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
An S-scheme heterojunction photocatalyst is capable of boosting photogenerated carrier separation and transfer,thus maintaining high photooxidation and photoredox ability.Herein,a 0D Ag_(3)PO_(4) nanoparticles(NPs)/1D...An S-scheme heterojunction photocatalyst is capable of boosting photogenerated carrier separation and transfer,thus maintaining high photooxidation and photoredox ability.Herein,a 0D Ag_(3)PO_(4) nanoparticles(NPs)/1D TiO_(2) nanofibers(NFs)S-scheme heterojunction with intimate interfacial contact was designed via the the hydro-thermal method.Benefiting from the abundant hydroxyl groups and size confinement effect of TiO_(2) NFs,the average diameter of the Ag_(3)PO_(4) nanoparticles decreased from 100 to 22 nm,which favored the construction of a 0D/1D geometry heterojunction.The multifunctional Ag_(3)PO_(4)/TiO_(2) sample exhibited excellent photocatalytic activity and stability in photocatalytic oxygen production(726μmol/g/h)and photocatalytic degradation of various organic contaminants such as rhodamine B(100%),phenol(60%)and tetracycline hydrochloride(100%).The significant improvements in the photocatalytic performance and stability can be attributed to the intimate interfacial contacts and rich active sites of 0D/1D geometry,fast charge carrier migration,and outstanding photoredox properties induced by the S-scheme charge-transfer route.This work offers a promising strategy for constructing 0D/1D S-scheme heterojunction photocatalysts for improved photocatalytic performance.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
MXenes,a new family of two-dimensional(2D)materials with excellent electronic conductivity and hydrophilicity,have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes.Her...MXenes,a new family of two-dimensional(2D)materials with excellent electronic conductivity and hydrophilicity,have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes.Herein,a facile electrostatic self-assembly of SnO2 quantum dots(QDs)on Ti3C2Tx MXene sheets is proposed.The as-prepared SnO2/MXene hybrids have a unique 0D-2D structure,in which the 0D SnO2 QDs(~4.7 nm)are uniformly distributed over 2D Ti3C2Tx MXene sheets with controllable loading amount.The SnO2 QDs serve as a high capacity provider and the“spacer”to prevent the MXene sheets from restacking;the highly conductive Ti3C2Tx MXene can not only provide efficient pathways for fast transport of electrons and Li ions,but also buffer the volume change of SnO2 during lithiation/delithiation by confining SnO2 QDs between the MXene nanosheets.Therefore,the 0D-2D SnO2 QDs/MXene hybrids deliver superior lithium storage properties with high capacity(887.4 mAh g?1 at 50 mA g?1),stable cycle performance(659.8 mAh g?1 at 100 mA g?1 after 100 cycles with a capacity retention of 91%)and excellent rate performance(364 mAh g?1 at 3 A g?1),making it a promising anode material for lithium-ion batteries.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
Graphite‐like carbon nitride(g‐C3N4)‐based compounds have attracted considerable attention because of their excellent photocatalytic performance.In this work,a novel direct Z‐scheme system constructed from two‐di...Graphite‐like carbon nitride(g‐C3N4)‐based compounds have attracted considerable attention because of their excellent photocatalytic performance.In this work,a novel direct Z‐scheme system constructed from two‐dimensional(2D)g‐C3N4nanoplates and zero‐dimensional(0D)MoS2quantum dots(QDs)was prepared through the combination of a hydrothermal process and microemulsion preparation.The morphologies,structures,and optical properties of the as‐prepared photocatalysts were characterized by X‐ray diffraction,X‐ray photoelectron spectroscopy,atomic force microscopy,transmission electron microscopy,and UV‐vis diffuse reflectance spectroscopy.In addition,the photocatalytic performances of the prepared2D/0D hybrid composites were evaluated based on the photodegradation of rhodamine B under visible‐light irradiation.The results demonstrated that the introduction of MoS2QDs to g‐C3N4greatly enhanced the photocatalytic efficiency.For the optimum7%MoS2QD/g‐C3N4photocatalyst,the degradation rate constant was8.8times greater than that of pure g‐C3N4under visible‐light irradiation.Photocurrent and electrochemical impedance