Visible-light driven Gd2Ti2O7/GdCrO3 composite for hydrogen evolution

Abstract

A series of Gd₂Ti₂O₇/GdCrO₃ composites are prepared by solid state combustion method using Gd(NO₃)₃, TiO₂, Cr₂O₃ as metal source and urea as a fuel. The composites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible diffuse reflectance spectra (DRUV–vis), Brunauer–Emmett–Teller (BET) surface area measurements, photoluminescence spectra (PL), X-ray photoelectron spectroscopic (XPS) studies, photocurrent measurements etc. The photocatalytic activity of the composites is examined towards hydrogen production without using any co-catalyst under visible light illumination. The rate of formation of hydrogen is measured by the photocatalytic activity measurement device and gas chromatography (GC). The highest efficiency is observed over the composite GTC (Cr:Gd:Ti = 1 : 1 : 1). On the basis of photocurrent measurements and PL, a mechanism for the enhanced photocatalytic activity has been discussed.