Recent interest in photocatalytic water splitting has intensified the demand in the development of photocatalysts capable of harnessing the full solar-spectrum.This study introduces a novel WO_(x)/ZnIn_(2)S_(4)Zscheme...Recent interest in photocatalytic water splitting has intensified the demand in the development of photocatalysts capable of harnessing the full solar-spectrum.This study introduces a novel WO_(x)/ZnIn_(2)S_(4)Zscheme heterojunction,prepared by depositing ZnIn_(2)S_(4)(ZIS)nanosheets onto WO_(x)nanorods,enabling efficient photothermal-coupled photocatalytic H_(2)evolution.The success relies on the engineered oxygen vacancies within WO_(x)nanorods,which not only confer excellent photothermal properties lowering the reaction barrier but also create defect levels in WO_(x)facilitating Z-scheme electron transfer from these levels to the valence band of ZIS.Consequently,the optimized WO_(x)/ZIS heterojunction exhibits a remarkable H_(2)evolution rate of 33.91 mmol h^(-1)g^(-1)with an apparent quantum efficiency of 23.6%at 400 nm.This study provides a new strategy for developing efficient Z-scheme heterojunctions with broadspectrum solar hydrogen production capabilities.展开更多
The oxysulfide La3NbS2O5 was synthesized by sulfurization using H2S and characterized by X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy （DRS） and field emission scanning electron microscopy （FE-...The oxysulfide La3NbS2O5 was synthesized by sulfurization using H2S and characterized by X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy （DRS） and field emission scanning electron microscopy （FE-SEM）. The relationship between the sulfurization conditions and the photocatalytic activities for H2 evolution was investigated. Sulfurization method allowed for synthesis of La3NbS2O5 at much lower temperatures and significantly shortened reaction time of 1 h compared with conventional solid-state techniques. The particle morphologies were regular platelike with sizes of 0.1-0.6μm and smooth surfaces. The highest activity for H2 evolution was obtained at 1073 K for 1 h, which was about 1.83 times that of La3NbS2O5 prepared by solid-state method.展开更多
Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D...Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D CdS/MoO3‒x heterojunction has been synthesized by the growth of 0D CdS nanoparticles on 2D plasmonic MoO3‒x elliptical nanosheets via a simple coprecipitation method.Taking advantage of the LSPR effect of the MoO3‒x elliptical nanosheets,the light absorption of the CdS/MoO3‒x heterojunction was extended from 600 nm to the near-infrared region(1400 nm).Furthermore,the introduction of 2D plasmonic MoO3‒x elliptical nanosheets not only provided a platform for the growth of CdS nanoparticles,but also contributed to the construction of an LSPR-enhanced S-scheme structure due to the interface between the MoO3‒x and CdS,accelerating the separation of light-induced electrons and holes.Therefore,the CdS/MoO3‒x heterojunction exhibited higher photocatalytic H2 generation activity than pristine CdS under visible light irradiation,including under 420,450,550,and 650 nm monochromic light,as well as improved photo-corrosion performance.展开更多
Willow branch-shaped MoS2/CdS heterojunctions are successfully synthesized for the first time by a facile one-pot hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, X-ray photoelectr...Willow branch-shaped MoS2/CdS heterojunctions are successfully synthesized for the first time by a facile one-pot hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption measurements, diffuse reflectance spectroscopy, and photoelectrochemical and photoluminescence spectroscopy tests. The photocatalytic hydrogen evolution activities of the samples were evaluated under visible light irradiation. The resulting MoS2/CdS heterojunctions exhibit a much improved photocatalytic hydrogen evolution activity than that obtained with CdS and MoS2. In particular, the optimized MC-5 (5 at.% MoS2/CdS) photocatalyst achieved the highest hydrogen production rate of 250.8 μmol h–1, which is 28 times higher than that of pristine CdS. The apparent quantum efficiency (AQE) at 420 nm was 3.66%. Further detailed characterizations revealed that the enhanced photocatalytic activity of the MoS2/CdS heterojunctions could be attributed to the efficient transfer and separation of photogenerated charge carriers resulting from the core-shell structure and the close contact between MoS2 nanosheets and CdS single-crystal nanorods, as well as to increased visible light absorption. A tentative mechanism for photocatalytic H2 evolution by MoS2/CdS heterojunctions was proposed. This work will open up new opportunities for developing more efficient photocatalysts for water splitting.展开更多
This review focused on rare-earth elements containing inorganic semiconductor photocatalysts for efficient solar energy conversion. We also summarized the recent progress in the modification of the transition metal ox...This review focused on rare-earth elements containing inorganic semiconductor photocatalysts for efficient solar energy conversion. We also summarized the recent progress in the modification of the transition metal oxides and mixed oxides with rare earth ions. In the first section, we surveyed a variety of rare-earth elements modified TiO2 photocatalysts. Attributed to the modifica-tion with rare-earth elements, phase transformation of TiO2 from anatase to rutile was inhibited. Furthermore, the light-absorbing property of the TiO2 modified with rare-earth elements was also enhanced. In the second section, we summarized the effects of rare-earth elements on the modification of transition metal mixed oxides. It was believed that the corner-shared octahedral units in the form of networks, chains and slabs within the mixed oxide lattice were essential for the enhancement of the photocatalytic activity. In the last section, the strategy for the design of NIR or IR response upconversion composite photocatalysts was also discussed.展开更多
Converting solar energy into clean and sustainable chemical fuels is a promising strategy for exploiting renewable energy.The application of photocatalytic water splitting technology in hydrogen production is importan...Converting solar energy into clean and sustainable chemical fuels is a promising strategy for exploiting renewable energy.The application of photocatalytic water splitting technology in hydrogen production is important for sustainable energy development and environmental protection.In this study,for the first time,2D Cu7S4 co-catalysts were coupled on the surface of a CdS nanosheet photocatalyst by a one-step ultrasonic-assisted electrostatic self-assembly method at room temperature.The as-fabricated 2D^-2D CdS/Cu7S4 layered heterojunctions were demonstrated to be advanced composite photocatalysts that enhance the water splitting efficiency toward hydrogen production.The highest hydrogen evolution rate of the 2D^-2D CdS/2%Cu7S4 binary heterojunction photocatalyst was up to 27.8 mmol g^-1 h^-1 under visible light irradiation,with an apparent quantum efficiency of 14.7%at 420 nm,which was almost 10.69 times and 2.65 times higher than those of pure CdS nanosheets(2.6 mmol g^-1 h^-1)and CdS-2%CuS(10.5 mmol g^-1 h^-1),respectively.The establishment of the CdS/Cu7S4 binary-layered heterojunction could not only enhance the separation of photogenerated electron-hole(e--h+)pairs,improve the transfer of photo-excited electrons,and prolong the life-span of photo-generated electrons,but also enhance the light absorption and hydrogen-evolution kinetics.All these factors are important for the enhancement of the photocatalytic activity.Expectedly,the 2D^-2D interface coupling strategy based on CdS NSs can be extensively exploited to improve the hydrogen-evolution activity over various kinds of conventional semiconductor NSs.展开更多
