Design and preparation of CdS/H-3D-TiO2/Pt-wire photocatalysis system with enhanced visible-light driven H2 evolution

Abstract

In recent years, tremendous efforts have been devoted to develop new photocatalyst with wide spectrum response for H2 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 H2 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 μmol cm−2 h−1, which is 11.2 times that of CdS/H-3D-TiO2 without Pt (1.64 μmol 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 H2 gas. This work successfully offers a novel direction for dramatic improvement in H2 generation efficiency in photocatalysis field.