further participate in the successive dehydrogenation reaction of LA.Consequently,the photoreforming efficiencies of converting PLA into PA and H_(2)by CdS/Bi_(4)Ti_(3)O_(12)are 1.7 and 3.16 mmol g^(-1)h^(-1),which are respectively 2.8 and 22 times higher than that by pristine Bi_(4)Ti_(3)O_(12).The present work provides a new approach for designing S-scheme to achieve hydrogen production and value-added conversion of plastics.展开更多
Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt ...Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt oxyhydroxide @covalent organic frameworks(CoOOH@COFs) S-scheme heterojunction was synthesized,which combined the visible-light-driven photocatalysis and peroxymonosulfate(PMS) activation to synergistically generate abundant reactive oxygen species(ROSs) for TCS degradation.The degradation efficiency of TCS reached 100 % within 8 min in the Vis-CoOOH@COFs/PMS system,and the reaction rate constant was 0.456 min^(-1),which was nearly 1.90 and 2.85 times that of single Co OOH and COFs,and2.36 times that under dark condition,respectively.The density functional theory(DFT) calculations confirmed the energy band bending of CoOOH@COFs and S-scheme charge transport from COFs to Co OOH.Both experimental and theoretical analyses indicated that Co OOH@COFs in photocatalytic-PMS activation systems synergistically facilitated photo-generated carrier separation,enhanced interfacial electron transfer,accelerated PMS activation,and generated multiple ROSs.In particular,photogenerated electrons(e^(-))accelerated the Co(Ⅲ)/Co(Ⅱ) redox cycle,while the PMS captured the e-,which significantly decreased the charge combination of Co OOH@COFs.Radicals(O_(2)^(·-),^(·)OH,and SO_(4)^(·-)) and non-radicals(such as ^(1)O_(2),h^(+),and e^(-)) were both presented in the Vis-CoOOH@COFs/PMS system,with O_(2)^(-) playing a dominant role in TCS degradation.Furthermore,the pathway of TCS degradation and toxicity of intermediates were explored by DFT calculation and transformation product identification.Importantly,the environmentally friendly CoOOH@COFs S-scheme heterojunction exhibited excellent stability and reusability.In conclusion,this study innovatively designed an S-scheme heterojunction in the photocatalytic-PMS activation system,providing guidance and theoretical support for efficient and eco-friendly wastewater treatment.展开更多
The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS...The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.展开更多
Presented herein are the delicate design and synthesis of S-scheme NiTiO_(3)/CdS heterostructures composed of CdS nanoparticles anchored on the surface of NiTiO_(3) nanorods for photocatalytic CO_(2) reduction.Systema...Presented herein are the delicate design and synthesis of S-scheme NiTiO_(3)/CdS heterostructures composed of CdS nanoparticles anchored on the surface of NiTiO_(3) nanorods for photocatalytic CO_(2) reduction.Systematic physicochemical studies demonstrate that NiTiO_(3)/CdS hybrid empowers superior light absorption and enhanced CO_(2) capture and activation.Electron spin resonance validates that the charge carriers in NiTiO_(3)/CdS follow a S-scheme transfer pathway,which powerfully impedes their recombination and promotes their separation.Importantly,the photogenerated holes on CdS are effectively consumed at the hero-interface by the electron from NiTiO_(3),preventing the photo-corrosion of the metal sulfide.As a result,with Co(bpy)_(3)^(2+)as a cocatalyst,NiTiO_(3)/CdS displays a considerable performance for CO_(2) reduction,affording a high CO yield rate of 20.8µmol h^(−1).Moreover,the photocatalyst also manifests substantial stability and good reusability for repeated CO_(2) reaction cycles in the created tandem photochemical system.In addition,the possible CO_(2) photoreduction mechanism is constructed on the basis of the intermediates monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy.展开更多
S-scheme heterojunctions have gained widespread application in photocatalytic reactions due to their dis-tinctive carrier transport mechanism and remarkable redox capabilities.However,a significant challenge persists ...S-scheme heterojunctions have gained widespread application in photocatalytic reactions due to their dis-tinctive carrier transport mechanism and remarkable redox capabilities.However,a significant challenge persists in extending carrier lifetimes while simultaneously enhancing light absorption,both of which are essential for optimizing photocatalytic activity.Herein,we report the solvothermal synthesis of ul-trathin CdS nanosheets grown in situ on two-dimensional(2D)Ni-MOF to construct 2D/2D S-scheme heterojunctions.Comprehensive characterizations reveal that the incorporation of Ni-MOF(metal-organic framework)with ligand-to-metal charge transfer(LMCT)states not only broadens optical absorption but also significantly prolongs carrier lifetimes.This synergistic enhancement,coupled with the S-scheme charge transport mechanism,enables the composite to function as a bifunctional catalyst for photocat-alytic hydrogen production and simultaneous benzylamine coupling.The optimal system demonstrates an impressive hydrogen evolution rate of 8.5 mmol g^(-1) h^(-1) and an N-benzylidenebenzylamine yield of 4.6 mmol g^(-1) h^(-1) without requiring a cocatalyst.This work underscores the potential of integrating MOFs with LMCT states into S-scheme heterojunctions to enhance interfacial charge transfer,offering valuable insights for the design of S-scheme heterojunctions for artificial photosynthesis and related fields.展开更多
