Simple synthesis of hierarchically porous Sn/TiO2/graphitic carbon microspheres for CO2 reduction with H2O under simulated solar irradiation

A simple colloidal crystal template method was used to prepare Sn/TiO2/graphite carbon microsphere composites (xSn/TiO2/GCM, x = 2.0, 1.0, 0.2, 0.5) with porous layers. Then, the composites were represented using X-ray diffraction, energy dispersive spectrometry, scanning electron microscopy, transmission electron microscopy, and nitrogen physical adsorption/desorption. Meanwhile, the photocatalytic activities in CO2 reduction were studied under simulation of visible light exposure. It was confirmed that the Sn/TiO2/GCM composites had layered porosity, graphitized carbon matrix, and high metal compound content, and their morphology was greatly affected by the acetone amount. The outputs of CO and CH4 coming into the photocatalytic CO2 reduction reaction of Sn/TiO2/GCM were 619.46 and 14.46 μmol g−1, respectively. Among the two products, the highest production rate observed in 0.5Sn/TiO2/GCM. Because of these factors, the layered porous Sn/TiO2/GCM composites have good photocatalytic performance under simulated visible light irradiation and have unique composition and structure characteristics, which give broad application prospects in electrode materials, catalysts, and adsorbents.