Assembling graphitic-carbon-nitride with cobalt-oxide-phosphate to construct an efficient hybrid photocatalyst for water splitting application
Tran, Phong D.
Pramana, Stevin S.
Chiam, Sing Yang
Wong, Lydia Helena
Date of Issue2013
School of Materials Science and Engineering
A scalable method to load a cobalt-oxide-phosphate (CoPi) water oxidation electrocatalyst onto the surface of a mesoporous graphitic-carbon-nitride (mpg-CNx) semiconductor is reported. This procedure resulted in significant enhancement of photocatalytic activity of the mpg-CNx in water oxidation. The optimal loading gave an oxygen evolution rate of up to approximately 1 mmol O2 gcat−1 h−1 under 100 mW cm−2 visible light illumination in a pH 7 phosphate buffer containing Ag+ or Na2S2O8 as an electron scavenger which was 400 times faster compared with that of the untreated mpg-CNx catalyst. Under visible light illumination and by employing a hole scavenger e.g. methanol, CoPi was converted into a H2-CoCat HER electrocatalyst which significantly promoted the H2 generation photocatalytic activities of mpg-CNx. Without any electron/hole scavengers, the mpg-CNx–CoPi–H2-CoCat composite was able to catalyse the overall water splitting process.
Catalysis science & technology