Influence of graphene synthesizing techniques on the photocatalytic performance of Graphene/TiO2 nanocomposites

Journal article, 2013

Model photocatalysts composed of TiO2/graphene nanocomposites are prepared to address the role of graphene quality on their photocatalytic performance. Graphene is synthesized by catalyst-assisted chemical vapor deposition (CVD), catalyst-free CVD and solution processing methods. TiO2 is prepared by reactive magnetron sputtering and subsequent annealing. Fabricated model photocatalysts are with different morphology and physical properties, as revealed by spectrophotometry, atomic force microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy, photoluminescence, and four-probe electrical measurements. All graphene–containing composites are with significantly higher photocatalytic activity compared to bare TiO2 films in the gas phase methanol photooxidation tests. The activity is proportional to the electrical conductivity and surface roughness of the respective carbon structure, which in turn depends on the preparation methods. The mechanisms of enhancement are further assessed by comparison with the performance of reference TiO2/graphitic-carbon and TiO2/Au thin films.