spectroscopy results further demonstrated that the MoS2QD/g‐C3N4composites exhibited higher photocurrent density and lower chargetransfer resistance than those of the pure g‐C3N4or MoS2QDs.Active species trapping,terephthalic acid photoluminescence,and nitro blue tetrazolium transformation experiments were performed to investigate the evolution of reactive oxygen species,including hydroxyl radicals and superoxide radicals.The possible enhanced photocatalytic mechanism was attributed to a direct Z‐scheme system,which not only can increase the separation efficiency of photogenerated electron‐hole pairs but also possesses excellent oxidation and reduction ability for high photocatalytic performances.This work provides an effective synthesis approach and insight to help develop other C3N4‐based direct Z‐scheme photocatalytic systems for environmental purification and energy conversion.展开更多
Low dimension nano photocatalysts show great potential in the field of treating contaminated water for their large surface area and size effect.In this study,a 0 D/1 D AgI/MoO_(3)Z-scheme photocatalyst with striking p...Low dimension nano photocatalysts show great potential in the field of treating contaminated water for their large surface area and size effect.In this study,a 0 D/1 D AgI/MoO_(3)Z-scheme photocatalyst with striking photocatalytic performance was constructed successfully.The one-dimensional MoO_(3)nanobelts were prepared by a simple hydrothermal method,and then it was modified by AgI nanoparticles in a handy deposition approach.When choosing sulfamethoxazole(SMZ)as the target contaminant,the rate constant value of the optimal 0 D/1 D AgI/MoO_(3)composite could hit up to 0.13 min^(-1),which is nearly 22.4 times and 32.5 times as that of pure MoO_(3)(0.0058 min^(-1))and AgI(0.0040 min^(-1)),respectively.A series of detailed characterizations give evidences that the charge transfer in the composite followed Z scheme mechanism.Therefore,efficient separation/transfer and the remained high redox activity of photogenerated carriers played a vital role in the sharply enhanced photocatalytic properties.The possible degradation pathways of SMZ were proposed based on the intermediates detected by high-performance liquid chromatography-mass spectrometry(HPLC-MS).Meanwhile,the magnificent cyclic stability makes the material a promising material in the practical application.展开更多
A 3D/0D cobalt-embedded nitrogen-doped porous carbon nanocubes(Co-N-C)/supramolecular tetra(4-carboxylphenyl)porphyrin nanocrystals(SA-TCPP)photocatalyst was successfully self-assembled viaπ–πinteraction,hydrogen b...A 3D/0D cobalt-embedded nitrogen-doped porous carbon nanocubes(Co-N-C)/supramolecular tetra(4-carboxylphenyl)porphyrin nanocrystals(SA-TCPP)photocatalyst was successfully self-assembled viaπ–πinteraction,hydrogen bonding,and chemical bonding.Co-N-C/SA-TCPP heterostructure exhibited satisfactory visible photocatalytic oxidation performance on pollutant degradation and water evolution.The degradation rates of Co-N-C/ST(30%)composite towards 2,4-dichlorophenol,ofloxacin,and ethylene were10.9,7.2,and 2.1 times faster than SA-TCPP,respectively.The oxygen evolution efficiency was 1.9 times higher than SA-TCPP.The remarkably improved oxidation activities of Co-N-C/SA-TCPP were mainly ascribed to the following reasons:(1)Co-N-C could enhance the light absorption ability of SA-TCPP to produce more photoinduced carriers.(2)The well-developed porosity of Co-N-C could optimize the dispersibility of SA-TCPP to provide more reactive sites and charge separation channels.(3)Theπ–πinteraction between SA-TCPP and Co-N-C was beneficial to interlayer charge mobility,while the embedded cobalt nanoparticles(Co NPs)and N-doped carbon matrix could serve as electron traps to accelerate interfacial electron transfer.Additionally,the ferromagnetic Co NPs endowed Co-N-C/SA-TCPP with magnetic-separation function to promote recyclability in practical application.展开更多