The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts...The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.展开更多
Porous C‐I codoped carbon nitride materials were synthesized by in‐situ codoping with iodized ionic liquid followed by post‐thermal treatment in air.The effects of doping content of C‐I codoping with different amo...Porous C‐I codoped carbon nitride materials were synthesized by in‐situ codoping with iodized ionic liquid followed by post‐thermal treatment in air.The effects of doping content of C‐I codoping with different amounts of ionic liquid on the structural,optical and photocatalytic properties of the samples were investigated.Characterization results show that more compact interlayer sacking can be achieved by post‐thermal treatment.Combined with C‐I codoping by insertion of ionic liquids,much enlarged surface area but optimized sp2 conjugated heterocyclic structure can be found in the catalysts.Optical and energy band analysis results evidence that the light absorptions especially in visible light region are significantly improved.Although the band gap of porous C‐I codoped samples enlarge because of the generation of porous,the negatively shifted conduction band position thermodynamically supplies stronger motivation for water reduction.Photoelectricity tests reveal that the photo‐induced electron density was increased after C‐I codoping modification.Also,the recombination rate of electron‐hole pairs is remarkably inhibited.The catalysts with moderate C‐I codoing content perform sharply enhanced photocatalytic H2 evolution activity under visible light irradiation.A H2 evolution rate of 168.2μmol/h was achieved and it was more than 9.8 times higher than pristine carbon nitride.This study demonstrates a novel non‐metal doping strategy for synthesis and optimization of polymer semiconductor with gratifying photocatalytic H2 evolution performance from water hydrolysis.展开更多
The development of efficient photocatalytic H2-evolution materials requires both rapid electron transfer and an effective interfacial catalysis reaction for H2 production. In addition to the well-known noble metals, l...The development of efficient photocatalytic H2-evolution materials requires both rapid electron transfer and an effective interfacial catalysis reaction for H2 production. In addition to the well-known noble metals, low-cost and earth-abundant non-noble metals can also act as electron- transfer mediators to modify photocatalysts. However, as almost all non-noble metals lack the interfacial catalytic active sites required for the H2-evolution reaction, the enhancement of the photocatalytic performance is limited. Therefore, the development of new interfacial active sites on metal-modified photocatalysts is of considerable importance. In this study, to enhance the photocatalytic evolution of H2 by Ni-modified TiO2, the formation of NiSx as interfacial active sites was promoted on the surface of Ni nanoparticles. Specifically, the co-modified TiO2/Ni-NiSx photocatalysts were prepared via a two-step process involving the photoinduced deposition of Ni on the TiO2 surface and the subsequent formation of NiSx on the Ni surface by a hydrothermal reaction method. It was found that the TiO2/Ni-NiSx photocatalysts exhibited enhanced photocatalytic H2-evolution activity. In particular, TiO2/Ni-NiSx(30%) showed the highest photocatalytic rate (223.74 μmol h.1), which was greater than those of TiO2, TiO2/Ni, and TiO2/NiSx by factors of 22.2, 8.0, and 2.2, respectively. The improved H2-evolution performance of TiO2/Ni-NiSx could be attributed to the excellent synergistic effect of Ni and NiSx, where Ni nanoparticles function as effective mediators to transfer electrons from the TiO2 surface and NiSx serves as interfacial active sites to capture H+ ions from solution and promote the interfacial H2-evolution reaction. The synergistic effect of the non-noble metal cocatalyst and the interfacial active sites may provide new insights for the design of highly efficient photocatalytic materials.展开更多
PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution o...PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution of the g-C3N4 nanosheets shows that it was significantly enhanced when PtPd alloy NPs were introduced as a co-catalyst. The 0.2 wt% PtPd/g-C3N4 composite photocatalyst gave a maximum H2 production rate of 1600.8 μmol g^–1 h^–1. Furthermore, when K2HPO4 was added to the reaction system, the H2 production rate increased to 2885.0 μmol g^–1 h^–1. The PtPd/g-C3N4 photocatalyst showed satisfactory photocatalytic stability and was able to maintain most of its photocatalytic activity after four experimental photocatalytic cycles. In addition, a possible mechanism for the enhanced photocatalytic activity was proposed and verified by various photoelectric techniques. These results demonstrate that the synergistic effect between PtPd and g-C3N4 helps to greatly improve the photocatalytic activity of the composite photocatalyst.展开更多
The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing r...The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing robust bifunctional electrocatalysts are of great significance. Herein, a hierarchical heteronanostructure with Ni–Co layered double hydroxide(LDH) ultrathin nanosheets coated on cobalt phosphide nanosheets arrays(CoxP@NiCo-LDH) are fabricated and used for co-electrolysis of methanol/water to co-produce value-added formate and hydrogen with saving energy. Benefiting from the fast charge transfer introduced by phosphide nanoarrays, the synergy in nanosheets catalysts with hetero-interface,CoxP@NiCo-LDH/Ni foam(NF) exhibits superior electrocatalytic performance(10 mA cm-2@ 1.24 V and-0.10 V for methanol selective oxidation and hydrogen evolution reaction, respectively). Furthermore,CoxP@NiCo-LDH/NF-based symmetric two-electrode electrolyzer drives a current density of 10 m A cm-2 with a low cell voltage of only 1.43 V and the Faradaic efficiency towards the generation of formate and H2 are close to 100% in the tested range of current density(from 40 to 200 m A cm-2). This work highlights the positive effect of hetero-interaction in the design of more efficient eletrocatalysts and might guide the way towards facile upgrading of alcohols and energy-saving electrolytic H2 co-generation.展开更多
