Carbon dots(C-Dots)have received much attention in photocatalyst design and mechanism studies due to their precise size control,unique photoelectrical properties,and abundant surface-active sites,but their catalytic p...Carbon dots(C-Dots)have received much attention in photocatalyst design and mechanism studies due to their precise size control,unique photoelectrical properties,and abundant surface-active sites,but their catalytic performance is still limited by issues such as severe charge recombination,agglomeration,and poor stability,which mainly stem from the small size and high surface area.A major solution to these problems is loading the zero-dimensional(0D)C-Dots onto ultrathin two-dimensional(2D)nanosheets to form 0D/2D nanocomposites.In this review,we systematically introduce the progress on the design and construction of 0D/2D heterojunction photocatalysts based on C-Dots,and their applications across different photocatalytic reactions,such as hydrogen production,carbon dioxide reduction,and hydrogen peroxide synthesis.We also discuss the key role of various types of 0D/2D heterojunctions according to different photocatalytic mechanisms and corresponding promoting strategies for enhancing the catalytic activity,accelerating charge transfer,and coupling different sites for the surface oxidation/reduction reactions.Finally,the challenges and future research directions associated with these systems are discussed.展开更多
Green energy generation is an indispensable task to concurrently resolve fossil fuel depletion and environmental issues to align with the global goals of achieving carbon neutrality.Photocatalysis,a process that trans...Green energy generation is an indispensable task to concurrently resolve fossil fuel depletion and environmental issues to align with the global goals of achieving carbon neutrality.Photocatalysis,a process that transforms solar energy into clean fuels through a photocatalyst,represents a felicitous direction toward sustainability.Eco-rich metal-free graphitic carbon nitride(g-C_(3)N_(4))is profiled as an attractive photocatalyst due to its fascinating properties,including excellent chemical and thermal stability,moderate band gap,visible light-active nature,and ease of fabrication.Nonetheless,the shortcomings of g-C_(3)N_(4)include fast charge recombination and limited surface-active sites,which adversely affect photocatalytic reactions.Among the modification strategies,point-to-face contact engineering of 2D g-C_(3)N_(4)with 0D nanomaterials represents an innovative and promising synergy owing to several intriguing attributes such as the high specific surface area,short effective charge-transfer pathways,and quantum confinement effects.This review introduces recent advances achieved in experimental and computational studies on the interfacial design of 0D nanostructures on 2D g-C_(3)N_(4)in the construction of point-to-face heterojunction interfaces.Notably,0D materials such as metals,metal oxides,metal sulfides,metal selenides,metal phosphides,and nonmetals on g-C_(3)N_(4)with different charge-transfer mechanisms are systematically discussed along with controllable synthesis strategies.The applications of 0D/2D g-C_(3)N_(4)-based photocatalysts are focused on solar-to-energy conversion via the hydrogen evolution reaction,the CO_(2)reduction reaction,and the N2 reduction reaction to evaluate the photocatalyst activity and elucidate reaction pathways.Finally,future perspectives for developing high-efficiency 0D/2D photocatalysts are proposed to explore potential emerging carbon nitride allotropes,large-scale production,machine learning integration,and multidisciplinary advances for technological breakthroughs.展开更多
It is still of gigantic challenging to design and to optimize photocatalytic systems with cost-efficiency for photocatalytic hydrogen evolution from water splitting.Herein,noble-metal-free 2D CoP nanosheets were prepa...It is still of gigantic challenging to design and to optimize photocatalytic systems with cost-efficiency for photocatalytic hydrogen evolution from water splitting.Herein,noble-metal-free 2D CoP nanosheets were prepared by a phosphorization method using Co(OH)2 nanosheets as precursors,and then employed as photocatalytic cocatalyst and template to make 0D Ti O2 nanoparticles in-situ grow on the surface for construction of 0D/2D TiO_(2)/CoP hybrid by a simple hydrothermal method.The TiO2/CoP hybrid with the optimal ratio of CoP cocatalyst(1 wt.%)manifested significantly improved photocatalytic H_(2) evolution rate of 0.604 mmol g^(-1) h^(-1),which is tenfold in comparison to pure TiO2(0.06 mmol g^(-1) h^(-1).The mechanism of performance enhancement was fully investigated and supposed that 2D CoP nanosheets cocatalyst can enhance the photo-absorption and provide more active sites for water reduction reaction;furthermore,2D CoP nanosheets with smaller work function and high conductivity would form an Ohmicjunction with TiO_(2) nanoparticles,which can significantly accelerate the separation of photo-generated charge carriers and improve the exploitation of the photoexcited electrons in water redox reaction.This work is anticipated to impel more perspicacity into synthesizing innovative photocatalytic systems with 2D transition metal phosphides cocatalysts for attaining high photocatalytic H_(2) evolving pursuit.展开更多
