Photocatalytic aerobic oxidation by using oxygen molecules(O_(2))as green and low-cost oxidants is of great attraction,where the introduction of irradiation has been proved as an efficient strategy to lower reaction t...Photocatalytic aerobic oxidation by using oxygen molecules(O_(2))as green and low-cost oxidants is of great attraction,where the introduction of irradiation has been proved as an efficient strategy to lower reaction temperature as well as promote catalytic performance.Moreover,the oxygen vacancies(OVs)of catalyst are highly active sites to adsorb and activate O_(2)during photocatalytic aerobic oxidation.However,OVs are easily blocked by oxygen atoms from active oxygen species during the catalytic process,leading to the deactivation of catalysis.Herein,a promising catalyst toward photocatalytic aerobic oxidation was successfully developed by recovering the OVs through doping Au atoms into Ti_(3)C_(2)T_(x)MXene(Au/Ti_(3)C_(2)T_(x)).Impressively,Au/Ti_(3)C_(2)T_(x)exhibited remarkable activity under full-spectrum irradiation towards photooxidation of methyl phenyl sulfide(MPS)and methylene blue(MB),attaining a conversion of>90%at room temperature.Moreover,Au/Ti_(3)C_(2)T_(x)also manifested remarkable stability by maintaining>95%initial activity after 10 successive reaction rounds.Further mechanistic studies indicated that the OVs of Au/Ti_(3)C_(2)T_(x)served as the active centers to efficiently adsorb and activate O_(2).More importantly,the doped Au atoms of Au/Ti_(3)C_(2)T_(x)were conducive to the recovery of OVs during photocatalytic process from the results of theoretical and experimental aspects.The recovered OVs of Au/Ti_(3)C_(2)T_(x)continuously and efficiently activated O_(2),directly contributing to the remarkable catalytic activity and stability.展开更多
Here,we reply to comments by Valentic et al.on our paper published in Electrochimica Acta（2014,130：279）.They commented that Au nanoparticles played the dominant role on the whole cell＇s performances in our improve...Here,we reply to comments by Valentic et al.on our paper published in Electrochimica Acta（2014,130：279）.They commented that Au nanoparticles played the dominant role on the whole cell＇s performances in our improved graphene/Si solar cell.We argued that our devices are Au-doped graphene/n-Si Schottky barrier devices,not Au nanoparticles（film）/n-Si Schottky barrier devices.During the doping process,most of the Au nanopatricles covered the surfaces of the graphene.Schottky barriers between doped graphene and n-Si dominate the total cells properties.Through doping,by adjusting and tailoring the Fermi level of the graphene,the Fermi level of n-Si can be shifted down in the graphene/Si Schottky barrier cell.They also argued that the instability of our devices were related to variation in series resistance reduced at the beginning due to slightly lowered Fermi level and increased at the end by the serf-compensation by deep in-diffusion of Au nanoparticles.But for our fabricated devices,we know that an oxide layer covered the Si surface,which makes it difficult for the Au ions to diffuse into the Si layer,due to the continuous growth of SiO2 layer on the Si surface which resulted in series resistance decreasing at first and increasing in the end.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.21976147,11875258,and 51801235)Natural Science Foundation of Hunan Province(Nos.2018RS3019 and 2019JJ30033)+1 种基金Sichuan Science and Technology Program(Nos.2020JDJQ0060 and 2020YFG0160)Innovation-Driven Project of Central South University(No.2018CX004),the Start-up Funding of Central South University(No.502045005)。
文摘Photocatalytic aerobic oxidation by using oxygen molecules(O_(2))as green and low-cost oxidants is of great attraction,where the introduction of irradiation has been proved as an efficient strategy to lower reaction temperature as well as promote catalytic performance.Moreover,the oxygen vacancies(OVs)of catalyst are highly active sites to adsorb and activate O_(2)during photocatalytic aerobic oxidation.However,OVs are easily blocked by oxygen atoms from active oxygen species during the catalytic process,leading to the deactivation of catalysis.Herein,a promising catalyst toward photocatalytic aerobic oxidation was successfully developed by recovering the OVs through doping Au atoms into Ti_(3)C_(2)T_(x)MXene(Au/Ti_(3)C_(2)T_(x)).Impressively,Au/Ti_(3)C_(2)T_(x)exhibited remarkable activity under full-spectrum irradiation towards photooxidation of methyl phenyl sulfide(MPS)and methylene blue(MB),attaining a conversion of>90%at room temperature.Moreover,Au/Ti_(3)C_(2)T_(x)also manifested remarkable stability by maintaining>95%initial activity after 10 successive reaction rounds.Further mechanistic studies indicated that the OVs of Au/Ti_(3)C_(2)T_(x)served as the active centers to efficiently adsorb and activate O_(2).More importantly,the doped Au atoms of Au/Ti_(3)C_(2)T_(x)were conducive to the recovery of OVs during photocatalytic process from the results of theoretical and experimental aspects.The recovered OVs of Au/Ti_(3)C_(2)T_(x)continuously and efficiently activated O_(2),directly contributing to the remarkable catalytic activity and stability.
文摘Here,we reply to comments by Valentic et al.on our paper published in Electrochimica Acta（2014,130：279）.They commented that Au nanoparticles played the dominant role on the whole cell＇s performances in our improved graphene/Si solar cell.We argued that our devices are Au-doped graphene/n-Si Schottky barrier devices,not Au nanoparticles（film）/n-Si Schottky barrier devices.During the doping process,most of the Au nanopatricles covered the surfaces of the graphene.Schottky barriers between doped graphene and n-Si dominate the total cells properties.Through doping,by adjusting and tailoring the Fermi level of the graphene,the Fermi level of n-Si can be shifted down in the graphene/Si Schottky barrier cell.They also argued that the instability of our devices were related to variation in series resistance reduced at the beginning due to slightly lowered Fermi level and increased at the end by the serf-compensation by deep in-diffusion of Au nanoparticles.But for our fabricated devices,we know that an oxide layer covered the Si surface,which makes it difficult for the Au ions to diffuse into the Si layer,due to the continuous growth of SiO2 layer on the Si surface which resulted in series resistance decreasing at first and increasing in the end.
