Comparing Graphene-TiO2 Nanowire and Graphene-TiO2 Nanoparticle Composite Photocatalysts

We demonstrate that uniform dispersion of TiO2 on graphene is critical for the photocatalytic effect of the composite. The hydrothermal method was employed to synthesize TiO2 nanowires (NW) and then fabricate graphene-TiO2 nanowire nanocomposite (GNW). Graphene oxide (GO) reduction to graphene and hybridization between TiO2 NWs and graphene by forming chemical bonding was achieved in a one-step hydrothermal process. Graphene-TiO2 nanoparticle (NP) nanocomposite (GNP) was also synthesized Photocatalytic performance and related properties of NP, NW, GNP, and GNW were comparatively studied It was found that by incorporation of graphene, GNP and GNW have higher performance than their counterparts. More importantly, it was found that NWs, in comparison with NPs, have more uniform dispersion on graphene with less agglomeration, resulting in more direct contact between TiO2 and graphene, and hence further improved electron-hole pairs (EHPs) separation and transportation. The adsorbability of GNW is also found to be higher than GNP. The result reveals that the relative photocatalytic activity of GNW is much higher than GNP and pure NWs or NPs.