Developing multi-functional and low-cost noble-metal-free catalysts such as transition metal phosphides(TMPs)to replace noble-metal is of practical significance for energy conversion and storage.However,the low-durabi...Developing multi-functional and low-cost noble-metal-free catalysts such as transition metal phosphides(TMPs)to replace noble-metal is of practical significance for energy conversion and storage.However,the low-durability and the agglomeration phenomenon during the electrochemical process limit their practical applications.Herein,using metal–organic frameworks(MOFs)as the precursor and a combined strategy of gradient temperature calcination and thermal phosphorization,a 0D/2D heterostructure of NiCoFe-P quantum dots(QDs)anchored on porous carbon was successfully developed as highly efficient electrode materials for overall water splitting and supercapacitors.Owing to this distinctive 0D/2D heterostructure and the synergistic effect of multi-metallic TMPs,the NiCoFe-P/C exhibits excellent electrocatalytic activity and durability of HER(87 mV at 10 mA cm^(-2))and OER(257 mV at 100 mA cm^(-2))in the KOH electrolyte.When NiCoFe-P/C is used as the two electrodes of electrolyzed water,only 1.55 V can drive the current density to 10 m A cm^(-2).At the same time,our NiCoFe-P/C possessed extraordinary property for charge storage.In particular,an ultra-high energy density of 100.8 Wh kg^(-1) was achieved at a power density of 900.0 W kg^(-1) for our assembled hybrid supercapacitor device NiCoFe-P/C(2:1)//activated carbon(AC).This work may open a potential way for the design of 0D/2D hybrid multifunctional nanomaterials based on TMPs QDs.展开更多
Photocatalytic water splitting for hydrogen production(H_(2))is one of the main potential applications of photocatalytic technology,which can use solar energy as the energy required for chemical reactions to alleviate...Photocatalytic water splitting for hydrogen production(H_(2))is one of the main potential applications of photocatalytic technology,which can use solar energy as the energy required for chemical reactions to alleviate the energy crisis.In this work,zero-dimensional/two-dimensional(0D/2D)contact surface CdS/α-Fe_(2)O_(3)(CF)heterojunction photocatalyst was synthesized via a simple solvothermal method.Photocatalytic hydrogen production experiments revealed that the CF-15 sample shows the optimal photocatalytic H_(2)rate(1806μmol·h^(-1)·g^(-1))and apparent quantum efficiency(AQE=13.7%atλ=420 nm).The enhancement of photocatalytic performance is mainly attributed to the contact of 0D/2D interface and the synergistic effect of Z-scheme electron transfer mechanism.This work provides an effective way for modified composite semiconductor photocatalyst by constructing special interface heterojunction to achieve highly efficiently catalysis.展开更多
The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanoshe...The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanosheets/FeOOH quantum dots/ZnIn_(2)S_(4)nanosheets(CNFeZn)dual Z-scheme system(DZSS)has been successfully constructed using electrostatic self-assembly method.Owing to the band structure and elaborate morphology of 2D g-C_(3)N_(4),0D FeOOH and 2D ZnIn_(2)S_(4)in unique designed DZSS,plenty of spatial charge transfer channels are formed between the g-C_(3)N_(4)/FeOOH and FeOOH/ZnIn_(2)S_(4)interfaces,which greatly accelerate the charge separation and transfer.As bifunctional catalysts,CNFeZn DZSS achieves the highest H_(2)evolution rate of~436.6 mmol/h with a great promotion of~10.6 folds and~6.9 folds compared to pristine g-C_(3)N_(4)and ZnIn_(2)S_(4),respectively.Meanwhile,the H_(2)O_(2)production rate reached~301.19 mmol/L after 60 min irradiation,up to~5.1 times and~2.3 times that of pristine g-C_(3)N_(4)and ZnIn_(2)S_(4).Experiment and DFT calculation further confirmed that the stable double built-in electronic field can be formed owing to the electron configuration between double interfaces,and reveal that the ample atomic-level charge transfer channels were established in the strong interaction connected double interfaces,which can act as the charge migration pathway promote the separation of photogenerated charges.展开更多
基金supported by the National Natural Science Foundation of China(22278194 and 21908081)
文摘Carbon dots(C-Dots)have received much attention in photocatalyst design and mechanism studies due to their precise size control,unique photoelectrical properties,and abundant surface-active sites,but their catalytic performance is still limited by issues such as severe charge recombination,agglomeration,and poor stability,which mainly stem from the small size and high surface area.A major solution to these problems is loading the zero-dimensional(0D)C-Dots onto ultrathin two-dimensional(2D)nanosheets to form 0D/2D nanocomposites.In this review,we systematically introduce the progress on the design and construction of 0D/2D heterojunction photocatalysts based on C-Dots,and their applications across different photocatalytic reactions,such as hydrogen production,carbon dioxide reduction,and hydrogen peroxide synthesis.We also discuss the key role of various types of 0D/2D heterojunctions according to different photocatalytic mechanisms and corresponding promoting strategies for enhancing the catalytic activity,accelerating charge transfer,and coupling different sites for the surface oxidation/reduction reactions.Finally,the challenges and future research directions associated with these systems are discussed.