In recent years,ternary heterostructures(HSs)composed of three semiconductors have attracted significant attention because of the effective separation and transfer of photogenerated electrons and holes in these materi...In recent years,ternary heterostructures(HSs)composed of three semiconductors have attracted significant attention because of the effective separation and transfer of photogenerated electrons and holes in these materials.In this work,new ternary Cd S/Zn S/Zn O(CZZ)HSs with one-dimensional(1D)nanofiber morphology have been successfully fabricated for the first time by a series of processes:electrospinning Zn O nanofibers,sulfurizing Zn O in situ to form Zn S/Zn O binary HSs,and depositing Cd S quantum dots in situ on the Zn S/Zn O HSs.Benefiting from the efficient separation and transfer of photoinduced charge carriers,the optimized CZZ ternary HSs exhibit a hydrogen evolution rate of 51.45 mmol h^-1 g^-1(quantum efficiency:26.88%at 420 nm)without any co-catalyst,which is 93.54 and 2.28 times higher than those exhibited by pristine Zn O and Zn S/Zn O binary HSs,respectively,under the same conditions.Furthermore,the rate of hydrogen evolution over the 1D CZZ nanofibers is significantly higher than that over 2D CZZ nanosheets(27.25 mmol h^-1 g^-1,in the presence of a Pt co-catalyst)prepared by the same sulfurization and deposition procedures.This can be ascribed to the significantly smaller geometric sizes of 1D nanofibers compared to those of 2D nanosheets,resulting in effectively suppressed recombination of photogenerated charge carriers and promotion of photocatalytic H2 evolution performance.展开更多
Construction of multi-channels of photo-carrier migration in photocatalysts is favor to boost conversion efficiency of solar energy by promoting the charge separation and transfer.Herein,a ternary ZnIn_(2)S_(4)/g-C_(3...Construction of multi-channels of photo-carrier migration in photocatalysts is favor to boost conversion efficiency of solar energy by promoting the charge separation and transfer.Herein,a ternary ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene hybrid composed of S-scheme junction integrated Schottky-junction was fabricated using a simple hydrothermal approach.All the components(g-C_(3)N_(4),ZnIn_(2)S_(4) and Ti_(3)C_(2) MXene)demonstrated two-dimensional(2D)nanosheets structure,leading to the formation of a 2D/2D/2D sandwich-like structure with intimate large interface for carrier migration.Furthermore,the photogenerated carriers on the g-C_(3)N_(4) possessed dual transfer channels,including one route in S-scheme transfer mode between the g-C_(3)N_(4) and ZnIn_(2)S_(4) and the other route in Schottky-junction between g-C_(3)N_(4) and Ti_(3)C_(2) MXene.Consequently,a highly efficient carrier separation and transport was realized in the ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene heterojunction.This ternary sample exhibited wide light response from 200 to 1400 nm and excellent photocatalytic H_(2) evolution of 2452.1μmol∙g^(–1)∙h^(–1),which was 200,3,1.5 and 1.6 times of g-C_(3)N_(4),ZnIn_(2)S_(4),ZnIn_(2)S_(4)/Ti_(3)C_(2) MXene and g-C_(3)N_(4)/ZnIn_(2)S_(4) binary composites.This work offers a paradigm for the rational construction of multi-electron pathways to regulate the charge separation and migration via the introduction of dual-junctions in catalytic system.展开更多
Developing highly active catalysts for photo/electrocatalytic water splitting is an attractive strategy to produce H2 as a renewable energy source.In this study,a new nickel boron oxide/graphdiyne(NiBi/GDY)hybrid cata...Developing highly active catalysts for photo/electrocatalytic water splitting is an attractive strategy to produce H2 as a renewable energy source.In this study,a new nickel boron oxide/graphdiyne(NiBi/GDY)hybrid catalyst was prepared by a facile synthetic approach.Benefitting from the strong electron donating ability of graphdiyne,NiBi/GDY showed an optimized electronic structure containing lower valence nickel atoms and demonstrated improved catalytic performance.As expected,NiBi/GDY displayed a high photocatalytic H2 evolution rate of 4.54 mmol g^(-1)h^(-1),2.9 and 4.5 times higher than those of NiBi/graphene and NiBi,respectively.NiBi/GDY also displayed outstanding electrocatalytic H2 evolution activity in 1.0 M KOH solution,with a current density of 400 mA/cm^(2)at an overpotential of 478.0 mV,which is lower than that of commercial Pt/C(505.3 mV@400 mA/cm^(2)).This work demonstrates that GDY is an ideal support for the development of highly active catalysts for photo/electrocatalytic H2 evolution.展开更多
ABSTRACT Rationally designing broad-spectrum photocatalysts to harvest whole visible-light region photons and enhance solar energy conversion is a“holy grail”for researchers,but is still a challenging issue.Herein,b...ABSTRACT Rationally designing broad-spectrum photocatalysts to harvest whole visible-light region photons and enhance solar energy conversion is a“holy grail”for researchers,but is still a challenging issue.Herein,based on the common polymeric carbon nitride(PCN),a hybrid co-catalysts system comprising plasmonic Au nanoparticles(NPs)and atomically dispersed Pt single atoms(PtSAs)with different functions was constructed to address this challenge.For the dual co-catalysts decorated PCN(PtSAs–Au_(2.5)/PCN),the PCN is photoexcited to generate electrons under UV and short-wavelength visible light,and the synergetic Au NPs and PtSAs not only accelerate charge separation and transfer though Schottky junctions and metal-support bond but also act as the co-catalysts for H_(2) evolution.Furthermore,the Au NPs absorb long-wavelength visible light owing to its localized surface plasmon resonance,and the adjacent PtSAs trap the plasmonic hot-electrons for H_(2) evolution via direct electron transfer effect.Consequently,the PtSAs–Au_(2.5)/PCN exhibits excellent broad-spectrum photocatalytic H_(2) evolution activity with the H_(2) evolution rate of 8.8 mmol g^(−1) h^(−1) at 420 nm and 264μmol g^(−1) h^(−1) at 550 nm,much higher than that of Au_(2.5)/PCN and PtSAs–PCN,respectively.This work provides a new strategy to design broad-spectrum photocatalysts for energy conversion reaction.展开更多
A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used ...A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used to characterize structure of hybrid MOC-16/g-C3N4, as well as UV-vis absorption spectrum and X-ray photoelectron spectroscopy were carried out to unveil photocatalytic mechanism. With the introduction of MOC-16, the absorption edge of MOC-16/g-C3N4 in UV-vis spectrum extended apparently to long-wavelength region compared with pristine g-C3N4. H2 evolution yielded with MOC-16/g-C3N4 in aqueous solution containing TEOA was much higher than that with RuL3/g-C3N4, Pd/RuL3/g-C3N4 and mixture of MOC-16 and g-C3N4, showing that the octahedral cage structure with high-efficient electron transfer and the interface interaction between MOC-16 and g-C3N4 were significant for improvement of H2 evolution.展开更多
