Reducing nitrogen to ammonia with solar energy has become a wide concern when it comes to photocatalysis research.It is considered to be one of the more promising alternate options for the conventional Haber-Bosch cyc...Reducing nitrogen to ammonia with solar energy has become a wide concern when it comes to photocatalysis research.It is considered to be one of the more promising alternate options for the conventional Haber-Bosch cycle.Herein,2D g-C_(3)N_(4)composites with modifying ultrathin sheet MnO_(2-x)were prepared and used as nitrogen fixation photocatalyst.With the assistance of the nature of MnO_(2-x),the generation rate of NH_(3)reached 225 mmol g^(-1)h^(-1),which is more than twice over the rate of pristine 2D g-C_(3)N_(4)(107 mmol g^(-1)h^(-1)).The presence of ultrathin sheet MnO_(2-x)shortens the gap of the carriers to the surface of photocatalyst.Thus the speed of electron transfer gets increased.Besides,the construction of Z-scheme heterojunction boosts the separation and migration of photogenerated carriers.As a result,the nitrogen reduction reaction(NRR)performance gets enhanced.The work may provide an example of promoting the NRR performance of non-metallic compound.展开更多
Hematite is regarded as a promising photoanode for photoelectrochemical(PEC) water splitting.However,the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite.H...Hematite is regarded as a promising photoanode for photoelectrochemical(PEC) water splitting.However,the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite.Herein,we reported a Ti3C2 MXene underlayer modified hematite(Ti-Fe2O3) photoanode via a simple drop-casting followed by hydrothermal and annealing processes.Owing to the bifunctional role of Ti3C2 MXene underlayer in improving the interfacial properties of FTO/hematite and providing Ti source for the construction of Fe2 TiO5/Fe2O3 heterostructure in hematite nanostructure,the bulk and interfacial charge transfer dynamics of hematite are significantly enhanced,and consequently enhancing the PEC performance.Compared with the pristine hematite,the as-prepared Ti-Fe2O3 photoanode shows an increased photocurrent density from 0.80 mA/cm^(2) to 1.30 mA/cm^(2) at 1.23 V vs.RHE.Moreover,a further promoted PEC performance including a dramatically increased photocurrent density of 2.49 mA/cm^(2) at1.23 V vs.RHE and an obviously lowered onset potential is achieved for the Ti-Fe2O3 sample after the subsequent surface F-treatment and the loading of FeNiOOH cocatalyst.Such results suggest that the introduction of Ti3C2 MXene underlayer is a facile but effective approach to improve the PEC water splitting activity of hematite.展开更多
Ammonia plays a vital role in the development of modern agriculture and industry.Compared to the conventional Haber–Bosch ammonia synthesis in industry,electrocatalytic nitrogen reduction reaction(NRR)is considered a...Ammonia plays a vital role in the development of modern agriculture and industry.Compared to the conventional Haber–Bosch ammonia synthesis in industry,electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising and environmental friendly strategy to synthesize ammonia.Here,inspired by biological nitrogenase,we designed iron doped tin oxide(Fe-doped SnO_(2))for nitrogen reduction.In this work,iron can optimize the interface electron transfer and improve the poor conductivity of the pure SnO_(2),meanwhile,the synergistic effect between iron and Sn ions improves the catalyst activity.In the electrocatalytic NRR test,Fe-doped SnO_(2) exhibits a NH_(3) yield of 28.45μg·h^(−1)·mgcat^(−1),which is 2.1 times that of pure SnO_(2),and Faradaic efficiency of 6.54%at−0.8 V vs.RHE in 0.1 M Na_(2)SO_(4).It also shows good stability during a 12-h long-term stability test.Density functional theory calculations show that doped Fe atoms in SnO_(2) enhance catalysis performance of some Sn sites by strengthening N–Sn interaction and lowering the energy barrier of the rate-limiting step of NRR.The transient photovoltage test reveals that electrons in the low-frequency region are the key to determining the electron transfer ability of Fe-doped SnO_(2).展开更多
Photo/electrocatalytic water splitting has been considered as one of the most promising approaches for the clean hydrogen production. Among various photo/electrocatalysts,2D nanomaterials exhibit great potential becau...Photo/electrocatalytic water splitting has been considered as one of the most promising approaches for the clean hydrogen production. Among various photo/electrocatalysts,2D nanomaterials exhibit great potential because of their conspicuous properties. Meanwhile,synchrotron-based soft X-ray absorption spectroscopy(XAS) as a powerful and element-specific technique has been widely used to explore the electronic structure of 2D photo/electrocatalysts to comprehensively understand their working mechanism for the development of high-performance catalysts. In this work, the recent developments of soft XAS techniques applied in 2D photo/electrocatalysts have been reviewed, mainly focusing on identifying the surface active sites,elucidating the location of heteroatoms, and unraveling the interfacial interaction in the composite.The challenges and outlook in this research field have also been emphasized. The present review provides an in-depth understanding on how soft XAS techniques unravel the correlations between structure and performance in 2D photo/electrocatalysts, which could guide the rational design of highly efficient catalysts for photo/electrocatalytic water splitting.展开更多
基金supported by National Natural Science Foundation of China(21776118,21808090)Natural Science Foundation of Jiangsu Province(BK20190981)+3 种基金Jiangsu Fund for Distinguished Young Scientists(BK20190045)China Postdoctoral Science Foundation(2019M661765)High-tech Research Key laboratory of Zhenjiang(SS2018002)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,the high-performance computing platform of Jiangsu University。
文摘Reducing nitrogen to ammonia with solar energy has become a wide concern when it comes to photocatalysis research.It is considered to be one of the more promising alternate options for the conventional Haber-Bosch cycle.Herein,2D g-C_(3)N_(4)composites with modifying ultrathin sheet MnO_(2-x)were prepared and used as nitrogen fixation photocatalyst.With the assistance of the nature of MnO_(2-x),the generation rate of NH_(3)reached 225 mmol g^(-1)h^(-1),which is more than twice over the rate of pristine 2D g-C_(3)N_(4)(107 mmol g^(-1)h^(-1)).The presence of ultrathin sheet MnO_(2-x)shortens the gap of the carriers to the surface of photocatalyst.Thus the speed of electron transfer gets increased.Besides,the construction of Z-scheme heterojunction boosts the separation and migration of photogenerated carriers.As a result,the nitrogen reduction reaction(NRR)performance gets enhanced.The work may provide an example of promoting the NRR performance of non-metallic compound.
