Design and preparation of CdS/H-3D-TiO2/Pt-wire photocatalysis system with enhanced visible-light driven H-2 evolution

摘要

In recent years, tremendous efforts have been devoted to develop new photocatalyst with wide spectrum response for H-2 generation from water or aqueous solution. In this work, CdS nanoparticles (NPs) have been immobilized on hydrogenated three-dimensional (3D) branched TiO2 nanorod arrays, resulting in a highly efficient photocatalyst, i.e, CdS/H-3D-TiO2. In addition, electrochemical reduction of H+ ion is identified as a limiting step in the photocatalytic generation of H-2 at this catalyst, while here a Pt wired photocatalysis system (CdS/H-3D-TiO2/Pt-wire) is designed to overcome this barrier. Without the application of potential bias, visible light photocatalytic hydrogen production rate of CdS/H-3D-TiO2/Pt-wire is 18.42 mu mol cm(-2) h(-1), which is 11.2 times that of CdS/H-3D-TiO2 without Pt (1.64 umol cm-2 h-1). The Pt wire acts as an electron super highway between the FTO substrate and H+ ions to evacuate the generated electrons to H+ ions and catalyze the reduction reaction and consequently generate H-2 gas. This work successfully offers a novel direction for dramatic improvement in H-2 generation efficiency in photocatalysis field. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.