Green reactions not only provide us chemical products without any pollution,but also offer us the viable technology to realize difficult tasks in normal conditions.Photo-,photoelectro-,and electrocatalytic reactions a...Green reactions not only provide us chemical products without any pollution,but also offer us the viable technology to realize difficult tasks in normal conditions.Photo-,photoelectro-,and electrocatalytic reactions are indeed powerful tools to help us to embrace bright future.Especially,some gas-involved reactions are extremely useful to change our life environments from energy systems to liquid fuels and cost-effective products,such as H2 evolution(H2 production),02 evolution/reduction,CO2 reduction,N2 reduction(or N2 fixation) reactions.We can provide fuel cells clean H2 for electric vehicles from H2 evolution reaction(HER),at the same time,we also need highly efficient 02 reduction reaction(ORR) in fuel cells for improving the reaction kinetics.Moreover,we can get the clean oxidant O2 from water through O2 evolution reaction(OER),and carry out some reactions without posing any pollution to reaction systems.Furthermore,we can translate the greenhouse gas CO2 into useful liquid fuels through CO2 reduction reaction(CRR).Last but not the least,we can get ammonia from N2 reduction reaction(NRR),which can decrease energy input compared to the traditional Hubble process.These reactions,such as HER,ORR,OER,CRR and NRR could be realized through solar-,photoelectro-and electro-assisted ways.For them,the catalysts used play crucial roles in determining the efficiency and kinds of products,so we should consider the efficiency of catalysts.However,the cost,synthetic methods of catalysts should also be considered.Nowadays,significant progress has been achieved,however,many challenges still exist,reaction systems,catalysts underlying mechanisms,and so on.As extremely active fields,we should pay attention to them.Under the background,it has motivated us to contribute with a roadmap on ’GasInvolved Photo-and Electro-Catalysis’.展开更多
Carbon nitride(g-C_(3)N_(4))is an attractive photocatalyst but commonly suffers from high photogenerated electron-hole recombination rate,low specific surface area,and narrow visible-light response range.Herein,3D ord...Carbon nitride(g-C_(3)N_(4))is an attractive photocatalyst but commonly suffers from high photogenerated electron-hole recombination rate,low specific surface area,and narrow visible-light response range.Herein,3D ordered macroporous(3DOM)g-C_(3)N_(4)/CdS was constructed by a feasible and inexpensive synthesis strategy of using template and light-assisted methods to solve the above problems.The formed heterostructure with suitable morphology,band structure,and extended light absorption range is beneficial to promoting photocatalytic Hgeneration.3DOM g-C_(3)N_(4)/Cd S exhibits a high Hproduce rate of718.6μmol hg,which is 73.3 times higher than that of g-C_(3)N_(4)and 25.4 times higher than that of3DOM g-C_(3)N_(4).The 3DOM structure can effectively increase the path length of light of g-C_(3)N_(4),improve the light energy conversion efficiency,and shorten the carrier transport distance.CdS enhances visiblelight response and produces many surface sites.Constructing a stable and tight interface between 3DOM g-C_(3)N_(4)and Cd S can promote the migration of photogenerated electrons and holes and consequently the visible-light catalytic activity.This study offers an effective designing strategy for heterostructure photocatalysts to achieve high activity and stable solar H2production.展开更多
Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this cata...Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this catalyst were investigated systematically. The morphology of the obtained nanorod is a regular hexagonal prism with 100-200 nm in diameter. The calcination temperature and time were optimized carefully to achieve the highest photoelectrochemical performance. The as-fabricated hybrid system achieved a photocurrent density up to 6.5 mA/cm2 and H2 evolution rate of 240 μmol·cm-2·h-1 at 0 V vs. Ag/AgCl, which is about 2-fold higher than that of the bare CdS nanorod arrays. The PEC performance exceeds those previously reported similar systems. A direct Z-scheme photocatalytic mechanism was proposed based on the structure and photoelectrochemical performance characterization results, which can well explain the high separation efficiency of photoinduced carriers and the excellent redox ability.展开更多
The random mobility of charge carriers is a main factor causing the low photocatalytic efficiency of gCN.Thus,the controllable migration of charge carriers is a rational strategy to suppress the charge recombination a...The random mobility of charge carriers is a main factor causing the low photocatalytic efficiency of gCN.Thus,the controllable migration of charge carriers is a rational strategy to suppress the charge recombination and facilitate charge separation.Herein,an ethylenediamine modified g-C_(3)N_(4)displays improved photocatalytic activity.The excellent charge separation efficiency is confirmed to be a key factor for the enhancement.The TEM observation after photo-depositing Pt nanoparticles and DFT calculations verify the accumulation of electrons on some areas of g-C_(3)N_(4)surface.The increased-NH_(2)groups significantly tune the electronic structure of g-C_(3)N_(4)after the modification.The generation of midgap states also affects the charge separation.Our reports provide a simple method to manage the migration of charge carriers and enable electrons directional transfer,which suppresses the recombination and improves the photocatalytic activity.展开更多
基金supported by the National Key Research and Development Program of China(2022YFB3803600)the National Natural Science Foundation of China(52276212)+4 种基金the Natural Science Foundation of Jiangsu Province(BK20231211)the Suzhou Science and Technology Program(SYG202101)the Key Research and Development Program in Shaanxi Province of China(2023-YBGY-300)the Zhuhai Innovation and Entrepreneurship Team Project(2120004000225)the China Fundamental Research Funds for the Central Universities。
文摘Recent interest in photocatalytic water splitting has intensified the demand in the development of photocatalysts capable of harnessing the full solar-spectrum.This study introduces a novel WO_(x)/ZnIn_(2)S_(4)Zscheme heterojunction,prepared by depositing ZnIn_(2)S_(4)(ZIS)nanosheets onto WO_(x)nanorods,enabling efficient photothermal-coupled photocatalytic H_(2)evolution.The success relies on the engineered oxygen vacancies within WO_(x)nanorods,which not only confer excellent photothermal properties lowering the reaction barrier but also create defect levels in WO_(x)facilitating Z-scheme electron transfer from these levels to the valence band of ZIS.Consequently,the optimized WO_(x)/ZIS heterojunction exhibits a remarkable H_(2)evolution rate of 33.91 mmol h^(-1)g^(-1)with an apparent quantum efficiency of 23.6%at 400 nm.This study provides a new strategy for developing efficient Z-scheme heterojunctions with broadspectrum solar hydrogen production capabilities.