Inefficient photo-carrier separation and sluggish photoreaction dynamics appreciably undermine the photocatalytic decontamination efficacy of photocatalysts.Herein,an S-scheme Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)heterojunc...Inefficient photo-carrier separation and sluggish photoreaction dynamics appreciably undermine the photocatalytic decontamination efficacy of photocatalysts.Herein,an S-scheme Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)heterojunction with interfacial Mo-S chemical bond is designed as an efficient photocatalyst.In this integrated photosystem,Bi2MoO6 and Mn_(0.5)Cd_(0.5)S function as oxidation and reduction centers of Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)microspheres,respectively.Importantly,the unique charge transfer mechanism in the chemically bonded S-scheme heterojunction with Mo-S bond as atom-scale charge transport highway effectively inhibits the photocorrosion of Mn_(0.5)Cd_(0.5)S and the recombination of photo-generated electron-hole pairs,endowing Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)photocatalyst with excellent photocatalytic decontamination performance and stability.Besides,integration of Mn_(0.5)Cd_(0.5)S nanocrystals into Bi2MoO6 improves hydrophilicity,conducive to the photoreactions.Strikingly,compared with Mn_(0.5)Cd_(0.5)S and Bi2MoO6,the Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)unveils much augmented photoactivity in tetracycline eradication,among which Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)-2 possesses the highest activity with the rate constant up to 0.0323 min-1,prominently outperforming other counterparts.This research offers a chemical bonding engineering combining with S-scheme heterojunction strategy for constructing extraordinary photocatalysts for environmental purification.展开更多
Developing highly efficient and recyclable photocatalysts has been regarded as an attractive strategy to solve antibiotic contaminants.Herein,we designed and fabricated Cy-C_(3) N_(4)/TiO_(2) S-scheme heterojunction f...Developing highly efficient and recyclable photocatalysts has been regarded as an attractive strategy to solve antibiotic contaminants.Herein,we designed and fabricated Cy-C_(3) N_(4)/TiO_(2) S-scheme heterojunction film with boosted charge transfer and a highly hydrophilic surface.The as-prepared heterojunction exhibited outstanding removal efficiency on tetracyclines and fluoroquinolone antibiotics(more than 80% within 90 min).The removal rate of 300-Cy-C_(3) N_(4)/TiO_(2) on norfloxacin(NOR)was 2.12,and 1.59 times higher than that of pristine TiO_(2),C_(3) N_(4)/TiO_(2),respectively.The excellent photocatalytic performance of 300-Cy-C_(3) N_(4)/TiO_(2) was attributed to the highly hydrophilic surface and effective transfer and separation of carriers.Moreover,the NOR degradation pathways were proposed based on the results of density functional theory(DFT),and liquid chromatography-mass spectrometry.The toxicity assessment indicated the toxicity of intermediates can be remarkably alleviated.The DFT calculation and selective photo-deposition experiment demonstrated that an internal electric field was formed at the heterojunction interface,and the charge carriers migrated between Cy-C_(3) N_(4) and TiO_(2) following an S-scheme transfer pathway.This research not only provides a promising method for tracking charge distribution on thin-film heterojunction photocatalysts but also helps us to design high-efficiency,and recyclable heterojunctions to solve antibiotic contaminants.展开更多
Coatings of marine equipment inevitably suffer from physical or chemical damage in service,together with biofouling from microbial attachment,leading to a shorter service life of them.Herein,a multi-functional corrosi...Coatings of marine equipment inevitably suffer from physical or chemical damage in service,together with biofouling from microbial attachment,leading to a shorter service life of them.Herein,a multi-functional corrosion-resistant coating with efficient photothermal self-healing and anti-biofouling per-formance was designed by using CuO/g-C_(3)N_(4)(CuO/CN)S-scheme heterojunction filler in combination with polydimethylsiloxane(PDMS)as the coating matrix for achieving the effective protection of Q235 steel.The results of the electrochemical impedance spectroscopy(EIS)experiments indicate that the CuO/CN/PDMS composite coatings possessed excellent corrosion resistance,in which the impedance ra-dius of optimal CuO/CN-1/PDMS composite coating could still remain 3.49×10^(9)Ωcm^(2)after 60 d of immersion in seawater under sunlight irradiation.Meanwhile,the as-prepared CuO/CN/PDMS compos-ite coating not only can be rapidly heated up under the Xenon lamp illumination to achieve complete self-repair of scratches within 45 min,but also exhibited excellent antimicrobial effects in the antifouling experiments.This study opens a new avenue for the development of g-C_(3)N_(4)-based multifunctional coat-ings and provides guidance for the development of the next generation of intelligent protective coatings.展开更多
