Photocatalysis exhibits promise in the reduction of nitrates into harmless dinitrogen.Herein,the synthesis of N-doped TiO_(2)/Ti_(3)C_(2)at a low calcination temperature using NH_(4)Cl and Ti_(3)C_(2)was reported for ...Photocatalysis exhibits promise in the reduction of nitrates into harmless dinitrogen.Herein,the synthesis of N-doped TiO_(2)/Ti_(3)C_(2)at a low calcination temperature using NH_(4)Cl and Ti_(3)C_(2)was reported for the first time.Cationic NH_(4+)was intercalated into the interlayers of Ti_(3)C_(2)and NH_(4)Cl was self-assembled on the surface of Ti_(3)C_(2).N-doped TiO_(2)/Ti_(3)C_(2)was in situ synthesized by one-step calcining the Ti_(3)C_(2)MXene and NH_(4)Cl mixture.The as-prepared composite exhibited excellent activity in the photocatalytic reduction of nitrate.As characterized,the N-dopant added an impurity energy level within the band gap of TiO_(2),which was favourable for improving the light absorption ability.Meanwhile,the metallic nature of Ti_(3)C_(2)with a layered structure accelerated the charge transfer between N-TiO_(2)and Ti_(3)C_(2),and further facilitated the separation of photogenerated charge carriers.Moreover,the addition of formic acid in the solution not only acted as a hole scavenger to produce the reducing agent·CO_(2)^(-),but also provided extra reactive electrons by generating the charge-transfer complex between N-TiO_(2)and formic acid,which greatly promoted the photocatalytic reduction of nitrate.Notably,NO_(3-) with Lewis basic property was easily adsorbed onto the Lewis acid sites on the surface of N-doped TiO_(2)/Ti_(3)C_(2)by the electrostatic force.All the above-mentioned superiorities contributed to the greatly enhanced photocatalytic activity of the N-doped TiO_(2)/Ti_(3)C_(2)composite in the reduction of nitrate.The mechanism has also been proposed based on the testing results.展开更多
基金supported by the Qingdao Municipal Science and Technology Bureau(No.:17-3-3-71-nsh)the Weihai Puyi Marine Environmental Technology Co.,Ltd(No.:0125220)support from Taishan Scholars Foundation of Shandong province(Grant No.:tsqn201909058)。
文摘Photocatalysis exhibits promise in the reduction of nitrates into harmless dinitrogen.Herein,the synthesis of N-doped TiO_(2)/Ti_(3)C_(2)at a low calcination temperature using NH_(4)Cl and Ti_(3)C_(2)was reported for the first time.Cationic NH_(4+)was intercalated into the interlayers of Ti_(3)C_(2)and NH_(4)Cl was self-assembled on the surface of Ti_(3)C_(2).N-doped TiO_(2)/Ti_(3)C_(2)was in situ synthesized by one-step calcining the Ti_(3)C_(2)MXene and NH_(4)Cl mixture.The as-prepared composite exhibited excellent activity in the photocatalytic reduction of nitrate.As characterized,the N-dopant added an impurity energy level within the band gap of TiO_(2),which was favourable for improving the light absorption ability.Meanwhile,the metallic nature of Ti_(3)C_(2)with a layered structure accelerated the charge transfer between N-TiO_(2)and Ti_(3)C_(2),and further facilitated the separation of photogenerated charge carriers.Moreover,the addition of formic acid in the solution not only acted as a hole scavenger to produce the reducing agent·CO_(2)^(-),but also provided extra reactive electrons by generating the charge-transfer complex between N-TiO_(2)and formic acid,which greatly promoted the photocatalytic reduction of nitrate.Notably,NO_(3-) with Lewis basic property was easily adsorbed onto the Lewis acid sites on the surface of N-doped TiO_(2)/Ti_(3)C_(2)by the electrostatic force.All the above-mentioned superiorities contributed to the greatly enhanced photocatalytic activity of the N-doped TiO_(2)/Ti_(3)C_(2)composite in the reduction of nitrate.The mechanism has also been proposed based on the testing results.