基金Projects(11JJ3020,10JJ9015)supported by Hunan Provincial Natural Science Foundation of ChinaProject supported by the Construct Program of the Key Discipline in Hunan Province,China
文摘The oxysulfide La3NbS2O5 was synthesized by sulfurization using H2S and characterized by X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectroscopy （DRS） and field emission scanning electron microscopy （FE-SEM）. The relationship between the sulfurization conditions and the photocatalytic activities for H2 evolution was investigated. Sulfurization method allowed for synthesis of La3NbS2O5 at much lower temperatures and significantly shortened reaction time of 1 h compared with conventional solid-state techniques. The particle morphologies were regular platelike with sizes of 0.1-0.6μm and smooth surfaces. The highest activity for H2 evolution was obtained at 1073 K for 1 h, which was about 1.83 times that of La3NbS2O5 prepared by solid-state method.
文摘Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D CdS/MoO3‒x heterojunction has been synthesized by the growth of 0D CdS nanoparticles on 2D plasmonic MoO3‒x elliptical nanosheets via a simple coprecipitation method.Taking advantage of the LSPR effect of the MoO3‒x elliptical nanosheets,the light absorption of the CdS/MoO3‒x heterojunction was extended from 600 nm to the near-infrared region(1400 nm).Furthermore,the introduction of 2D plasmonic MoO3‒x elliptical nanosheets not only provided a platform for the growth of CdS nanoparticles,but also contributed to the construction of an LSPR-enhanced S-scheme structure due to the interface between the MoO3‒x and CdS,accelerating the separation of light-induced electrons and holes.Therefore,the CdS/MoO3‒x heterojunction exhibited higher photocatalytic H2 generation activity than pristine CdS under visible light irradiation,including under 420,450,550,and 650 nm monochromic light,as well as improved photo-corrosion performance.
基金supported by the National Natural Science Foundation of China(51502155,51572152,21673127,21671119)the Research Project of Hubei Provincial Department of Education(D20151203)the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences(20170020)~~
文摘Willow branch-shaped MoS2/CdS heterojunctions are successfully synthesized for the first time by a facile one-pot hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption measurements, diffuse reflectance spectroscopy, and photoelectrochemical and photoluminescence spectroscopy tests. The photocatalytic hydrogen evolution activities of the samples were evaluated under visible light irradiation. The resulting MoS2/CdS heterojunctions exhibit a much improved photocatalytic hydrogen evolution activity than that obtained with CdS and MoS2. In particular, the optimized MC-5 (5 at.% MoS2/CdS) photocatalyst achieved the highest hydrogen production rate of 250.8 μmol h–1, which is 28 times higher than that of pristine CdS. The apparent quantum efficiency (AQE) at 420 nm was 3.66%. Further detailed characterizations revealed that the enhanced photocatalytic activity of the MoS2/CdS heterojunctions could be attributed to the efficient transfer and separation of photogenerated charge carriers resulting from the core-shell structure and the close contact between MoS2 nanosheets and CdS single-crystal nanorods, as well as to increased visible light absorption. A tentative mechanism for photocatalytic H2 evolution by MoS2/CdS heterojunctions was proposed. This work will open up new opportunities for developing more efficient photocatalysts for water splitting.
基金Project supported by the National Natural Science Foundation of China(21271055,21471040)
文摘This review focused on rare-earth elements containing inorganic semiconductor photocatalysts for efficient solar energy conversion. We also summarized the recent progress in the modification of the transition metal oxides and mixed oxides with rare earth ions. In the first section, we surveyed a variety of rare-earth elements modified TiO2 photocatalysts. Attributed to the modifica-tion with rare-earth elements, phase transformation of TiO2 from anatase to rutile was inhibited. Furthermore, the light-absorbing property of the TiO2 modified with rare-earth elements was also enhanced. In the second section, we summarized the effects of rare-earth elements on the modification of transition metal mixed oxides. It was believed that the corner-shared octahedral units in the form of networks, chains and slabs within the mixed oxide lattice were essential for the enhancement of the photocatalytic activity. In the last section, the strategy for the design of NIR or IR response upconversion composite photocatalysts was also discussed.
基金the National Natural Science Foundation of China(21975084,51672089)Special Funding on Applied Science and Technology in Guangdong(2017B020238005)+2 种基金the State Key Laboratory of Advanced Technology for Material Synthesis and Processing(Wuhan University of Technology)(2015-KF-7)State Scholarship Fund of China Scholarship Council(200808440114)the Ding Ying Talent Project of South China Agricultural University for their support
文摘Converting solar energy into clean and sustainable chemical fuels is a promising strategy for exploiting renewable energy.The application of photocatalytic water splitting technology in hydrogen production is important for sustainable energy development and environmental protection.In this study,for the first time,2D Cu7S4 co-catalysts were coupled on the surface of a CdS nanosheet photocatalyst by a one-step ultrasonic-assisted electrostatic self-assembly method at room temperature.The as-fabricated 2D^-2D CdS/Cu7S4 layered heterojunctions were demonstrated to be advanced composite photocatalysts that enhance the water splitting efficiency toward hydrogen production.The highest hydrogen evolution rate of the 2D^-2D CdS/2%Cu7S4 binary heterojunction photocatalyst was up to 27.8 mmol g^-1 h^-1 under visible light irradiation,with an apparent quantum efficiency of 14.7%at 420 nm,which was almost 10.69 times and 2.65 times higher than those of pure CdS nanosheets(2.6 mmol g^-1 h^-1)and CdS-2%CuS(10.5 mmol g^-1 h^-1),respectively.The establishment of the CdS/Cu7S4 binary-layered heterojunction could not only enhance the separation of photogenerated electron-hole(e--h+)pairs,improve the transfer of photo-excited electrons,and prolong the life-span of photo-generated electrons,but also enhance the light absorption and hydrogen-evolution kinetics.All these factors are important for the enhancement of the photocatalytic activity.Expectedly,the 2D^-2D interface coupling strategy based on CdS NSs can be extensively exploited to improve the hydrogen-evolution activity over various kinds of conventional semiconductor NSs.
