A core-satellite structured type II heterojunction photocatalyst with enhanced CO2 reduction under visible light
Yuanyuan Cheng, Yixian Liu, Yunliang Liu, Yaxi Li, Ruqiang Wu, Yongchao Du, Najmeh Askari, Naiyun Liu, Fen Qiao, Chenghua Sun, Zhenhui Kang, Haitao Li
Abstract
Photocatalytic reduction of carbon dioxide into valuable chemicals is a sustainable and promising technology that alleviates the greenhouse effect and energy crisis. In this study, the Mn3O4/FeNbO4 type II heterojunction photocatalyst with a core-satellite structure was synthesized by the facile soft chemical method. The formation of a nano-heterojunction is supposed to effectively improve light capture, charge transfer, and interfacial charge separation in the photochemical reaction. Meanwhile, the heterojunction has a good ability to capture and activate CO2. Our results show that the prepared Mn3O4/FeNbO4 photocatalyst exhibit obvious enhanced catalytic properties in the photocatalytic CO2 reduction reaction, where the CH4 yielding rate is 1.96 and 9.81 times those of FeNbO4 and Mn3O4, respectively. The transient photovoltage test (TPV) shows that the low frequency electrons are crucial to the effective transfer of photogenerated electrons and holes in the Mn3O4/FeNbO4 nano heterojunctions. Analysis of in situ Fourier transform infrared spectroscopy (FTIR) verifies the effective CO2 adsorption on the Mn3O4/FeNbO4 surface and the high selectivity of CH4 products. These properties of the Mn3O4/FeNbO4 photocatalyst infer its broad prospects in the fields of carbon fixation and energy conservation.