Graphene/TiO2 hydrogel: A potential catalyst to hydrogen evolution reaction

Abstract

In this study, graphene was synthesized from graphite. Graphite was oxidized via modified Hummer's method and sonicated to form graphene oxide (GO). Infrared spectroscopy revealed the successful oxidation of graphite by the emergence of oxygen functionalities. The spectrum of GO showed peaks at 3270, 1629, 1227 and 1096 cm?1, indicating O-H, C=O, C-OH and C-O-C functional groups, respectively. Graphene hydrogels were prepared by the addition of L-ascorbic acid toGOsuspensions and subsequent heating at 90?C. Composite hydrogels of graphene and titanium (IV) oxide (TiO2) were synthesized with various TiO2 to GO mass ratios. Composites were applied to photocatalytic hydrogen evolution reaction (HER) and the hydrogen gas produced was analysed by gas chromatography with thermal conductivity detector. Highest HER yield was 66.00% H2.