Diesel engines have proven over the years important in terms of efficiency and fuel consumption to power generation ratio. Many research works show the potential of biodiesel as a substitute for conventional gasoil. M...Diesel engines have proven over the years important in terms of efficiency and fuel consumption to power generation ratio. Many research works show the potential of biodiesel as a substitute for conventional gasoil. Mainly, previous and recent researches have focused on experimental investigation of diesel engine performance fuelled by biodiesel. Researches on the mathematical description of diesel engine process running on biodiesel are scarce, and mostly about chemical and thermodynamic description of the combustion process of biodiesel rather than performance studies. This work describes a numerical investigation on the performance analysis of a diesel engine fuelled by palm oil biodiesel. The numerical investigation was made using a semi empirical 0D model based on Wiebe’s and Watson’s model which was implemented via the open access numerical calculation software Scilab. The model was validated first by comparing with experimental pressure and performance data of a one cylinder engine at rated speed and secondly by comparing with a six cylinders engine performance data at various crankshaft rotational speeds. Simulations were then made to analyze the engine performance when running on biodiesel. The calculations were made at constant combustion duration and constant coefficient of excess air. Results showed that the model matches the overall experimental data, such as the power output and peak cylinder pressure. The ignition delay was somehow underestimated by the model for the first experiment, which caused a slight gap on in cylinder pressure curve, whereas it predicted the average ignition delay fairly well for the second set of validation. The simulations of engine performance when running on biodiesel confirmed results obtained in previous experimental researches on biodiesel. The model will be further investigated for engine control when shifting to biodiesel fuel.展开更多
Herein,a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots(MSQDs)and 3D honeycomb-like conjugated triazine polymers(CTP)(namely,CTP-MSQD).The unique 0D/3D hierarchical struc...Herein,a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots(MSQDs)and 3D honeycomb-like conjugated triazine polymers(CTP)(namely,CTP-MSQD).The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property,while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators.The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI)reduction and H2 evolution,featured a rate of 0.069 min^(-1) and 1070μmol/(hr•g),respectively,which were 8 times than those of pure 3D-CTP(0.009 min^(−1) and 129μmol/(hr•g)).We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.展开更多
Designing and fabricating highly efficient photocatalysts for water splitting is a promising strategy to address energy and environmental issues.Cadmium sulfide(CdS)has received significant interest as a photocatalyst...Designing and fabricating highly efficient photocatalysts for water splitting is a promising strategy to address energy and environmental issues.Cadmium sulfide(CdS)has received significant interest as a photocatalyst for visible‐light‐induced hydrogen(H2)generation.However,the severe photocorrosion,high overpotential,rapid charge recombination,and sluggish surface reaction kinetics drastically hinder its practical application in water splitting.Herein,uniform zinc cadmium sulfide(Zn_(0.5)Cd_(0.5)S)nanoparticles were anchored on ultrathin Ni(OH)_(2)nanosheets via a facile solution‐phase approach to form an intimate two‐dimensional(2D)/zero‐dimensional(0D)heterojunction.Under visible light irradiation,the 7%Ni(OH)_(2)/Zn_(0.5)Cd_(0.5)S composite exhibited the highest H2 production rate of 6.87 mmol·h^(–1)·g^(–1)with an apparent quantum yield of 16.8%at 420 nm,which is almost 43 times higher than that of pristine Zn_(0.5)Cd_(0.5)S and considerably higher than that of the Pt/Zn_(0.5)Cd_(0.5)S photocatalyst.The high photoactivity of the 2D/0D Ni(OH)_(2)/Zn_(0.5)Cd_(0.5)S heterojunction can be ascribed to its unique and robust structure,wherein the ultrathin Ni(OH)_(2)nanosheets not only provide an excellent platform for the incorporation of Zn_(0.5)Cd_(0.5)S nanoparticles but also serve as an effective cocatalyst to promote photoinduced electron transfer and offer more active sites for photocatalytic H_(2) generation.This work paves the way toward the development of versatile,low‐cost,and highly efficient 2D/0D heterojunction photocatalysts for solar energy conversion.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.