文摘The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.
基金the National Natural Science Foundation of China(21503096,21407067)the Natural Science Foundation of Jiangsu Province(BK20140506)~~
文摘Porous C‐I codoped carbon nitride materials were synthesized by in‐situ codoping with iodized ionic liquid followed by post‐thermal treatment in air.The effects of doping content of C‐I codoping with different amounts of ionic liquid on the structural,optical and photocatalytic properties of the samples were investigated.Characterization results show that more compact interlayer sacking can be achieved by post‐thermal treatment.Combined with C‐I codoping by insertion of ionic liquids,much enlarged surface area but optimized sp2 conjugated heterocyclic structure can be found in the catalysts.Optical and energy band analysis results evidence that the light absorptions especially in visible light region are significantly improved.Although the band gap of porous C‐I codoped samples enlarge because of the generation of porous,the negatively shifted conduction band position thermodynamically supplies stronger motivation for water reduction.Photoelectricity tests reveal that the photo‐induced electron density was increased after C‐I codoping modification.Also,the recombination rate of electron‐hole pairs is remarkably inhibited.The catalysts with moderate C‐I codoing content perform sharply enhanced photocatalytic H2 evolution activity under visible light irradiation.A H2 evolution rate of 168.2μmol/h was achieved and it was more than 9.8 times higher than pristine carbon nitride.This study demonstrates a novel non‐metal doping strategy for synthesis and optimization of polymer semiconductor with gratifying photocatalytic H2 evolution performance from water hydrolysis.
基金supported by the National Natural Science Foundation of China(21477094)the Fundamental Research Funds for the Central Universities(WUT 2017IB002)~~
文摘The development of efficient photocatalytic H2-evolution materials requires both rapid electron transfer and an effective interfacial catalysis reaction for H2 production. In addition to the well-known noble metals, low-cost and earth-abundant non-noble metals can also act as electron- transfer mediators to modify photocatalysts. However, as almost all non-noble metals lack the interfacial catalytic active sites required for the H2-evolution reaction, the enhancement of the photocatalytic performance is limited. Therefore, the development of new interfacial active sites on metal-modified photocatalysts is of considerable importance. In this study, to enhance the photocatalytic evolution of H2 by Ni-modified TiO2, the formation of NiSx as interfacial active sites was promoted on the surface of Ni nanoparticles. Specifically, the co-modified TiO2/Ni-NiSx photocatalysts were prepared via a two-step process involving the photoinduced deposition of Ni on the TiO2 surface and the subsequent formation of NiSx on the Ni surface by a hydrothermal reaction method. It was found that the TiO2/Ni-NiSx photocatalysts exhibited enhanced photocatalytic H2-evolution activity. In particular, TiO2/Ni-NiSx(30%) showed the highest photocatalytic rate (223.74 μmol h.1), which was greater than those of TiO2, TiO2/Ni, and TiO2/NiSx by factors of 22.2, 8.0, and 2.2, respectively. The improved H2-evolution performance of TiO2/Ni-NiSx could be attributed to the excellent synergistic effect of Ni and NiSx, where Ni nanoparticles function as effective mediators to transfer electrons from the TiO2 surface and NiSx serves as interfacial active sites to capture H+ ions from solution and promote the interfacial H2-evolution reaction. The synergistic effect of the non-noble metal cocatalyst and the interfacial active sites may provide new insights for the design of highly efficient photocatalytic materials.
基金supported by the National Natural Science Foundation of China(51572295,21273285,21003157)the Beijing Nova Program(2008B76)the Science Foundation of China University of Petroleum Beijing(KYJJ2012-06-20 and 2462016YXBS05)~~
文摘PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution of the g-C3N4 nanosheets shows that it was significantly enhanced when PtPd alloy NPs were introduced as a co-catalyst. The 0.2 wt% PtPd/g-C3N4 composite photocatalyst gave a maximum H2 production rate of 1600.8 μmol g^–1 h^–1. Furthermore, when K2HPO4 was added to the reaction system, the H2 production rate increased to 2885.0 μmol g^–1 h^–1. The PtPd/g-C3N4 photocatalyst showed satisfactory photocatalytic stability and was able to maintain most of its photocatalytic activity after four experimental photocatalytic cycles. In addition, a possible mechanism for the enhanced photocatalytic activity was proposed and verified by various photoelectric techniques. These results demonstrate that the synergistic effect between PtPd and g-C3N4 helps to greatly improve the photocatalytic activity of the composite photocatalyst.
基金financially supported by the National Natural Science Foundation of China(Nos.21975163 and 21905181)。
文摘The inefficiency of water splitting is mainly due to the sluggish anodic water oxidation reaction. Replacing water oxidation with thermodynamically more favorable selective methanol oxidation reaction and developing robust bifunctional electrocatalysts are of great significance. Herein, a hierarchical heteronanostructure with Ni–Co layered double hydroxide(LDH) ultrathin nanosheets coated on cobalt phosphide nanosheets arrays(CoxP@NiCo-LDH) are fabricated and used for co-electrolysis of methanol/water to co-produce value-added formate and hydrogen with saving energy. Benefiting from the fast charge transfer introduced by phosphide nanoarrays, the synergy in nanosheets catalysts with hetero-interface,CoxP@NiCo-LDH/Ni foam(NF) exhibits superior electrocatalytic performance(10 mA cm-2@ 1.24 V and-0.10 V for methanol selective oxidation and hydrogen evolution reaction, respectively). Furthermore,CoxP@NiCo-LDH/NF-based symmetric two-electrode electrolyzer drives a current density of 10 m A cm-2 with a low cell voltage of only 1.43 V and the Faradaic efficiency towards the generation of formate and H2 are close to 100% in the tested range of current density(from 40 to 200 m A cm-2). This work highlights the positive effect of hetero-interaction in the design of more efficient eletrocatalysts and might guide the way towards facile upgrading of alcohols and energy-saving electrolytic H2 co-generation.