基金Ministry of Higher Education,Malaysia,Grant/Award Number:FRGS/1/2020/TK0/XMU/02/1Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2021A1515111019+1 种基金Hengyuan International Sdn.Bhd.,Grant/Award Number:EENG/0003Xiamen University Malaysia,Grant/Award Numbers:IENG/0038,ICOE/0001,XMUMRF/2019-C3/IENG/0013,XMUMRF/2021-C8/IENG/0041。
文摘Green energy generation is an indispensable task to concurrently resolve fossil fuel depletion and environmental issues to align with the global goals of achieving carbon neutrality.Photocatalysis,a process that transforms solar energy into clean fuels through a photocatalyst,represents a felicitous direction toward sustainability.Eco-rich metal-free graphitic carbon nitride(g-C_(3)N_(4))is profiled as an attractive photocatalyst due to its fascinating properties,including excellent chemical and thermal stability,moderate band gap,visible light-active nature,and ease of fabrication.Nonetheless,the shortcomings of g-C_(3)N_(4)include fast charge recombination and limited surface-active sites,which adversely affect photocatalytic reactions.Among the modification strategies,point-to-face contact engineering of 2D g-C_(3)N_(4)with 0D nanomaterials represents an innovative and promising synergy owing to several intriguing attributes such as the high specific surface area,short effective charge-transfer pathways,and quantum confinement effects.This review introduces recent advances achieved in experimental and computational studies on the interfacial design of 0D nanostructures on 2D g-C_(3)N_(4)in the construction of point-to-face heterojunction interfaces.Notably,0D materials such as metals,metal oxides,metal sulfides,metal selenides,metal phosphides,and nonmetals on g-C_(3)N_(4)with different charge-transfer mechanisms are systematically discussed along with controllable synthesis strategies.The applications of 0D/2D g-C_(3)N_(4)-based photocatalysts are focused on solar-to-energy conversion via the hydrogen evolution reaction,the CO_(2)reduction reaction,and the N2 reduction reaction to evaluate the photocatalyst activity and elucidate reaction pathways.Finally,future perspectives for developing high-efficiency 0D/2D photocatalysts are proposed to explore potential emerging carbon nitride allotropes,large-scale production,machine learning integration,and multidisciplinary advances for technological breakthroughs.
基金financially supported by the National Natural Science Foundation of China(Nos.51672113,21975110 and 21972058)。
文摘It is still of gigantic challenging to design and to optimize photocatalytic systems with cost-efficiency for photocatalytic hydrogen evolution from water splitting.Herein,noble-metal-free 2D CoP nanosheets were prepared by a phosphorization method using Co(OH)2 nanosheets as precursors,and then employed as photocatalytic cocatalyst and template to make 0D Ti O2 nanoparticles in-situ grow on the surface for construction of 0D/2D TiO_(2)/CoP hybrid by a simple hydrothermal method.The TiO2/CoP hybrid with the optimal ratio of CoP cocatalyst(1 wt.%)manifested significantly improved photocatalytic H_(2) evolution rate of 0.604 mmol g^(-1) h^(-1),which is tenfold in comparison to pure TiO2(0.06 mmol g^(-1) h^(-1).The mechanism of performance enhancement was fully investigated and supposed that 2D CoP nanosheets cocatalyst can enhance the photo-absorption and provide more active sites for water reduction reaction;furthermore,2D CoP nanosheets with smaller work function and high conductivity would form an Ohmicjunction with TiO_(2) nanoparticles,which can significantly accelerate the separation of photo-generated charge carriers and improve the exploitation of the photoexcited electrons in water redox reaction.This work is anticipated to impel more perspicacity into synthesizing innovative photocatalytic systems with 2D transition metal phosphides cocatalysts for attaining high photocatalytic H_(2) evolving pursuit.