文摘An S-scheme heterojunction photocatalyst is capable of boosting photogenerated carrier separation and transfer,thus maintaining high photooxidation and photoredox ability.Herein,a 0D Ag_(3)PO_(4) nanoparticles(NPs)/1D TiO_(2) nanofibers(NFs)S-scheme heterojunction with intimate interfacial contact was designed via the the hydro-thermal method.Benefiting from the abundant hydroxyl groups and size confinement effect of TiO_(2) NFs,the average diameter of the Ag_(3)PO_(4) nanoparticles decreased from 100 to 22 nm,which favored the construction of a 0D/1D geometry heterojunction.The multifunctional Ag_(3)PO_(4)/TiO_(2) sample exhibited excellent photocatalytic activity and stability in photocatalytic oxygen production(726μmol/g/h)and photocatalytic degradation of various organic contaminants such as rhodamine B(100%),phenol(60%)and tetracycline hydrochloride(100%).The significant improvements in the photocatalytic performance and stability can be attributed to the intimate interfacial contacts and rich active sites of 0D/1D geometry,fast charge carrier migration,and outstanding photoredox properties induced by the S-scheme charge-transfer route.This work offers a promising strategy for constructing 0D/1D S-scheme heterojunction photocatalysts for improved photocatalytic performance.
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supported by the National Key Research and Development Program of China“New Energy Project for Electric Vehicle”(2016YFB0100204)the National Natural Science Foundation of China(Nos.51772030,21805011,51572011,51802012)+2 种基金the Joint Funds of the National Natural Science Foundation of China(U1564206)Beijing Key Research and Development Plan(Z181100004518001)China Postdoctoral Science Foundation(Nos.2017M620637,2018M643697,2019T120930).
文摘MXenes,a new family of two-dimensional(2D)materials with excellent electronic conductivity and hydrophilicity,have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes.Herein,a facile electrostatic self-assembly of SnO2 quantum dots(QDs)on Ti3C2Tx MXene sheets is proposed.The as-prepared SnO2/MXene hybrids have a unique 0D-2D structure,in which the 0D SnO2 QDs(~4.7 nm)are uniformly distributed over 2D Ti3C2Tx MXene sheets with controllable loading amount.The SnO2 QDs serve as a high capacity provider and the“spacer”to prevent the MXene sheets from restacking;the highly conductive Ti3C2Tx MXene can not only provide efficient pathways for fast transport of electrons and Li ions,but also buffer the volume change of SnO2 during lithiation/delithiation by confining SnO2 QDs between the MXene nanosheets.Therefore,the 0D-2D SnO2 QDs/MXene hybrids deliver superior lithium storage properties with high capacity(887.4 mAh g?1 at 50 mA g?1),stable cycle performance(659.8 mAh g?1 at 100 mA g?1 after 100 cycles with a capacity retention of 91%)and excellent rate performance(364 mAh g?1 at 3 A g?1),making it a promising anode material for lithium-ion batteries.
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supported by National Natural Science Foundation of China(51672113)Six Talent Peaks Project in Jiangsu Province(2015-XCL-026)+3 种基金Natural Science Foundation of Jiangsu Province(BK20171299)State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE-KF201705),Fuzhou UniversityState Key Laboratory of Advanced Technology for Materials Synthesis and Processing(2016-KF-10),Wuhan University of Technologythe Qing Lan Project Foundation of Jiangsu Province~~
文摘Graphite‐like carbon nitride(g‐C3N4)‐based compounds have attracted considerable attention because of their excellent photocatalytic performance.In this work,a novel direct Z‐scheme system constructed from two‐dimensional(2D)g‐C3N4nanoplates and zero‐dimensional(0D)MoS2quantum dots(QDs)was prepared through the combination of a hydrothermal process and microemulsion preparation.The morphologies,structures,and optical properties of the as‐prepared photocatalysts were characterized by X‐ray diffraction,X‐ray photoelectron spectroscopy,atomic force microscopy,transmission electron microscopy,and UV‐vis diffuse reflectance spectroscopy.In addition,the photocatalytic performances of the prepared2D/0D hybrid composites were evaluated based on the photodegradation of rhodamine B under visible‐light irradiation.The results demonstrated that the introduction of MoS2QDs to g‐C3N4greatly enhanced the photocatalytic efficiency.For the optimum7%MoS2QD/g‐C3N4photocatalyst,the degradation rate constant was8.8times greater than that of pure g‐C3N4under visible‐light irradiation.Photocurrent and electrochemical impedance spectroscopy results further demonstrated that the MoS2QD/g‐C3N4composites exhibited higher photocurrent density and lower chargetransfer resistance than those of the pure g‐C3N4or MoS2QDs.Active species trapping,terephthalic acid photoluminescence,and nitro blue tetrazolium transformation experiments were performed to investigate the evolution of reactive oxygen species,including hydroxyl radicals and superoxide radicals.The possible enhanced photocatalytic mechanism was attributed to a direct Z‐scheme system,which not only can increase the separation efficiency of photogenerated electron‐hole pairs but also possesses excellent oxidation and reduction ability for high photocatalytic performances.This work provides an effective synthesis approach and insight to help develop other C3N4‐based direct Z‐scheme photocatalytic systems for environmental purification and energy conversion.