文摘In recent years,ternary heterostructures(HSs)composed of three semiconductors have attracted significant attention because of the effective separation and transfer of photogenerated electrons and holes in these materials.In this work,new ternary Cd S/Zn S/Zn O(CZZ)HSs with one-dimensional(1D)nanofiber morphology have been successfully fabricated for the first time by a series of processes:electrospinning Zn O nanofibers,sulfurizing Zn O in situ to form Zn S/Zn O binary HSs,and depositing Cd S quantum dots in situ on the Zn S/Zn O HSs.Benefiting from the efficient separation and transfer of photoinduced charge carriers,the optimized CZZ ternary HSs exhibit a hydrogen evolution rate of 51.45 mmol h^-1 g^-1(quantum efficiency:26.88%at 420 nm)without any co-catalyst,which is 93.54 and 2.28 times higher than those exhibited by pristine Zn O and Zn S/Zn O binary HSs,respectively,under the same conditions.Furthermore,the rate of hydrogen evolution over the 1D CZZ nanofibers is significantly higher than that over 2D CZZ nanosheets(27.25 mmol h^-1 g^-1,in the presence of a Pt co-catalyst)prepared by the same sulfurization and deposition procedures.This can be ascribed to the significantly smaller geometric sizes of 1D nanofibers compared to those of 2D nanosheets,resulting in effectively suppressed recombination of photogenerated charge carriers and promotion of photocatalytic H2 evolution performance.
文摘Construction of multi-channels of photo-carrier migration in photocatalysts is favor to boost conversion efficiency of solar energy by promoting the charge separation and transfer.Herein,a ternary ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene hybrid composed of S-scheme junction integrated Schottky-junction was fabricated using a simple hydrothermal approach.All the components(g-C_(3)N_(4),ZnIn_(2)S_(4) and Ti_(3)C_(2) MXene)demonstrated two-dimensional(2D)nanosheets structure,leading to the formation of a 2D/2D/2D sandwich-like structure with intimate large interface for carrier migration.Furthermore,the photogenerated carriers on the g-C_(3)N_(4) possessed dual transfer channels,including one route in S-scheme transfer mode between the g-C_(3)N_(4) and ZnIn_(2)S_(4) and the other route in Schottky-junction between g-C_(3)N_(4) and Ti_(3)C_(2) MXene.Consequently,a highly efficient carrier separation and transport was realized in the ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene heterojunction.This ternary sample exhibited wide light response from 200 to 1400 nm and excellent photocatalytic H_(2) evolution of 2452.1μmol∙g^(–1)∙h^(–1),which was 200,3,1.5 and 1.6 times of g-C_(3)N_(4),ZnIn_(2)S_(4),ZnIn_(2)S_(4)/Ti_(3)C_(2) MXene and g-C_(3)N_(4)/ZnIn_(2)S_(4) binary composites.This work offers a paradigm for the rational construction of multi-electron pathways to regulate the charge separation and migration via the introduction of dual-junctions in catalytic system.
文摘Developing highly active catalysts for photo/electrocatalytic water splitting is an attractive strategy to produce H2 as a renewable energy source.In this study,a new nickel boron oxide/graphdiyne(NiBi/GDY)hybrid catalyst was prepared by a facile synthetic approach.Benefitting from the strong electron donating ability of graphdiyne,NiBi/GDY showed an optimized electronic structure containing lower valence nickel atoms and demonstrated improved catalytic performance.As expected,NiBi/GDY displayed a high photocatalytic H2 evolution rate of 4.54 mmol g^(-1)h^(-1),2.9 and 4.5 times higher than those of NiBi/graphene and NiBi,respectively.NiBi/GDY also displayed outstanding electrocatalytic H2 evolution activity in 1.0 M KOH solution,with a current density of 400 mA/cm^(2)at an overpotential of 478.0 mV,which is lower than that of commercial Pt/C(505.3 mV@400 mA/cm^(2)).This work demonstrates that GDY is an ideal support for the development of highly active catalysts for photo/electrocatalytic H2 evolution.
基金supported by the National Natural Science Foundation of China(Grant No.51871078 and 52071119)Interdisciplinary Research Foundation of HIT(Grant No.IR2021208)+1 种基金State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS38)Heilongjiang Science Foundation(No.LH2020B006).
文摘ABSTRACT Rationally designing broad-spectrum photocatalysts to harvest whole visible-light region photons and enhance solar energy conversion is a“holy grail”for researchers,but is still a challenging issue.Herein,based on the common polymeric carbon nitride(PCN),a hybrid co-catalysts system comprising plasmonic Au nanoparticles(NPs)and atomically dispersed Pt single atoms(PtSAs)with different functions was constructed to address this challenge.For the dual co-catalysts decorated PCN(PtSAs–Au_(2.5)/PCN),the PCN is photoexcited to generate electrons under UV and short-wavelength visible light,and the synergetic Au NPs and PtSAs not only accelerate charge separation and transfer though Schottky junctions and metal-support bond but also act as the co-catalysts for H_(2) evolution.Furthermore,the Au NPs absorb long-wavelength visible light owing to its localized surface plasmon resonance,and the adjacent PtSAs trap the plasmonic hot-electrons for H_(2) evolution via direct electron transfer effect.Consequently,the PtSAs–Au_(2.5)/PCN exhibits excellent broad-spectrum photocatalytic H_(2) evolution activity with the H_(2) evolution rate of 8.8 mmol g^(−1) h^(−1) at 420 nm and 264μmol g^(−1) h^(−1) at 550 nm,much higher than that of Au_(2.5)/PCN and PtSAs–PCN,respectively.This work provides a new strategy to design broad-spectrum photocatalysts for energy conversion reaction.