基金the support from the high-performance computing platform of Jiangsu UniversityThe Jiangsu University Foundation (18JDG019)+3 种基金the Postdoctoral Foundation of Jiangsu Province (2018K072C)Six Talent Peak Project of Jiangsu Province (XLC-158)the China Postdoctoral Science Foundation (2019M651727, 2019M651719)the National Natural Science Foundation of China (21808090, 51902139, U1932211) financially supported this work。
文摘Hematite is regarded as a promising photoanode for photoelectrochemical(PEC) water splitting.However,the charge recombination occurred at the interface of FTO/hematite strictly limits the PEC performance of hematite.Herein,we reported a Ti3C2 MXene underlayer modified hematite(Ti-Fe2O3) photoanode via a simple drop-casting followed by hydrothermal and annealing processes.Owing to the bifunctional role of Ti3C2 MXene underlayer in improving the interfacial properties of FTO/hematite and providing Ti source for the construction of Fe2 TiO5/Fe2O3 heterostructure in hematite nanostructure,the bulk and interfacial charge transfer dynamics of hematite are significantly enhanced,and consequently enhancing the PEC performance.Compared with the pristine hematite,the as-prepared Ti-Fe2O3 photoanode shows an increased photocurrent density from 0.80 mA/cm^(2) to 1.30 mA/cm^(2) at 1.23 V vs.RHE.Moreover,a further promoted PEC performance including a dramatically increased photocurrent density of 2.49 mA/cm^(2) at1.23 V vs.RHE and an obviously lowered onset potential is achieved for the Ti-Fe2O3 sample after the subsequent surface F-treatment and the loading of FeNiOOH cocatalyst.Such results suggest that the introduction of Ti3C2 MXene underlayer is a facile but effective approach to improve the PEC water splitting activity of hematite.
基金supported by the National Natural Science Foundation of China(Nos.51802126 and 52072152)the Jiangsu University Jinshan Professor Fund and the Jiangsu SpeciallyAppointed Professor Fund,Open Fund from Guangxi Key Laboratory of Electrochemical Energy Materials,and the Science and Technology Planning Social Development Project of Zhenjiang City(No.SH2019010).
文摘Ammonia plays a vital role in the development of modern agriculture and industry.Compared to the conventional Haber–Bosch ammonia synthesis in industry,electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising and environmental friendly strategy to synthesize ammonia.Here,inspired by biological nitrogenase,we designed iron doped tin oxide(Fe-doped SnO_(2))for nitrogen reduction.In this work,iron can optimize the interface electron transfer and improve the poor conductivity of the pure SnO_(2),meanwhile,the synergistic effect between iron and Sn ions improves the catalyst activity.In the electrocatalytic NRR test,Fe-doped SnO_(2) exhibits a NH_(3) yield of 28.45μg·h^(−1)·mgcat^(−1),which is 2.1 times that of pure SnO_(2),and Faradaic efficiency of 6.54%at−0.8 V vs.RHE in 0.1 M Na_(2)SO_(4).It also shows good stability during a 12-h long-term stability test.Density functional theory calculations show that doped Fe atoms in SnO_(2) enhance catalysis performance of some Sn sites by strengthening N–Sn interaction and lowering the energy barrier of the rate-limiting step of NRR.The transient photovoltage test reveals that electrons in the low-frequency region are the key to determining the electron transfer ability of Fe-doped SnO_(2).
基金financially supported by National Key R&D Program of China (2020YFA0406103)China Postdoctoral Science Foundation (2020T130754)National Natural Science Foundation of China (51902139, U1932211)。
文摘Photo/electrocatalytic water splitting has been considered as one of the most promising approaches for the clean hydrogen production. Among various photo/electrocatalysts,2D nanomaterials exhibit great potential because of their conspicuous properties. Meanwhile,synchrotron-based soft X-ray absorption spectroscopy(XAS) as a powerful and element-specific technique has been widely used to explore the electronic structure of 2D photo/electrocatalysts to comprehensively understand their working mechanism for the development of high-performance catalysts. In this work, the recent developments of soft XAS techniques applied in 2D photo/electrocatalysts have been reviewed, mainly focusing on identifying the surface active sites,elucidating the location of heteroatoms, and unraveling the interfacial interaction in the composite.The challenges and outlook in this research field have also been emphasized. The present review provides an in-depth understanding on how soft XAS techniques unravel the correlations between structure and performance in 2D photo/electrocatalysts, which could guide the rational design of highly efficient catalysts for photo/electrocatalytic water splitting.