Visible Light Active Carbon Modified (CM)-p-WO3 Thin Film Electrodes for Photosplitting of Water

Abstract

Carbon modified p-type tungsten oxide (CM-p-WO3) photoelectrodes were synthesized by flame oxidation of tungsten metal sheets (Alfa Co. 0.25 mm thick) at several temperatures for different lengths of time. The photocatalytic activity of CM-p-WO3 was evaluated by measuring the rate of water splitting reaction to hydrogen and oxygen, which is proportional to photocurrent density, jp. Carbon modified tungsten oxide photoelectrodes exhibited p-type photoresponse in acidic medium of 0.5 M H2SO4. The highest photocurrent density of 2.08 mA cm-2 was observed under illumination intensity of 80 mW cm-2 from a 150 Watt (Kratos Model LH 150/1) Xenon arc lamp at an optimal thermal oxidation temperature of 900 {degree sign}C for15 min at applied potential of -0.4 V vs Eaoc. These CM-p-WO3 photoelectrodes were found to generate highest photoconversion efficiency of 2.16 % for photosplitting of water.