Solar-driven Fenton-like reactions are promising strategies for degrading pharmaceutical wastewater to address environmental challenges and antibiotic pollution.However,its efficacy is limited by suboptimal light abso...Solar-driven Fenton-like reactions are promising strategies for degrading pharmaceutical wastewater to address environmental challenges and antibiotic pollution.However,its efficacy is limited by suboptimal light absorption efficiency,rapid charge recombination,and inadequate interfacial charge transfer.In this study,an inorganic/organic S-scheme photo-Fenton system of pseudobrookite/carbon nitride(FTOCN)was synthesized via a hydrothermally coupled calcination process for the effective purification of tetracycline antibiotics under visible-light irradiation.The optimized FTOCN-2 heterostructure exhibits a significantly enhanced TC degradation capacity of 90%within 60 min.The rate constant of FTOCN-2 is 1.6 and 5.2 times greater than those of FTO and CN,respectively.Furthermore,FTOCN exhibits high antibacterial efficacy,highlighting its potential application in the purification of natural water.Measurements via a range of analytical techniques,including Kelvin probe force microscopy,density functional theory calculations,in situ X-ray photoelectron spectroscopy,and femtosecond transient absorption spectroscopy,corroborate the S-scheme mechanism.This study provides a novel perspective for the development of photo-Fenton systems with S-scheme heterojunctions for water purification.展开更多
Covalent organic framework(COF)-based heterojunction has emerged as a promising photocatalyst to-ward solar-to-fuel conversion.However,achieving high charge carrier separation efficiency and superior photocatalytic pe...Covalent organic framework(COF)-based heterojunction has emerged as a promising photocatalyst to-ward solar-to-fuel conversion.However,achieving high charge carrier separation efficiency and superior photocatalytic performance still remain a significant challenge.Herein,CYANO-COF was integrated with ZnIn_(2)S_(4)via a facile in-situ growth method,thus forming CYANO-COF/ZnIn_(2)S_(4)heterojunction.According to the in-situ light irradiation X-ray photoelectron spectroscopy(XPS)characterization and theoretical calculation,CYANO-COF/ZnIn_(2)S_(4)heterojunction was verified to adopt an S-scheme charge transfer mechanism capable of fast charge carrier transfer rate and strong redox ability.As a result,the optimized CYANOCOF/ZnIn_(2)S_(4)-7.5%exhibited a superior photocatalytic hydrogen production rate of 129.1 mmol g^(-1)h^(-1),which was 3.9 and 56 times higher than that of pristine CYANO-COF(33.2 mmol g^(-1)h^(-1))and ZnIn_(2)S_(4)(2.3 mmol g^(-1)h^(-1)),respectively,and the apparent quantum efficiency(AQE)at 420 nm was 20.5%.The study shed light on the great promising of COF-based organic/inorganic S-scheme heterojunction toward solar fuel generation.展开更多
We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dh...We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dha-COF@Nb_(2)C was fabricated via the in-situ solvothermal growth of Tph-Dha-COF nanostructures on amino-functionalized Nb_(2)C MXene nanoflakes(Nb_(2)C-NH_(2)).The integration of Nb_(2)C significantly extended the visible light absorption of Tph-Dha-COF into the near-infrared region for photocatalytic H_(2)O_(2) production.The Tph-Dha-COF@Nb_(2)C composite demonstrated efficient charge separation,rapid electron transfer,and enhanced oxygen adsorption.Consequently,the Tph-Dha-COF@Nb_(2)C heterojunction exhibited a high H_(2)O_(2) production rate of 1833μmol g^(-1) h^(-1) without sacrificial agents.In-situ Fourier transformed infrared spectroscopy and density functional theory calculations revealed the photocatalytic H_(2)O_(2) production mechanism.The generated H_(2)O_(2) demonstrated enhanced antibacterial activity.This work presents the first application of Nb_(2)C in the photocatalytic synthesis of H_(2)O_(2) and provides a novel strategy for constructing COF-based heterojunctions for photocatalytic H_(2)O_(2) generation and wastewater treatment.展开更多
The establishment of S-scheme heterojunctions has arisen as a promising strategy for the advancement of efficient photocatalytic systems with superior charge separation and redox ability,specifically for H_(2)O_(2)pro...The establishment of S-scheme heterojunctions has arisen as a promising strategy for the advancement of efficient photocatalytic systems with superior charge separation and redox ability,specifically for H_(2)O_(2)production.In this investigation,an innovative 2D/2D g-C_(3)N_(4)/BiOBr S-scheme heterojunction was meticulously engineered through an in situ growth methodology.The synthetic composites exhibit boosted H_(2)O_(2)production activity,achieving a peak generation rate of 392μmol L^(-1)h^(-1),approximately 8.7-fold and 2.1-fold increase over the pristine BiOBr and g-C_(3)N_(4),respectively.Such a superior activity should be attributed to the highly efficient charge separation and migration mechanisms,along with the sustained robust redox capability of S-scheme heterostructure,which are verified by time-resolved photoluminescence spectroscopy,photocurrent test and electron paramagnetic resonance measurements.Furthermore,the interfacial electric field induced S-scheme charge transfer mechanism between g-C_(3)N_(4)and BiOBr is systematically certificated by in situ irradiated X-ray photoelectron spectroscopy and density functional theory calculation.This research offers a comprehensive protocol for the systematic development and construction of highly efficient S-scheme heterojunction photocatalysts,specifically tailored for enhanced H_(2)O_(2)production.展开更多
