Photodeposited Construction of Pt-CdS/g-CN-MnO Composite Photocatalyst for Efficient Visible-Light-Driven Overall Water Splitting.

For converting the renewable solar energy to hydrogen (H) energy by photocatalytic (PC) overall water splitting (OWS), visible-light-driven photocatalysts are especially desired. Herein, a model CdS/g-CN photocatalyst with a type II heterojunction is first demonstrated via a facile coupling of g-CN nanosheets and CdS nanorods. After being combined with photodeposited 3 wt % Pt and 4 wt % MnO dual cocatalysts simultaneously, the optimal visible-light-driven (λ > 400 nm) composite photocatalyst of Pt-CdS/g-CN-MnO gives a H generation rate of 9.244 μmol h (924.4 μmol h g) and a O evolution rate of 4.6 μmol h (460 μmol h g) in pure water, which is over 420 times higher than that of pure CdS nanorods loaded with 0.5 wt % Pt. The apparent quantum efficiency (AQE) reaches about 3.389% (at 400 nm) and 1.745% (at 420 nm), respectively. The combination of a type II heterojunction and simultaneous photodeposition of the dual cocatalysts results in a dramatically improved PC efficiency and a long-term stability of the CdS/g-CN visible-light-driven photocatalyst for OWS.