Photo-Redeposition Synthesis of Bimetal Pt–Cu Co-catalysts for TiO<sub>2</sub> Photocatalytic Solar-Fuel Production
Jing Liu, Meng Liu, Xianglong Yang, Hao Chen, Shengzhong Liu, Junqing Yan
Abstract
Photocatalytic water splitting for the production of H2 and the reduction of CO2 into carbon compounds via solar energy exhibits possible widespread applications in the energy sector because of their application as so-called solar fuels. However, so far, the efficiency of these processes is low and in need of further improvement. Herein, we report a strategy for boosting the solar fuel generation rate of TiO2 by loading cocatalysts, specifically bimetallic Cu–Pt and CuO, via two-step photodeposition processes. Intriguingly, we can for the first time observe that the Cu2O nanoparticles present on the surface of TiO2 are partially redissolved into the solution because of the weak acidity induced by the Pt precursor. The sample of Cu–Pt/TiO2–CuO shows a photocatalytic H2 generation rate of 173.7 μmol/g·h under simulated sunlight conditions. For the photocatalytic CO2 reduction by water, the sample of Cu–Pt/TiO2–CuO shows the release of H2, O2, CO, CH4, and CH3OH, whereby CO is the main reaction product. Typically, the yields of O2 and CO are 4.2 and 6.2 and 2.1 and 3.2 μmol/h·g under LED-405 and LED-425, respectively; the CO2-to-CO conversion ratios with respect to separated carriers are 73.8 and 76.19%.