Emerging contaminants in water sources present serious environmental and health risks,creating an urgent need for efficient and reliable treatment strategies.Photocatalytic advanced oxidation processes(AOPs)provide ra...Emerging contaminants in water sources present serious environmental and health risks,creating an urgent need for efficient and reliable treatment strategies.Photocatalytic advanced oxidation processes(AOPs)provide rapid reaction rates and strong oxidation capabilities,however,comprehensive evaluations of wastewater treatment,including degradation pathways,toxicity assessments and mechanistic insights,remain underexplored in the literature.This study presents novel S-scheme Mn_(0.5)Cd_(0.5)S/In_(2)S_(3)(MCS/IS)photocatalysts for efficient degradation of antibiotic pollutants,with a particular focus on tetracycline hydrochloride(TCH).The optimized MCS/IS photocatalyst demonstrates exceptional degradation efficiency and robust resistance to inorganic anions.Additionally,a continuous-flow wastewater treatment system,using an MCS/IS membrane,demonstrates outstanding stability in TCH photodegradation.Utilizing response surface methodology and Fukui function analysis,the effects of various parameters on photocatalytic degradation rates,along with the associated pathways and intermediate products,have been thoroughly investigated.Toxicity assessments confirm the environmental safety of the treated effluents.Mechanistic studies show that the S-scheme heterojunction in the MCS/IS photocatalyst improves electron-hole separation,thereby enhancing photocatalytic performance.It is expected that this study will serve as a model for advancing the removal of emerging contaminants,further enhancing photocatalytic AOPs as sustainable water purification technologies.展开更多
文摘The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.
文摘To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.
基金supported by the Inoue Enryo Memorial Grant of Toyo University(2023No.63)the He’nan Provincial Natural Science Foundation,China(No.252300420433)the Leading goose research and development plan of Zhejiang,China(No.2023C02039).
文摘To enhance the visible light response of titanium dioxide(TiO_(2)),titanium carbide(TiC)nanoparticles(NPs)were thermally treated in carbon powder,effectively overcoming the challenges associated with conventional doping methods.During the treatment,a TiO_(2)thin shell with oxygen vacancies(OVs)formed around the TiC NPs,creating a shell-core structure S-scheme photocatalyst.Transmission electron microscopy(TEM)and ultraviolet-visible(UV-vis)spectroscopy confirmed the successful formation of the TiO_(2)shell.By optimizing the shell thickness,the TiO_(2)-TiC shell-core structure achieved an ideal shell-core ratio,resulting in strong visible light absorption(400-800 nm),and the degradation rate constant of Rhodamine B(RhB)of sample cHT500 reached 0.0687 min^(−1),which is 20.8times higher than that of pristine TiO_(2)(0.0033 min^(−1))under visible-light irradiation.In addition,cytocompatibility tests showed that sample cHT500 exhibits favorable cell viability,which is comparable to that of TiO_(2)nanoparticles,and thus remarkably mitigates the poor biocompatibility inherent to TiC,making them promising candidates for biomedical and photocatalytic applications.
基金supported by the NSF of China(Nos.22579102 and 22405160)the Natural Science Foundation of Hubei Province(2024AFB288)+2 种基金the Natural Science Research Project of Yichang City(Grant A25-3-007)the 111 Project(D20015)the Key Project Foundation of Hubei Three Gorges Laboratory(SC250009)。
文摘Innovative S-scheme heterostructures face intrinsic limitations in charge separation due to insufficient interfacial driving forces.This work pioneers a dual-vacancy engineering strategy to break this bottleneck,constructing a plasmonic ZnIn_(2)S_(4-x)MoO_(3-x)(ZIS/MO)S-scheme heterojunction where oxygen and sulfur vacancies synergistically reconfigure charge transfer dynamics via dual-path modulation.Uniquely,sulfur vacancies amplify the built-in electric field(IEF)intensity by enlarging the Fermi level gap,while oxygen and sulfur dual-vacancies induce localized surface plasmon resonance(LSPR)via free-carrier concentration enhancement.Simultaneously,sulfur vacancies lower the H^(*)adsorption barrier,and dual vacancies amplify photothermal conversion by promoting nonradiative decay,accelerating temperature elevation and kinetics.Electron dynamics confirm that this dual-vacancy synergy prolongs charge carrier lifetime by a factor of 5.23.Consequently,the optimized sulfur vacancy-rich ZnIn_(2)S_(4-x)/MoO_(3-x)(R-ZIS/MO)exhibits remarkable photocatalytic hydrogen production rates of 3.60 mmol g^(-1) h^(-1)under visible light and 22.74 mmol g^(-1) h^(-1) under full-spectrum irradiation,representing 7.8-fold and17.2-fold enhancements,respectively.This study establishes a new paradigm.Targeted dual-vacancy coordination in plasmonic heterostructures enables unprecedented IEF-LSPR co-modulation,opening avenues for high-efficiency solar energy conversion.