基金supported by the National Natural Science Foundation of China(21875293,21821003,21890380,21720102007,21572280)the Natural Science Foundation of Guangdong Province(2016A030313268)+2 种基金the STP Project of Guangzhou(201804010386,201707010114)the Fundamental Research Funds for the Central Universities(17lgzd18,17lgzd01)the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province~~
文摘A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used to characterize structure of hybrid MOC-16/g-C3N4, as well as UV-vis absorption spectrum and X-ray photoelectron spectroscopy were carried out to unveil photocatalytic mechanism. With the introduction of MOC-16, the absorption edge of MOC-16/g-C3N4 in UV-vis spectrum extended apparently to long-wavelength region compared with pristine g-C3N4. H2 evolution yielded with MOC-16/g-C3N4 in aqueous solution containing TEOA was much higher than that with RuL3/g-C3N4, Pd/RuL3/g-C3N4 and mixture of MOC-16 and g-C3N4, showing that the octahedral cage structure with high-efficient electron transfer and the interface interaction between MOC-16 and g-C3N4 were significant for improvement of H2 evolution.
基金The financial support from the National Natural Science Foundation of China (Nos. 51772312, 21671197)
文摘Green reactions not only provide us chemical products without any pollution,but also offer us the viable technology to realize difficult tasks in normal conditions.Photo-,photoelectro-,and electrocatalytic reactions are indeed powerful tools to help us to embrace bright future.Especially,some gas-involved reactions are extremely useful to change our life environments from energy systems to liquid fuels and cost-effective products,such as H2 evolution(H2 production),02 evolution/reduction,CO2 reduction,N2 reduction(or N2 fixation) reactions.We can provide fuel cells clean H2 for electric vehicles from H2 evolution reaction(HER),at the same time,we also need highly efficient 02 reduction reaction(ORR) in fuel cells for improving the reaction kinetics.Moreover,we can get the clean oxidant O2 from water through O2 evolution reaction(OER),and carry out some reactions without posing any pollution to reaction systems.Furthermore,we can translate the greenhouse gas CO2 into useful liquid fuels through CO2 reduction reaction(CRR).Last but not the least,we can get ammonia from N2 reduction reaction(NRR),which can decrease energy input compared to the traditional Hubble process.These reactions,such as HER,ORR,OER,CRR and NRR could be realized through solar-,photoelectro-and electro-assisted ways.For them,the catalysts used play crucial roles in determining the efficiency and kinds of products,so we should consider the efficiency of catalysts.However,the cost,synthetic methods of catalysts should also be considered.Nowadays,significant progress has been achieved,however,many challenges still exist,reaction systems,catalysts underlying mechanisms,and so on.As extremely active fields,we should pay attention to them.Under the background,it has motivated us to contribute with a roadmap on ’GasInvolved Photo-and Electro-Catalysis’.
基金financially supported by the National Natural Science Foundation of China(Nos.51862023,51662030 and 21868016)the Natural Science Foundation of Jiangxi Province(No.20212BAB204051)。
文摘Carbon nitride(g-C_(3)N_(4))is an attractive photocatalyst but commonly suffers from high photogenerated electron-hole recombination rate,low specific surface area,and narrow visible-light response range.Herein,3D ordered macroporous(3DOM)g-C_(3)N_(4)/CdS was constructed by a feasible and inexpensive synthesis strategy of using template and light-assisted methods to solve the above problems.The formed heterostructure with suitable morphology,band structure,and extended light absorption range is beneficial to promoting photocatalytic Hgeneration.3DOM g-C_(3)N_(4)/Cd S exhibits a high Hproduce rate of718.6μmol hg,which is 73.3 times higher than that of g-C_(3)N_(4)and 25.4 times higher than that of3DOM g-C_(3)N_(4).The 3DOM structure can effectively increase the path length of light of g-C_(3)N_(4),improve the light energy conversion efficiency,and shorten the carrier transport distance.CdS enhances visiblelight response and produces many surface sites.Constructing a stable and tight interface between 3DOM g-C_(3)N_(4)and Cd S can promote the migration of photogenerated electrons and holes and consequently the visible-light catalytic activity.This study offers an effective designing strategy for heterostructure photocatalysts to achieve high activity and stable solar H2production.
基金supported by the National Natural Science Foundation of China(No.U1632273,No.21673214,No.U1732272,and No.U1832165)
文摘Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this catalyst were investigated systematically. The morphology of the obtained nanorod is a regular hexagonal prism with 100-200 nm in diameter. The calcination temperature and time were optimized carefully to achieve the highest photoelectrochemical performance. The as-fabricated hybrid system achieved a photocurrent density up to 6.5 mA/cm2 and H2 evolution rate of 240 μmol·cm-2·h-1 at 0 V vs. Ag/AgCl, which is about 2-fold higher than that of the bare CdS nanorod arrays. The PEC performance exceeds those previously reported similar systems. A direct Z-scheme photocatalytic mechanism was proposed based on the structure and photoelectrochemical performance characterization results, which can well explain the high separation efficiency of photoinduced carriers and the excellent redox ability.
基金supported by Shenzhen Key Laboratory of Solid State Batteries(ZDSYS20180208184346531)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)+3 种基金Guangdong Provincial Key Laboratory of Catalysis(2020B121201002)Shenzhen Clean Energy Research Institute(CERI-KY-2019-003)the National Natural Science Foundation of China(2017M611446)supported by the Core Research Facilities at SUSTech that receives support from a Presidential fund and the Development and Reform Commission of Shenzhen Municipality。
文摘The random mobility of charge carriers is a main factor causing the low photocatalytic efficiency of gCN.Thus,the controllable migration of charge carriers is a rational strategy to suppress the charge recombination and facilitate charge separation.Herein,an ethylenediamine modified g-C_(3)N_(4)displays improved photocatalytic activity.The excellent charge separation efficiency is confirmed to be a key factor for the enhancement.The TEM observation after photo-depositing Pt nanoparticles and DFT calculations verify the accumulation of electrons on some areas of g-C_(3)N_(4)surface.The increased-NH_(2)groups significantly tune the electronic structure of g-C_(3)N_(4)after the modification.The generation of midgap states also affects the charge separation.Our reports provide a simple method to manage the migration of charge carriers and enable electrons directional transfer,which suppresses the recombination and improves the photocatalytic activity.