基金financially supported by the National Key Plan for Research and Development of China(No.2016YFC0502203)Natural Science Foundation of China(No.51979081)+3 种基金Fundamental Research Funds for the Central Universities(No.B200202103)National Science Funds for Creative Research Groups of China(No.51421006)the Key Program of National Natural Science Foundation of China(No.91647206)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Low dimension nano photocatalysts show great potential in the field of treating contaminated water for their large surface area and size effect.In this study,a 0 D/1 D AgI/MoO_(3)Z-scheme photocatalyst with striking photocatalytic performance was constructed successfully.The one-dimensional MoO_(3)nanobelts were prepared by a simple hydrothermal method,and then it was modified by AgI nanoparticles in a handy deposition approach.When choosing sulfamethoxazole(SMZ)as the target contaminant,the rate constant value of the optimal 0 D/1 D AgI/MoO_(3)composite could hit up to 0.13 min^(-1),which is nearly 22.4 times and 32.5 times as that of pure MoO_(3)(0.0058 min^(-1))and AgI(0.0040 min^(-1)),respectively.A series of detailed characterizations give evidences that the charge transfer in the composite followed Z scheme mechanism.Therefore,efficient separation/transfer and the remained high redox activity of photogenerated carriers played a vital role in the sharply enhanced photocatalytic properties.The possible degradation pathways of SMZ were proposed based on the intermediates detected by high-performance liquid chromatography-mass spectrometry(HPLC-MS).Meanwhile,the magnificent cyclic stability makes the material a promising material in the practical application.
基金the Jiangsu Agriculture Science and Technology Innovation Fund(No.CX(20)3108)the National Natural Science Foundation of China(Nos.21707052,31871881,21908079,and 22172065)+3 种基金the Fundamental Research Funds for the Central Universities(No.JUSRP11905)the Key Research and Development Program of Jiangsu Province(No.BE2017623)the Natural Science Foundation of Jiangsu Province(Nos.BK20211239 and BK20201345)the National First-class Discipline Program of Food Science and Technology(No.JUFSTR20180303)。
文摘A 3D/0D cobalt-embedded nitrogen-doped porous carbon nanocubes(Co-N-C)/supramolecular tetra(4-carboxylphenyl)porphyrin nanocrystals(SA-TCPP)photocatalyst was successfully self-assembled viaπ–πinteraction,hydrogen bonding,and chemical bonding.Co-N-C/SA-TCPP heterostructure exhibited satisfactory visible photocatalytic oxidation performance on pollutant degradation and water evolution.The degradation rates of Co-N-C/ST(30%)composite towards 2,4-dichlorophenol,ofloxacin,and ethylene were10.9,7.2,and 2.1 times faster than SA-TCPP,respectively.The oxygen evolution efficiency was 1.9 times higher than SA-TCPP.The remarkably improved oxidation activities of Co-N-C/SA-TCPP were mainly ascribed to the following reasons:(1)Co-N-C could enhance the light absorption ability of SA-TCPP to produce more photoinduced carriers.(2)The well-developed porosity of Co-N-C could optimize the dispersibility of SA-TCPP to provide more reactive sites and charge separation channels.(3)Theπ–πinteraction between SA-TCPP and Co-N-C was beneficial to interlayer charge mobility,while the embedded cobalt nanoparticles(Co NPs)and N-doped carbon matrix could serve as electron traps to accelerate interfacial electron transfer.Additionally,the ferromagnetic Co NPs endowed Co-N-C/SA-TCPP with magnetic-separation function to promote recyclability in practical application.