基金Project supported by the National Natural Science Foundation of China(22271106,52073286)the Natural Science Foundation of Fujian Province(2006L2005)。
文摘The process of utilizing solar-driven semiconductor water splitting for the production of hydrogen is a vital strategy in the pursuit of a zero-carbon economy.Zn_(0.1)Cd_(0.9)S,a rod-like semiconductor metal sulfide,encounters considerable difficulties stemming from the swift recombination of charge carriers generated by light.Overcoming the coulombic interactions between charge carriers is essential for achieving efficient separation.In this study,we modified Zn_(0.1)Cd_(0.9)S with dodecahedral rare-earth compound CeVO_(4) and employed ultrasonic self-assembly to tightly couple the two materials.This integration established a built-in electric field and constructed an S-scheme heterojunction.Within this configuration,Zn_(0.1)Cd_(0.9)S serves as an electron acceptor while CeVO_(4) functions as an electron donor.Driven by the built-in electric field,electrons rapidly traverse the tightly coupled interface,minimizing their path length.The S-scheme heterojunction preserves the catalyst's strong redox capabilities and facilitates the vectorial separation of photogenerated charge carriers.In situ irradiated X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses further validated the charge transfer mechanism of the S-scheme heterojunction.Density functional theory calculations elucidated the electronic states and roles of the catalyst,thereby establishing a theoretical framework for the investigation of S-scheme heterojunctions.This work lays a theoretical basis for the design and mechanistic investigation of S-scheme heterojunction catalysts.
基金supported by the National Natural Science Foundation of China(Nos.52161145409,21976116)SAFEA of China("Belt and Road"Innovative Talent Exchange Foreign Expert Project No.2023041004L)+1 种基金(High-end Foreign Expert Project No.G2023041021L)Alexander-von-Humboldt Foundation of Germany(Group-Linkage Program).
文摘Photoreforming poly(lactic acid)(PLA)plastics into pyruvic acid(PA)coupled with hydrogen evolution is of great significance for sustainable development.However,a significant challenge lies inα-OH bond cleaving of lactic acid(LA).Herein,CdS/Bi_(4)Ti_(3)O_(12)composite is fabricated,bridged by Bi−S bonds,through in-situ growth of CdS nanoparticles on Bi_(4)Ti_(3)O_(12)nanoflowers for the successive removal of hydrogen fromα-C in LA.In-situ X-ray photoelectron spectroscopy confirms the S-scheme carriers transfer route and interfacial Bi−S bond in CdS/Bi_(4)Ti_(3)O_(12).Consequently,the photo-electrons and holes with extended lifetimes and strong redox potential accumulate in the CdS conduction band and Bi_(4)Ti_(3)O_(12)valence band,respectively,as evidenced by in-situ electron spin resonance and time-resolved photoluminescence.This facilitates the generation of·OH radicals,which further participate in the successive dehydrogenation reaction of LA.Consequently,the photoreforming efficiencies of converting PLA into PA and H_(2)by CdS/Bi_(4)Ti_(3)O_(12)are 1.7 and 3.16 mmol g^(-1)h^(-1),which are respectively 2.8 and 22 times higher than that by pristine Bi_(4)Ti_(3)O_(12).The present work provides a new approach for designing S-scheme to achieve hydrogen production and value-added conversion of plastics.
文摘Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt oxyhydroxide @covalent organic frameworks(CoOOH@COFs) S-scheme heterojunction was synthesized,which combined the visible-light-driven photocatalysis and peroxymonosulfate(PMS) activation to synergistically generate abundant reactive oxygen species(ROSs) for TCS degradation.The degradation efficiency of TCS reached 100 % within 8 min in the Vis-CoOOH@COFs/PMS system,and the reaction rate constant was 0.456 min^(-1),which was nearly 1.90 and 2.85 times that of single Co OOH and COFs,and2.36 times that under dark condition,respectively.The density functional theory(DFT) calculations confirmed the energy band bending of CoOOH@COFs and S-scheme charge transport from COFs to Co OOH.Both experimental and theoretical analyses indicated that Co OOH@COFs in photocatalytic-PMS activation systems synergistically facilitated photo-generated carrier separation,enhanced interfacial electron transfer,accelerated PMS activation,and generated multiple ROSs.In particular,photogenerated electrons(e^(-))accelerated the Co(Ⅲ)/Co(Ⅱ) redox cycle,while the PMS captured the e-,which significantly decreased the charge combination of Co OOH@COFs.Radicals(O_(2)^(·-),^(·)OH,and SO_(4)^(·-)) and non-radicals(such as ^(1)O_(2),h^(+),and e^(-)) were both presented in the Vis-CoOOH@COFs/PMS system,with O_(2)^(-) playing a dominant role in TCS degradation.Furthermore,the pathway of TCS degradation and toxicity of intermediates were explored by DFT calculation and transformation product identification.Importantly,the environmentally friendly CoOOH@COFs S-scheme heterojunction exhibited excellent stability and reusability.In conclusion,this study innovatively designed an S-scheme heterojunction in the photocatalytic-PMS activation system,providing guidance and theoretical support for efficient and eco-friendly wastewater treatment.
