TiO2 nanosheets decorated with B4C nanoparticles as photocatalysts for solar fuel production under visible light irradiation

Boron carbide (B 4 C) nanoparticles-decorated anatase titanium dioxide (TiO 2 ) nanosheets photocatalysts were synthesized by a hydrothermal method in the presence of hydrofluoric acid and characterized by field emission scanning electron microscope, high-resolution transmission electron microscope, UV–vis diffuse reflectance spectra, photoluminescence spectra, etc. With metallic Pt nanoparticles as a co-catalyst, the as-synthesized B 4 C/TiO 2 composites were evaluated using photocatalytic CO 2 or H 2 O reduction to solar fuels such as methane and hydrogen. Under either simulated sunlight or visible light irradiation, coupling p-type B 4 C with n-type anatase TiO 2 significantly improved the photocatalytic performance. Both photoluminescence and transient photocurrent measurements indicated that the interfacial coupling effect between B 4 C and anatase TiO 2 could significantly promote photo-excited charges separations. On the basis of measurements and literatures, a possible mechanism of excited charges transfer at the B 4 C-anatase TiO 2 heterojunction interface during irradiation was deduced.