Oxygen vacancy enhanced photocatalytic activity of Cu2O/TiO2 heterojunction
Hong Qian,
Binxia Yuan,
Yuhao Liu,
Rui Zhu,
Weiling Luan,
Chengxi Zhang
Affiliations
Hong Qian
College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 201306, P.R. China
Binxia Yuan
College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 201306, P.R. China; School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China; Corresponding author
Yuhao Liu
College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 201306, P.R. China
Rui Zhu
College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 201306, P.R. China
Weiling Luan
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China; Corresponding author
Chengxi Zhang
Department of Optoelectronic Information Science and Engineering, School of Science, Jiangsu University of Science and Technology, Zhenjiang 212100, China
Summary: In this study, a method was developed to create oxygen vacancies in Cu2O/TiO2 heterojunctions. By varying the amounts of ethylenediaminetetraacetic acid (EDTA), sodium citrate, and copper acetate, Cu2O/TiO2 with different Cu ratios were synthesized. Tests on CO2 photocatalytic reduction revealed that Cu2O/TiO2’s performance is influenced by Cu content. The ideal Cu mass fraction in Cu2O/TiO2, determined by inductively coupled plasma (ICP), is between 0.075% and 0.55%, with the highest CO yield being 10.22 μmol g−1 h−1, significantly surpassing pure TiO2. High-resolution transmission electron microscopy and electron paramagnetic resonance studies showed optimal oxygen vacancy in the most effective heterojunction. Density functional theory (DFT) calculations indicated a 0.088 eV lower energy barrier for ∗CO2 to ∗COOH conversion in Cu2O/TiO2 with oxygen vacancy compared to TiO2, suggesting that oxygen vacancies enhance photocatalytic activity.