文摘The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.22372035,22302039,22311540011,and 21973014)the“111 Project”(No.D16008).
文摘Presented herein are the delicate design and synthesis of S-scheme NiTiO_(3)/CdS heterostructures composed of CdS nanoparticles anchored on the surface of NiTiO_(3) nanorods for photocatalytic CO_(2) reduction.Systematic physicochemical studies demonstrate that NiTiO_(3)/CdS hybrid empowers superior light absorption and enhanced CO_(2) capture and activation.Electron spin resonance validates that the charge carriers in NiTiO_(3)/CdS follow a S-scheme transfer pathway,which powerfully impedes their recombination and promotes their separation.Importantly,the photogenerated holes on CdS are effectively consumed at the hero-interface by the electron from NiTiO_(3),preventing the photo-corrosion of the metal sulfide.As a result,with Co(bpy)_(3)^(2+)as a cocatalyst,NiTiO_(3)/CdS displays a considerable performance for CO_(2) reduction,affording a high CO yield rate of 20.8µmol h^(−1).Moreover,the photocatalyst also manifests substantial stability and good reusability for repeated CO_(2) reaction cycles in the created tandem photochemical system.In addition,the possible CO_(2) photoreduction mechanism is constructed on the basis of the intermediates monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy.
基金financially supported by the National Key Re-search and Development Program of China(Nos.2022YFB3803600 and 2022YFE0115900)the National Natural Science Foundation of China(Nos.U24A2071,22278324,22238009,22361142704,22202187,and U23A20102)+1 种基金the National Science Foundation of Hubei Province of China(No.2022CFA001)Key R&D Program Projects in Hubei Province(No.2023BAB113).
文摘S-scheme heterojunctions have gained widespread application in photocatalytic reactions due to their dis-tinctive carrier transport mechanism and remarkable redox capabilities.However,a significant challenge persists in extending carrier lifetimes while simultaneously enhancing light absorption,both of which are essential for optimizing photocatalytic activity.Herein,we report the solvothermal synthesis of ul-trathin CdS nanosheets grown in situ on two-dimensional(2D)Ni-MOF to construct 2D/2D S-scheme heterojunctions.Comprehensive characterizations reveal that the incorporation of Ni-MOF(metal-organic framework)with ligand-to-metal charge transfer(LMCT)states not only broadens optical absorption but also significantly prolongs carrier lifetimes.This synergistic enhancement,coupled with the S-scheme charge transport mechanism,enables the composite to function as a bifunctional catalyst for photocat-alytic hydrogen production and simultaneous benzylamine coupling.The optimal system demonstrates an impressive hydrogen evolution rate of 8.5 mmol g^(-1) h^(-1) and an N-benzylidenebenzylamine yield of 4.6 mmol g^(-1) h^(-1) without requiring a cocatalyst.This work underscores the potential of integrating MOFs with LMCT states into S-scheme heterojunctions to enhance interfacial charge transfer,offering valuable insights for the design of S-scheme heterojunctions for artificial photosynthesis and related fields.
文摘Inefficient photo-carrier separation and sluggish photoreaction dynamics appreciably undermine the photocatalytic decontamination efficacy of photocatalysts.Herein,an S-scheme Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)heterojunction with interfacial Mo-S chemical bond is designed as an efficient photocatalyst.In this integrated photosystem,Bi2MoO6 and Mn_(0.5)Cd_(0.5)S function as oxidation and reduction centers of Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)microspheres,respectively.Importantly,the unique charge transfer mechanism in the chemically bonded S-scheme heterojunction with Mo-S bond as atom-scale charge transport highway effectively inhibits the photocorrosion of Mn_(0.5)Cd_(0.5)S and the recombination of photo-generated electron-hole pairs,endowing Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)photocatalyst with excellent photocatalytic decontamination performance and stability.Besides,integration of Mn_(0.5)Cd_(0.5)S nanocrystals into Bi2MoO6 improves hydrophilicity,conducive to the photoreactions.Strikingly,compared with Mn_(0.5)Cd_(0.5)S and Bi2MoO6,the Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)unveils much augmented photoactivity in tetracycline eradication,among which Mn_(0.5)Cd_(0.5)S/Bi_(2)MoO_(6)-2 possesses the highest activity with the rate constant up to 0.0323 min-1,prominently outperforming other counterparts.This research offers a chemical bonding engineering combining with S-scheme heterojunction strategy for constructing extraordinary photocatalysts for environmental purification.
