A MoS2/6,13-pentacenequinone composite catalyst for visible-light-induced hydrogen evolution in water

6,13-Pentacenequinone (PQ) actively catalyzed the light-driven evolution of hydrogen in water when using MoS2 nanosheets as cocatalyst. The MoS2/PQ composite photocatalyst was prepared via a facile procedure and was fully characterized by X-ray diffraction (XRD), Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy and UV-vis spectroscopy. Layered MoS2 was incorporated on the PQ surface and served as electron traps. This allowed active sites to efficiently promote the separation of photogenerated carriers, thus facilitating the photocatalytic production of hydrogen from water. The effects of the MoS2 loading on the PQ morphology and the pH of the reaction have been evaluated using triethanolamine (TEOA) as a sacrificial reductant. The photocatalytic results showed that the MoS2/PQ composite photocatalyst manifested the highest H-2 production rate of 79.5 mu mol h(-1) g(-1) under visible light irradiation (lambda > 420 nm) at a MoS2 concentration of 0.5 wt%, which exceeds the optimized photocatalytic H-2 evolution activity of Pt-loaded PQ (Pt/PQ) photocatalyst. The heterogeneous catalyst could be readily recovered and recycled at least three times without a significant loss of activity. This study provides new insights into solar-to-energy conversion using composite photocatalysts that are free of noble metals, are environmentally friendly and are responsive to visible light. (C) 2015 Elsevier B.V. All rights reserved.