The effective adsorption of oxygen(O_(2))molecules over photocatalysts is a critical step in promoting the performance of photocatalytic H_(2) O_(2) production.However,g-C_(3)N_(4) usually features a Yeager-type(side-...The effective adsorption of oxygen(O_(2))molecules over photocatalysts is a critical step in promoting the performance of photocatalytic H_(2) O_(2) production.However,g-C_(3)N_(4) usually features a Yeager-type(side-on)adsorption configuration of O_(2) molecules,which causes the breaking of O-O bonds and severely hinders the H_(2) O_(2) production activity.Herein,we synthesized an oxygen-vacancy-rich TiO_(2-x)/g-(3)N_(4) step-scheme(S-scheme)heterojunction to regulate the oxygen adsorption configuration and improve the 2e-ORR se-lectivity of H_(2) O_(2) production.In-situ X-ray photoelectron spectroscopy(in-situ XPS)and density functional theory(DFT)calculations reveal that the S-scheme heterojunction is formed between TiO_(2-x) and g-(3)N_(4).The difference between their Fermi levels leads to the electron flow from g-(3)N_(4) to TiO_(2-x),which in-creases the electron-deficient sites in g-(3)N_(4).As a result,the cleavage of O-O bonds on the surface of g-(3)N_(4) is avoided and the oxygen adsorption configuration is tuned from Yeager-type to Pauling-type(end-on).Consequently,the photocatalytic H_(2) O_(2) production rate is dramatically improved to 1780.3μmol h-1,which is about 5 times higher than that of pristine g-(3)N_(4).This work paves a new way to tailor the oxygen adsorption configuration by rationally designing S-scheme heterojunction photocatalysts.展开更多
基金supported by the National Nature Science Foundation of China(Nos.22272110,22178224,and 22002091)the Fundamental Research Funds for Shenzhen Technology Uni-versity(No.20211063010047)+1 种基金the Guangdong Basic and Ap-plied Basic Research Foundation(Nos.2020A1515110873 and 2023A1515110535)the Shenzhen Science and Technology Pro-gram(No.20231127203830001).
文摘The effective adsorption of oxygen(O_(2))molecules over photocatalysts is a critical step in promoting the performance of photocatalytic H_(2) O_(2) production.However,g-C_(3)N_(4) usually features a Yeager-type(side-on)adsorption configuration of O_(2) molecules,which causes the breaking of O-O bonds and severely hinders the H_(2) O_(2) production activity.Herein,we synthesized an oxygen-vacancy-rich TiO_(2-x)/g-(3)N_(4) step-scheme(S-scheme)heterojunction to regulate the oxygen adsorption configuration and improve the 2e-ORR se-lectivity of H_(2) O_(2) production.In-situ X-ray photoelectron spectroscopy(in-situ XPS)and density functional theory(DFT)calculations reveal that the S-scheme heterojunction is formed between TiO_(2-x) and g-(3)N_(4).The difference between their Fermi levels leads to the electron flow from g-(3)N_(4) to TiO_(2-x),which in-creases the electron-deficient sites in g-(3)N_(4).As a result,the cleavage of O-O bonds on the surface of g-(3)N_(4) is avoided and the oxygen adsorption configuration is tuned from Yeager-type to Pauling-type(end-on).Consequently,the photocatalytic H_(2) O_(2) production rate is dramatically improved to 1780.3μmol h-1,which is about 5 times higher than that of pristine g-(3)N_(4).This work paves a new way to tailor the oxygen adsorption configuration by rationally designing S-scheme heterojunction photocatalysts.