基金funded by the National Natural Science Foundation of China(Nos.51772003 and 51701001)the Excellent Research and Innovation Team Project of Anhui Province(No.2023AH010077)the Key Research and Development Projects in Anhui Province(No.202004b11020021).
文摘Developing highly efficient and recyclable photocatalysts has been regarded as an attractive strategy to solve antibiotic contaminants.Herein,we designed and fabricated Cy-C_(3) N_(4)/TiO_(2) S-scheme heterojunction film with boosted charge transfer and a highly hydrophilic surface.The as-prepared heterojunction exhibited outstanding removal efficiency on tetracyclines and fluoroquinolone antibiotics(more than 80% within 90 min).The removal rate of 300-Cy-C_(3) N_(4)/TiO_(2) on norfloxacin(NOR)was 2.12,and 1.59 times higher than that of pristine TiO_(2),C_(3) N_(4)/TiO_(2),respectively.The excellent photocatalytic performance of 300-Cy-C_(3) N_(4)/TiO_(2) was attributed to the highly hydrophilic surface and effective transfer and separation of carriers.Moreover,the NOR degradation pathways were proposed based on the results of density functional theory(DFT),and liquid chromatography-mass spectrometry.The toxicity assessment indicated the toxicity of intermediates can be remarkably alleviated.The DFT calculation and selective photo-deposition experiment demonstrated that an internal electric field was formed at the heterojunction interface,and the charge carriers migrated between Cy-C_(3) N_(4) and TiO_(2) following an S-scheme transfer pathway.This research not only provides a promising method for tracking charge distribution on thin-film heterojunction photocatalysts but also helps us to design high-efficiency,and recyclable heterojunctions to solve antibiotic contaminants.
基金supported by the National Natural Science Foundation of China(Nos.22006057 and 21906072)the China Postdoctoral Science Foundation(No.2023M743178)+2 种基金the Jiangsu Province Industry-University-Research Cooperation Project(No.BY20231482)the Open Fund of the Key Laboratory of Solar Cell electrode Materials in China Petroleum,Chemical Industry(No.2024A093)the Key Laboratory of Functional Inorganic Mate-rial Chemistry(Heilongjiang University),Ministry of Education and Postgraduate Research&Practice Innovation Program of Jiangsu Province(China)(No.SJCX24_2481).
文摘Coatings of marine equipment inevitably suffer from physical or chemical damage in service,together with biofouling from microbial attachment,leading to a shorter service life of them.Herein,a multi-functional corrosion-resistant coating with efficient photothermal self-healing and anti-biofouling per-formance was designed by using CuO/g-C_(3)N_(4)(CuO/CN)S-scheme heterojunction filler in combination with polydimethylsiloxane(PDMS)as the coating matrix for achieving the effective protection of Q235 steel.The results of the electrochemical impedance spectroscopy(EIS)experiments indicate that the CuO/CN/PDMS composite coatings possessed excellent corrosion resistance,in which the impedance ra-dius of optimal CuO/CN-1/PDMS composite coating could still remain 3.49×10^(9)Ωcm^(2)after 60 d of immersion in seawater under sunlight irradiation.Meanwhile,the as-prepared CuO/CN/PDMS compos-ite coating not only can be rapidly heated up under the Xenon lamp illumination to achieve complete self-repair of scratches within 45 min,but also exhibited excellent antimicrobial effects in the antifouling experiments.This study opens a new avenue for the development of g-C_(3)N_(4)-based multifunctional coat-ings and provides guidance for the development of the next generation of intelligent protective coatings.
文摘Solar-driven Fenton-like reactions are promising strategies for degrading pharmaceutical wastewater to address environmental challenges and antibiotic pollution.However,its efficacy is limited by suboptimal light absorption efficiency,rapid charge recombination,and inadequate interfacial charge transfer.In this study,an inorganic/organic S-scheme photo-Fenton system of pseudobrookite/carbon nitride(FTOCN)was synthesized via a hydrothermally coupled calcination process for the effective purification of tetracycline antibiotics under visible-light irradiation.The optimized FTOCN-2 heterostructure exhibits a significantly enhanced TC degradation capacity of 90%within 60 min.The rate constant of FTOCN-2 is 1.6 and 5.2 times greater than those of FTO and CN,respectively.Furthermore,FTOCN exhibits high antibacterial efficacy,highlighting its potential application in the purification of natural water.Measurements via a range of analytical techniques,including Kelvin probe force microscopy,density functional theory calculations,in situ X-ray photoelectron spectroscopy,and femtosecond transient absorption spectroscopy,corroborate the S-scheme mechanism.This study provides a novel perspective for the development of photo-Fenton systems with S-scheme heterojunctions for water purification.
基金financially supported by the National Natural Science Foundation of China(Nos.22478306,52073263,22376217,and 21905209).
