Design of a Pt/TiO2–xNx/SrTiO3 triplejunction for effective photocatalytic H2 production under solar light irradiation

Abstract

This study prepared a novel photocatalyst for effective H2 production under solar light irradiation. A Pt/TiO2–xNx/SrTiO3 triplejunction was designed by growing N-doped TiO2 on SrTiO3 and then loading Pt onto the photocatalyst. The as-prepared photocatalyst was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission-scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results proved the successful fabrication of the triplejunction. The photocatalytic H2 production rate indicated that the performance of the triplejunction was effectively enhanced. This enhancement can be ascribed to the photogenerated charges transfer from SrTiO3 to the N-doped TiO2 as well as the photogenerated charges separation caused by the Pt metal coating on the outer layer, which formed a Schottky barrier between the metal and the semiconductor. The valence and conduction bands in each junction were arranged according to decreasing flat band potential, thereby causing the migration of photogenerated charges from the interior to the surface. Thus, the designed Pt/TiO2–xNx/SrTiO3 triplejunction is an effective photocatalyst for H2 production.