Production of Ch4 and Co on Cuxo and Nixoy Coatings Through Co2 Photoreduction Under Visible Light

CO 2 capture and photocatalytic reduction to hydrocarbons is an interesting yet challenging area that requires photocatalysts with the capability to capture and photoconvert CO 2 simultaneously. Furthermore, photocatalysts with high efficiency and product selectivity are essential for commercialization. Thus, a facile one-step microwave-hydrothermal approach was demonstrated herein to fabricate Cu x O (x=1, 2) and Ni x O y (x=1, 2 and y =1, 3) coatings on glass fiber for CO 2 photoreduction under irradiation of 300-600 nm using a continuous flow and a batch system separately. CuO/Cu 2 O photocatalysts exhibited a selective production of CH 4 (95 µmol g -1 h -1 ) and CH 3 OH (177 µmol g -1 h -1 ) from CO 2 photoreduction in the gas and liquid phases, respectively. The superior performance was attributed to the unique rod-shape morphology, the presence of oxygen vacancies and efficient charge transfer in the CuO/Cu 2 O heterostructure with high affinity towards CO 2 , resulting the formation of mono- and bidentate carbonate species during the CO 2 photoreduction reaction. Ni x O y coating with 2D cubic shape produced only CO (103 µmol g -1 h -1 ), associating with the low CO 2 affinity and less efficient charge separation compared to CuO/Cu 2 O heterostructure