基金financially supported by the National Natural Science Foundation of China(Grant No.21703137)the Starting Research Funds of Xidian University(Grant No.XJS211403)the Shanghai Sailing Program(Grant No.20YF1416100)。
文摘Developing multi-functional and low-cost noble-metal-free catalysts such as transition metal phosphides(TMPs)to replace noble-metal is of practical significance for energy conversion and storage.However,the low-durability and the agglomeration phenomenon during the electrochemical process limit their practical applications.Herein,using metal–organic frameworks(MOFs)as the precursor and a combined strategy of gradient temperature calcination and thermal phosphorization,a 0D/2D heterostructure of NiCoFe-P quantum dots(QDs)anchored on porous carbon was successfully developed as highly efficient electrode materials for overall water splitting and supercapacitors.Owing to this distinctive 0D/2D heterostructure and the synergistic effect of multi-metallic TMPs,the NiCoFe-P/C exhibits excellent electrocatalytic activity and durability of HER(87 mV at 10 mA cm^(-2))and OER(257 mV at 100 mA cm^(-2))in the KOH electrolyte.When NiCoFe-P/C is used as the two electrodes of electrolyzed water,only 1.55 V can drive the current density to 10 m A cm^(-2).At the same time,our NiCoFe-P/C possessed extraordinary property for charge storage.In particular,an ultra-high energy density of 100.8 Wh kg^(-1) was achieved at a power density of 900.0 W kg^(-1) for our assembled hybrid supercapacitor device NiCoFe-P/C(2:1)//activated carbon(AC).This work may open a potential way for the design of 0D/2D hybrid multifunctional nanomaterials based on TMPs QDs.
基金the founding support from the National Natural Science Foundation of China(21906072 and 22006057)the Natural Science Foundation of Jiangsu Province(BK20190982)+1 种基金“Doctor of Mass entrepreneurship and innovation”Project in Jiangsu ProvinceDoctoral Scientific Research Foundation of Jiangsu University of Science and Technology(China)(1062931806 and 1142931803)。
文摘Photocatalytic water splitting for hydrogen production(H_(2))is one of the main potential applications of photocatalytic technology,which can use solar energy as the energy required for chemical reactions to alleviate the energy crisis.In this work,zero-dimensional/two-dimensional(0D/2D)contact surface CdS/α-Fe_(2)O_(3)(CF)heterojunction photocatalyst was synthesized via a simple solvothermal method.Photocatalytic hydrogen production experiments revealed that the CF-15 sample shows the optimal photocatalytic H_(2)rate(1806μmol·h^(-1)·g^(-1))and apparent quantum efficiency(AQE=13.7%atλ=420 nm).The enhancement of photocatalytic performance is mainly attributed to the contact of 0D/2D interface and the synergistic effect of Z-scheme electron transfer mechanism.This work provides an effective way for modified composite semiconductor photocatalyst by constructing special interface heterojunction to achieve highly efficiently catalysis.
基金supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2021ME143,ZR2020MA076).
文摘The purposeful construction of dual Z-scheme system to the formation of intimate interface contact and multi-channel charge flow through the system remains a huge challenge.Herein,a tandem 2D/0D/2D g-C_(3)N_(4)nanosheets/FeOOH quantum dots/ZnIn_(2)S_(4)nanosheets(CNFeZn)dual Z-scheme system(DZSS)has been successfully constructed using electrostatic self-assembly method.Owing to the band structure and elaborate morphology of 2D g-C_(3)N_(4),0D FeOOH and 2D ZnIn_(2)S_(4)in unique designed DZSS,plenty of spatial charge transfer channels are formed between the g-C_(3)N_(4)/FeOOH and FeOOH/ZnIn_(2)S_(4)interfaces,which greatly accelerate the charge separation and transfer.As bifunctional catalysts,CNFeZn DZSS achieves the highest H_(2)evolution rate of~436.6 mmol/h with a great promotion of~10.6 folds and~6.9 folds compared to pristine g-C_(3)N_(4)and ZnIn_(2)S_(4),respectively.Meanwhile,the H_(2)O_(2)production rate reached~301.19 mmol/L after 60 min irradiation,up to~5.1 times and~2.3 times that of pristine g-C_(3)N_(4)and ZnIn_(2)S_(4).Experiment and DFT calculation further confirmed that the stable double built-in electronic field can be formed owing to the electron configuration between double interfaces,and reveal that the ample atomic-level charge transfer channels were established in the strong interaction connected double interfaces,which can act as the charge migration pathway promote the separation of photogenerated charges.
