The persistent increase of CO_(2) levels in the atmosphere,already exceeding 400 ppm,urges the exploration of CO_(2) emission reduction and recycling technologies.Ideally,photocatalytic conversion of CO_(2) into valua...The persistent increase of CO_(2) levels in the atmosphere,already exceeding 400 ppm,urges the exploration of CO_(2) emission reduction and recycling technologies.Ideally,photocatalytic conversion of CO_(2) into valuable hydrocarbons realizes solar-to-chemical energy conversion,which is a desirable“kill two birds with one stone”strategy;namely,CO_(2) photoreduction can simultaneously tackle energy shortage and keep global carbon balance.Graphitic carbon nitride(g-C_(3)N_(4))working on CO_(2) reduction reaction deserves a highlight not only for the metal-free feature that endows it with low cost,tunable electronic structure,and easy fabrication properties but also because of its strong reduction ability.The present review concisely summarizes the latest advances of g-C_(3)N_(4)-based photocatalysts toward CO_(2) reduction.It starts with the discussion of thermodynamics and dynamics aspects of the CO_(2) reduction process.Then the modification strategies to promote g-C_(3)N_(4)-based photocatalysts in CO_(2) photoreduction have been discussed in detail,including surface functionalization,molecule structure engineering,crystallization,morphology engineering,loading cocatalyst,and constructing heterojunction.Meanwhile,the intrinsic factors affecting CO_(2) reduction activity and selectivity are analyzed and summarized.In the end,the challenges and prospects for the future development of highly g-C_(3)N_(4)-based photocatalysts in CO_(2) reduction are also presented.展开更多
The catalytic descriptor with operational feasibility is highly desired towards rational design of high-performance catalyst especially the electrode/electrolyte solution interface working under mild conditions.Herein...The catalytic descriptor with operational feasibility is highly desired towards rational design of high-performance catalyst especially the electrode/electrolyte solution interface working under mild conditions.Herein,we demonstrate that the descriptorΩparameterized by readily accessible intrinsic properties of metal center and coordination is highly operational and efficient in rational design of single-atom catalyst(SAC)for driving electrochemical nitrogen reduction(NRR).Using twodimensional metal(M)-B_(x)P_(y)S_(z)N_m@C_(2)N as prototype SAC models,we reveal that^(*)N_(2)+(H~++e~-)→^(*)N_(2)H acts predominantly as the potential-limiting step(PLS)of NRR on M-B_(2)P_(2)S_(2)@C_(2)N and M-B_(1)P_(1)S_(1)N_(3)@C_(2)N regardless of the distinction in coordination microenvironment.Among the 28 screened M active sites,withΩvalues close to the optimal 4,M-B_(2)P_(2)S_(2)@C_(2)N(M=V(Ω=3.53),Mo(Ω=5.12),and W(Ω=3.92))and M-B_(1)P_(1)S_(1)N_(3)@C_(2)N(M=V(Ω=3.00),Mo(Ω=4.34),and W(Ω=3.32))yield the lowered limiting potential(U_(L))as-0.45,-0.54.-0.36,-0.58,-0.25,and-0.24 V,respectively,thus making them the promising NRR catalysts.More importantly,these SACs are located around the top of volcano-shape plot of U_(L) versusΩ,re-validatingΩas an effective descriptor for accurately predicting the high-activity NRR SACs even with complex coordination.Our study unravels the relationship between active-site structure and NRR performance via the descriptorΩ,which can be applied to other important sustainable electrocatalytic reactions involving activation of small molecules viaσ-donation andπ^(*)-backdonation mechanism.展开更多
The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,wh...The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.展开更多
