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For converting the renewable solar energy to hydrogen (H2) energy by photocatalytic (PC) overall water splitting (OWS), visible-light-driven photocatalysts are especially desired. Herein, a model CdS/g-C3N4photocatalyst with a type II heterojunction is first demonstrated via a facile coupling of g-C3N4nanosheets and CdS nanorods. After being combined with in situphotodeposited 3 wt % Pt and 4 wt % MnOxdual cocatalysts simultaneously, the optimal visible-light-driven (λ > 400 nm) composite photocatalyst of Pt–CdS/g-C3N4–MnOxgives a H2generation rate of 9.244 μmol h–1(924.4 μmol h–1g–1) and a O2evolution rate of 4.6 μmol h–1(460 μmol h–1g–1) 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 in situphotodeposition of the dual cocatalysts results in a dramatically improved PC efficiency and a long-term stability of the CdS/g-C3N4visible-light-driven photocatalyst for OWS.

As one of the most promising Pt alternatives for cost-effective hydrogen production, molybdenum disulfide (MoS2), although has been studied extensively to improve its electrocatalytic activity, suffers from scarce active sites, low conductivity, and lack of interaction with substrates. To this end, we anchor ultradispersed and single-layered MoS2nanoflakes on graphene sheets via a hybrid intermediate (MoOx–cysteine–graphene oxide), which not only confines the subsequent growth of MoS2on the graphene surface but also ensures the intimate interaction between Mo species and graphene at the initial stage. Mo–O–C bond and a possible residual MoO3–xlayer are proposed to comprise the interface bridging the two inherent incompatible phases, MoS2and graphene. This strongly coupled structure together with the highly exposed MoS2morphology accelerates the electron injection from graphene to the active sites of MoS2, and thus the hydrogen evolution reaction (HER) can achieve an overpotential of ∼275 mV at ∼−740 mA cm–2, and a Pt-like Tafel slope of ∼35 mV dec–1. Our results shed light on the indispensable role of interfacial interaction within semiconducting material–nanocarbon composites and provide a new insight into the actual activity of MoS2toward the HER.