Photoelectrochemical(PEC)water-splitting using solar energy holds great promise for the renewable energy future,and a key challenge in the development of industry viable PEC devices is the unavailability of high-effic...Photoelectrochemical(PEC)water-splitting using solar energy holds great promise for the renewable energy future,and a key challenge in the development of industry viable PEC devices is the unavailability of high-efficient photoanodes.Herein,we designed a TiO_(2) model photocatalyst with nano-groove pattern and different surface orientation using low-energy Ar+irradiation and photoetching of TiO_(2),and significantly improved the intrinsic activity for PEC water oxidation.High-resolution transmission electron microscopy directly manifests that the grooves consist of highly stepped surface with<110>steps and well-crystallized.Transient absorption spectroscopy reveals the groove surface that allows for increased recovery lifetime,which ensures promoted electron-hole separation efficiency.Surface photovoltage directly shows the carrier separation and transportation behaviors,verified by selective photodeposition,demonstrating the groove surface on TiO_(2) contributes to electron-hole separation.This work proposes an efficient and scalable photoanode strategy,which potentially can open new opportunities for achieving efficient PEC water oxidation performance.展开更多
Fabrication of heterostructure composed of one-dimensional(1D)and 2D semiconductors has inspired extensive interest in promoting photogenerated charge separation as well as performances of solar fuel production,but it...Fabrication of heterostructure composed of one-dimensional(1D)and 2D semiconductors has inspired extensive interest in promoting photogenerated charge separation as well as performances of solar fuel production,but it is still challenging for(oxy)nitride photocatalysts due to their uncontrollable ammonia thermal preparative process.In this work,we report a synthesis on heterostructure of Ta_(3)N_(5)nanorods and CaTaO_(2)N(CTON)nanosheets(denoted as Ta_(3)N_(5)/CTON)by directly nitriding a 2D Dion-Jacobson(DJ)type of perovskite KCa_(2)Ta_(3)O_(10)(KCTO)precursor under the assistance of K_(2)CO_(3)flux.It is demonstrated that the 2D morphology of KCTO can be well inherited to get 2D CTON,and the Ta-rich(nonstoichiometric ratio of Ca:Ta compared to CTON)feature of the KCTO as well as the easy evaporation of K species results in the formation of 1D Ta_(3)N_(5)nanorods.Meanwhile,the formation of intermediate species K_(2)Ca_(2)Ta_(3)O_(9)N owning similar crystal lattice as Ta_(3)N_(5)was detected and deduced to be responsible for the generation of Ta_(3)N_(5)nanorods and observation of intimate interface between CTON and Ta_(3)N_(5).Benefitting from the formation of special 1D/2D type-II heterostructure,obviously promoted charge separation as well as photocatalytic water splitting performance can be obtained.Extended discussion demonstrates the generality of the hard-template preparative strategy developed here.To our knowledge,this should be the first fabrication of 1D/2D heterostructure for the(oxy)nitride semiconductors,and the developed hard-template strategy may provide an alternative way of fabricating heterostructures of other semiconductors prepared at high temperature.展开更多
基金support from the Ministry of Science and Technology of China (No. 2016YFA0202803 and 2018YFA0704503)the National Natural Science Foundation of China (21991152,21991150, 21802096, 21832004, 21902179 and 22072093)+2 种基金the Shanghai-XFEL Beamline Project (SBP) (no. 31011505505885920161A2101001)supported by ME2 project under contract No.11227902 from National Natural Science Foundation of Chinasupport of Shanghai Sailing Program (No. 19YF1455600)。
文摘Photoelectrochemical(PEC)water-splitting using solar energy holds great promise for the renewable energy future,and a key challenge in the development of industry viable PEC devices is the unavailability of high-efficient photoanodes.Herein,we designed a TiO_(2) model photocatalyst with nano-groove pattern and different surface orientation using low-energy Ar+irradiation and photoetching of TiO_(2),and significantly improved the intrinsic activity for PEC water oxidation.High-resolution transmission electron microscopy directly manifests that the grooves consist of highly stepped surface with<110>steps and well-crystallized.Transient absorption spectroscopy reveals the groove surface that allows for increased recovery lifetime,which ensures promoted electron-hole separation efficiency.Surface photovoltage directly shows the carrier separation and transportation behaviors,verified by selective photodeposition,demonstrating the groove surface on TiO_(2) contributes to electron-hole separation.This work proposes an efficient and scalable photoanode strategy,which potentially can open new opportunities for achieving efficient PEC water oxidation performance.
基金the Fundamental Research Center of Artificial Photosynthesis(FRe CAP),financially supported by the National Natural Science Foundation of China(NSFC)(22088102)supported by the National Natural Science Foundation of China(21633009,21633010,21925206)+4 种基金the Cooperation Fund of Dalian National Laboratory for Clean Energy(DNL 201913)the International Partnership Program of Chinese Academy of Sciences(121421KYSB20190025)the Dalian Institute of Chemical Physics foundation of innovative research(DICP I201927)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB17000000)the support from Liaoning Revitalization Talents Program(XLYC1807241)。
文摘Fabrication of heterostructure composed of one-dimensional(1D)and 2D semiconductors has inspired extensive interest in promoting photogenerated charge separation as well as performances of solar fuel production,but it is still challenging for(oxy)nitride photocatalysts due to their uncontrollable ammonia thermal preparative process.In this work,we report a synthesis on heterostructure of Ta_(3)N_(5)nanorods and CaTaO_(2)N(CTON)nanosheets(denoted as Ta_(3)N_(5)/CTON)by directly nitriding a 2D Dion-Jacobson(DJ)type of perovskite KCa_(2)Ta_(3)O_(10)(KCTO)precursor under the assistance of K_(2)CO_(3)flux.It is demonstrated that the 2D morphology of KCTO can be well inherited to get 2D CTON,and the Ta-rich(nonstoichiometric ratio of Ca:Ta compared to CTON)feature of the KCTO as well as the easy evaporation of K species results in the formation of 1D Ta_(3)N_(5)nanorods.Meanwhile,the formation of intermediate species K_(2)Ca_(2)Ta_(3)O_(9)N owning similar crystal lattice as Ta_(3)N_(5)was detected and deduced to be responsible for the generation of Ta_(3)N_(5)nanorods and observation of intimate interface between CTON and Ta_(3)N_(5).Benefitting from the formation of special 1D/2D type-II heterostructure,obviously promoted charge separation as well as photocatalytic water splitting performance can be obtained.Extended discussion demonstrates the generality of the hard-template preparative strategy developed here.To our knowledge,this should be the first fabrication of 1D/2D heterostructure for the(oxy)nitride semiconductors,and the developed hard-template strategy may provide an alternative way of fabricating heterostructures of other semiconductors prepared at high temperature.