文摘Covalent organic framework(COF)-based heterojunction has emerged as a promising photocatalyst to-ward solar-to-fuel conversion.However,achieving high charge carrier separation efficiency and superior photocatalytic performance still remain a significant challenge.Herein,CYANO-COF was integrated with ZnIn_(2)S_(4)via a facile in-situ growth method,thus forming CYANO-COF/ZnIn_(2)S_(4)heterojunction.According to the in-situ light irradiation X-ray photoelectron spectroscopy(XPS)characterization and theoretical calculation,CYANO-COF/ZnIn_(2)S_(4)heterojunction was verified to adopt an S-scheme charge transfer mechanism capable of fast charge carrier transfer rate and strong redox ability.As a result,the optimized CYANOCOF/ZnIn_(2)S_(4)-7.5%exhibited a superior photocatalytic hydrogen production rate of 129.1 mmol g^(-1)h^(-1),which was 3.9 and 56 times higher than that of pristine CYANO-COF(33.2 mmol g^(-1)h^(-1))and ZnIn_(2)S_(4)(2.3 mmol g^(-1)h^(-1)),respectively,and the apparent quantum efficiency(AQE)at 420 nm was 20.5%.The study shed light on the great promising of COF-based organic/inorganic S-scheme heterojunction toward solar fuel generation.
文摘We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dha-COF@Nb_(2)C was fabricated via the in-situ solvothermal growth of Tph-Dha-COF nanostructures on amino-functionalized Nb_(2)C MXene nanoflakes(Nb_(2)C-NH_(2)).The integration of Nb_(2)C significantly extended the visible light absorption of Tph-Dha-COF into the near-infrared region for photocatalytic H_(2)O_(2) production.The Tph-Dha-COF@Nb_(2)C composite demonstrated efficient charge separation,rapid electron transfer,and enhanced oxygen adsorption.Consequently,the Tph-Dha-COF@Nb_(2)C heterojunction exhibited a high H_(2)O_(2) production rate of 1833μmol g^(-1) h^(-1) without sacrificial agents.In-situ Fourier transformed infrared spectroscopy and density functional theory calculations revealed the photocatalytic H_(2)O_(2) production mechanism.The generated H_(2)O_(2) demonstrated enhanced antibacterial activity.This work presents the first application of Nb_(2)C in the photocatalytic synthesis of H_(2)O_(2) and provides a novel strategy for constructing COF-based heterojunctions for photocatalytic H_(2)O_(2) generation and wastewater treatment.
文摘The establishment of S-scheme heterojunctions has arisen as a promising strategy for the advancement of efficient photocatalytic systems with superior charge separation and redox ability,specifically for H_(2)O_(2)production.In this investigation,an innovative 2D/2D g-C_(3)N_(4)/BiOBr S-scheme heterojunction was meticulously engineered through an in situ growth methodology.The synthetic composites exhibit boosted H_(2)O_(2)production activity,achieving a peak generation rate of 392μmol L^(-1)h^(-1),approximately 8.7-fold and 2.1-fold increase over the pristine BiOBr and g-C_(3)N_(4),respectively.Such a superior activity should be attributed to the highly efficient charge separation and migration mechanisms,along with the sustained robust redox capability of S-scheme heterostructure,which are verified by time-resolved photoluminescence spectroscopy,photocurrent test and electron paramagnetic resonance measurements.Furthermore,the interfacial electric field induced S-scheme charge transfer mechanism between g-C_(3)N_(4)and BiOBr is systematically certificated by in situ irradiated X-ray photoelectron spectroscopy and density functional theory calculation.This research offers a comprehensive protocol for the systematic development and construction of highly efficient S-scheme heterojunction photocatalysts,specifically tailored for enhanced H_(2)O_(2)production.
文摘Emerging contaminants in water sources present serious environmental and health risks,creating an urgent need for efficient and reliable treatment strategies.Photocatalytic advanced oxidation processes(AOPs)provide rapid reaction rates and strong oxidation capabilities,however,comprehensive evaluations of wastewater treatment,including degradation pathways,toxicity assessments and mechanistic insights,remain underexplored in the literature.This study presents novel S-scheme Mn_(0.5)Cd_(0.5)S/In_(2)S_(3)(MCS/IS)photocatalysts for efficient degradation of antibiotic pollutants,with a particular focus on tetracycline hydrochloride(TCH).The optimized MCS/IS photocatalyst demonstrates exceptional degradation efficiency and robust resistance to inorganic anions.Additionally,a continuous-flow wastewater treatment system,using an MCS/IS membrane,demonstrates outstanding stability in TCH photodegradation.Utilizing response surface methodology and Fukui function analysis,the effects of various parameters on photocatalytic degradation rates,along with the associated pathways and intermediate products,have been thoroughly investigated.Toxicity assessments confirm the environmental safety of the treated effluents.Mechanistic studies show that the S-scheme heterojunction in the MCS/IS photocatalyst improves electron-hole separation,thereby enhancing photocatalytic performance.It is expected that this study will serve as a model for advancing the removal of emerging contaminants,further enhancing photocatalytic AOPs as sustainable water purification technologies.
