Polymer-supported graphene–TiO₂ doped with nonmetallic elements with enhanced photocatalytic reaction under visible light

Exploiting photocatalysts with environmental friendliness, noble-metal-free and high efficiency is a great challenge for photocatalytic hydrogen evolution under visible light. In this work, we had successfully loaded anatase titanium dioxide with a special graphene structure [the reduced graphene oxide loaded on amine-functionalized poly (styrene/glycidyl methacrylate) (rGO/PSGM) microspheres. This special structure could greatly improve the catalytic performance of TiO₂ in the visible light. The nonmetallic elements (C, N, F, P and S) were doped with TiO₂ to further improve the performance of the composite photocatalysts in the visible-light region. After the first-principles density functional theory calculation, the calculated results of the density of states and dielectric function showed that the doped N element has the highest optical absorption capacity. We had proved this through experimental synthesis. Under the full-wavelength illumination, the degradation rate was 20 times higher than that of physically mixed sample; under the visible light, the k value of the degradation rate was 0.0046 min⁻¹ while physically mixed sample had almost no reaction within 5 h. Our study provides a promising approach to achieving efficient photocatalytic reaction under visible light based on TiO₂ and graphene without precious metals.