Photocatalytic reduction of CO_(2) is considered as a kind of promising technologies for solving the greenhouse effect.Herein,a novel hybrid structure of g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) photocatalysts was designed and fa...Photocatalytic reduction of CO_(2) is considered as a kind of promising technologies for solving the greenhouse effect.Herein,a novel hybrid structure of g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) photocatalysts was designed and fabricated to investigate their abilities for CO_(2) reduction.As demonstration,heterojunction of g-C_(3)N_(4)/ZnO can improve photogenerated carriers’separation,the addition of Ti_(3)C_(2) fragments can further facilitate the photocatalytic performance from CO_(2) to CO.Hence,g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) has efficiently increased CO production by 8 and 12 times than pristine g-C_(3)N_(4) and ZnO,respectively.Which is ascribed to the photogenerated charge migration promoted by metallic Ti_(3)C_(2).This work provides a guideline for designing efficient hybrid catalysts on other applications in the renewable energy fields.展开更多
Photocatalytic CO_(2)reduction to valuable product exhibit promising prospect for solving the energy crisis and the greenhouse effect.Herein,Co-Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)(Co-TC/CN)composite with enhanced photocatal...Photocatalytic CO_(2)reduction to valuable product exhibit promising prospect for solving the energy crisis and the greenhouse effect.Herein,Co-Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)(Co-TC/CN)composite with enhanced photocatalytic performance for converting CO_(2)to CO and CH_(4)was constructed by electrostatic self-assembly method.The close contact interface between Co-Ti_(3)C_(2)T_(x)and g-C_(3)N_(4)nanosheets can be used as fast transport channels of photogenerated electrons and effectively promote the separation of photogenerated electrons and holes,and the interface between the Co and Ti_(3)C_(2)T_(x)might be the active sites for CO_(2)adsorption and activation.The optimized Co-Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)composite exhibited the highest photocatalytic performance with the CO and CH_(4)production of 55.04 μmol·g^(-1)and 2.29 μmol·g^(-1),respectively,which were 7.5 times and 5.8 times than those of g-C_(3)N_(4).Furthermore,the stability of g-C_(3)N_(4)was improved after coupling with Co-Ti_(3)C_(2)T_(x).展开更多
基金Natural Science Foundation of Xinjiang Province,Grant/Award Numbers:2019D01C064,2020D01A49,2020D01B25,2021D01B40National Natural Science Foundation of China,Grant/Award Numbers:21905209,52072273Tianshan innovation team project of Xinjiang Uygur Autonomous Region,Grant/Award Number:2021D14013。
文摘The persistent increase of CO_(2) levels in the atmosphere,already exceeding 400 ppm,urges the exploration of CO_(2) emission reduction and recycling technologies.Ideally,photocatalytic conversion of CO_(2) into valuable hydrocarbons realizes solar-to-chemical energy conversion,which is a desirable“kill two birds with one stone”strategy;namely,CO_(2) photoreduction can simultaneously tackle energy shortage and keep global carbon balance.Graphitic carbon nitride(g-C_(3)N_(4))working on CO_(2) reduction reaction deserves a highlight not only for the metal-free feature that endows it with low cost,tunable electronic structure,and easy fabrication properties but also because of its strong reduction ability.The present review concisely summarizes the latest advances of g-C_(3)N_(4)-based photocatalysts toward CO_(2) reduction.It starts with the discussion of thermodynamics and dynamics aspects of the CO_(2) reduction process.Then the modification strategies to promote g-C_(3)N_(4)-based photocatalysts in CO_(2) photoreduction have been discussed in detail,including surface functionalization,molecule structure engineering,crystallization,morphology engineering,loading cocatalyst,and constructing heterojunction.Meanwhile,the intrinsic factors affecting CO_(2) reduction activity and selectivity are analyzed and summarized.In the end,the challenges and prospects for the future development of highly g-C_(3)N_(4)-based photocatalysts in CO_(2) reduction are also presented.