文摘Diesel engines have proven over the years important in terms of efficiency and fuel consumption to power generation ratio. Many research works show the potential of biodiesel as a substitute for conventional gasoil. Mainly, previous and recent researches have focused on experimental investigation of diesel engine performance fuelled by biodiesel. Researches on the mathematical description of diesel engine process running on biodiesel are scarce, and mostly about chemical and thermodynamic description of the combustion process of biodiesel rather than performance studies. This work describes a numerical investigation on the performance analysis of a diesel engine fuelled by palm oil biodiesel. The numerical investigation was made using a semi empirical 0D model based on Wiebe’s and Watson’s model which was implemented via the open access numerical calculation software Scilab. The model was validated first by comparing with experimental pressure and performance data of a one cylinder engine at rated speed and secondly by comparing with a six cylinders engine performance data at various crankshaft rotational speeds. Simulations were then made to analyze the engine performance when running on biodiesel. The calculations were made at constant combustion duration and constant coefficient of excess air. Results showed that the model matches the overall experimental data, such as the power output and peak cylinder pressure. The ignition delay was somehow underestimated by the model for the first experiment, which caused a slight gap on in cylinder pressure curve, whereas it predicted the average ignition delay fairly well for the second set of validation. The simulations of engine performance when running on biodiesel confirmed results obtained in previous experimental researches on biodiesel. The model will be further investigated for engine control when shifting to biodiesel fuel.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (No. LR21E080001)the National Natural Science Foundation of China (Nos. 21876156, 52000158, 22076168)+1 种基金the Zhejiang Provincial Ten Thousand Talent Program (No. 2018R52013)the Key Research and Development Plan of Zhajiang Province (No. 2021C03176)
文摘Herein,a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots(MSQDs)and 3D honeycomb-like conjugated triazine polymers(CTP)(namely,CTP-MSQD).The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property,while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators.The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI)reduction and H2 evolution,featured a rate of 0.069 min^(-1) and 1070μmol/(hr•g),respectively,which were 8 times than those of pure 3D-CTP(0.009 min^(−1) and 129μmol/(hr•g)).We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.
文摘Designing and fabricating highly efficient photocatalysts for water splitting is a promising strategy to address energy and environmental issues.Cadmium sulfide(CdS)has received significant interest as a photocatalyst for visible‐light‐induced hydrogen(H2)generation.However,the severe photocorrosion,high overpotential,rapid charge recombination,and sluggish surface reaction kinetics drastically hinder its practical application in water splitting.Herein,uniform zinc cadmium sulfide(Zn_(0.5)Cd_(0.5)S)nanoparticles were anchored on ultrathin Ni(OH)_(2)nanosheets via a facile solution‐phase approach to form an intimate two‐dimensional(2D)/zero‐dimensional(0D)heterojunction.Under visible light irradiation,the 7%Ni(OH)_(2)/Zn_(0.5)Cd_(0.5)S composite exhibited the highest H2 production rate of 6.87 mmol·h^(–1)·g^(–1)with an apparent quantum yield of 16.8%at 420 nm,which is almost 43 times higher than that of pristine Zn_(0.5)Cd_(0.5)S and considerably higher than that of the Pt/Zn_(0.5)Cd_(0.5)S photocatalyst.The high photoactivity of the 2D/0D Ni(OH)_(2)/Zn_(0.5)Cd_(0.5)S heterojunction can be ascribed to its unique and robust structure,wherein the ultrathin Ni(OH)_(2)nanosheets not only provide an excellent platform for the incorporation of Zn_(0.5)Cd_(0.5)S nanoparticles but also serve as an effective cocatalyst to promote photoinduced electron transfer and offer more active sites for photocatalytic H_(2) generation.This work paves the way toward the development of versatile,low‐cost,and highly efficient 2D/0D heterojunction photocatalysts for solar energy conversion.
