A core-satellite structured type II heterojunction photocatalyst with enhanced CO2 reduction under visible light

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 Mn 3 O 4 /FeNbO 4 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 CO 2 . Our results show that the prepared Mn 3 O 4 /FeNbO 4 photocatalyst exhibit obvious enhanced catalytic properties in the photocatalytic CO 2 reduction reaction, where the CH 4 yielding rate is 1.96 and 9.81 times those of FeNbO 4 and Mn 3 O 4 , 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 Mn 3 O 4 /FeNbO 4 nano heterojunctions. Analysis of in situ Fourier transform infrared spectroscopy (FTIR) verifies the effective CO 2 adsorption on the Mn 3 O 4 /FeNbO 4 surface and the high selectivity of CH 4 products. These properties of the Mn 3 O 4 /FeNbO 4 photocatalyst infer its broad prospects in the fields of carbon fixation and energy conservation.