基金supported by the National Natural Science Foundation of China (21673137)。
文摘The catalytic descriptor with operational feasibility is highly desired towards rational design of high-performance catalyst especially the electrode/electrolyte solution interface working under mild conditions.Herein,we demonstrate that the descriptorΩparameterized by readily accessible intrinsic properties of metal center and coordination is highly operational and efficient in rational design of single-atom catalyst(SAC)for driving electrochemical nitrogen reduction(NRR).Using twodimensional metal(M)-B_(x)P_(y)S_(z)N_m@C_(2)N as prototype SAC models,we reveal that^(*)N_(2)+(H~++e~-)→^(*)N_(2)H acts predominantly as the potential-limiting step(PLS)of NRR on M-B_(2)P_(2)S_(2)@C_(2)N and M-B_(1)P_(1)S_(1)N_(3)@C_(2)N regardless of the distinction in coordination microenvironment.Among the 28 screened M active sites,withΩvalues close to the optimal 4,M-B_(2)P_(2)S_(2)@C_(2)N(M=V(Ω=3.53),Mo(Ω=5.12),and W(Ω=3.92))and M-B_(1)P_(1)S_(1)N_(3)@C_(2)N(M=V(Ω=3.00),Mo(Ω=4.34),and W(Ω=3.32))yield the lowered limiting potential(U_(L))as-0.45,-0.54.-0.36,-0.58,-0.25,and-0.24 V,respectively,thus making them the promising NRR catalysts.More importantly,these SACs are located around the top of volcano-shape plot of U_(L) versusΩ,re-validatingΩas an effective descriptor for accurately predicting the high-activity NRR SACs even with complex coordination.Our study unravels the relationship between active-site structure and NRR performance via the descriptorΩ,which can be applied to other important sustainable electrocatalytic reactions involving activation of small molecules viaσ-donation andπ^(*)-backdonation mechanism.
基金National Key R&D Program of China,Grant/Award Number:2020YFA0710000National Natural Science Foundation of China,Grant/Award Numbers:22008170,21978200,22161142002,22121004。
文摘The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.
基金supported by National Natural Science Foundation of China(Grant No.11804005,11375136,12204014)Anyang Institute of Technology Research Cultivation Fund(Grant No.YPY2019002)。
文摘Photocatalytic reduction of CO_(2) is considered as a kind of promising technologies for solving the greenhouse effect.Herein,a novel hybrid structure of g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) photocatalysts was designed and fabricated to investigate their abilities for CO_(2) reduction.As demonstration,heterojunction of g-C_(3)N_(4)/ZnO can improve photogenerated carriers’separation,the addition of Ti_(3)C_(2) fragments can further facilitate the photocatalytic performance from CO_(2) to CO.Hence,g-C_(3)N_(4)/ZnO/Ti_(3)C_(2) has efficiently increased CO production by 8 and 12 times than pristine g-C_(3)N_(4) and ZnO,respectively.Which is ascribed to the photogenerated charge migration promoted by metallic Ti_(3)C_(2).This work provides a guideline for designing efficient hybrid catalysts on other applications in the renewable energy fields.
基金the National Natural Science Foundation of China(22208065)Guangxi Natural Science Foundation(2022GXNSFBA035483,2020GXNSFDA297007)+1 种基金Opening Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(2021K009,2020K002)Special funding for‘Guangxi Bagui Scholars’.
文摘Photocatalytic CO_(2)reduction to valuable product exhibit promising prospect for solving the energy crisis and the greenhouse effect.Herein,Co-Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)(Co-TC/CN)composite with enhanced photocatalytic performance for converting CO_(2)to CO and CH_(4)was constructed by electrostatic self-assembly method.The close contact interface between Co-Ti_(3)C_(2)T_(x)and g-C_(3)N_(4)nanosheets can be used as fast transport channels of photogenerated electrons and effectively promote the separation of photogenerated electrons and holes,and the interface between the Co and Ti_(3)C_(2)T_(x)might be the active sites for CO_(2)adsorption and activation.The optimized Co-Ti_(3)C_(2)T_(x)/g-C_(3)N_(4)composite exhibited the highest photocatalytic performance with the CO and CH_(4)production of 55.04 μmol·g^(-1)and 2.29 μmol·g^(-1),respectively,which were 7.5 times and 5.8 times than those of g-C_(3)N_(4).Furthermore,the stability of g-C_(3)N_(4)was improved after coupling with Co-Ti_(3)C_(2)T_(x).
