Optically Active Oxygen Defects in Titanium Dioxide Doped with Inorganic Acid Ions
Bin Xu,
Xuehui Duan,
Tao Zhou,
Jinliang Hao,
Haotian Qin,
Youcai Zhao,
Wei Ye,
Jianglin Cao
Affiliations
Bin Xu
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Xuehui Duan
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Tao Zhou
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Jinliang Hao
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Haotian Qin
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Youcai Zhao
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Wei Ye
School of Mechanical Engineering, Tongji University, Shanghai 201804, China
Jianglin Cao
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Doping inorganic acid ions represents a promising pathway to improving the photocatalytic activity of TiO2, and oxygen vacancy has been regarded as the determinant factor for photocatalytic activity. A series of samples doped with Cl−, NO3−, and SO42− was prepared via a simple sol–gel method. Two different oxygen vacancies in the crystal layer of NO3−/TiO2 and Cl−/TiO2 were found, and those are [Ti3+]-V0-[Ti3+] and [Ti3+]-Cl, respectively. The photocurrent of NO3−/TiO2 with [Ti3+]-V0-[Ti3+] is significantly greater than that of Cl−/TiO2 with [Ti3+]-Cl. The least oxygen vacancy is in the gel layer of SO42−/TiO2, and the negligible photocurrent is due to difficulty in forming a stable sol. Furthermore, the process conditions for the application of TiO2 were investigated in this work. The optimal process parameters are to adjust the solution to pH = 3 during sol–gel preparation, to adopt 550 °C as the calcination temperature, and to use an alkaline electrolyte, while the rest of the preparation conditions remain unchanged. This work reveals a new avenue for designing efficient photocatalysts for air pollutant degradation.
