Comparing Graphene-TiO₂ Nanowire and Graphene-TiO₂ Nanoparticle Composite\nPhotocatalysts

Abstract

We demonstrate that uniform dispersion of TiO₂ on graphene\nis critical for the photocatalytic effect of the composite. The hydrothermal\nmethod was employed to synthesize TiO₂ nanowires (NW) and\nthen fabricate graphene-TiO₂ nanowire nanocomposite (GNW).\nGraphene oxide (GO) reduction to graphene and hybridization between\nTiO₂ NWs and graphene by forming chemical bonding was achieved\nin a one-step hydrothermal process. Graphene-TiO₂ nanoparticle\n(NP) nanocomposite (GNP) was also synthesized. Photocatalytic performance\nand related properties of NP, NW, GNP, and GNW were comparatively\nstudied. It was found that by incorporation of graphene, GNP and GNW\nhave higher performance than their counterparts. More importantly,\nit was found that NWs, in comparison with NPs, have more uniform dispersion\non graphene with less agglomeration, resulting in more direct contact\nbetween TiO₂ and graphene, and hence further improved electron–hole\npairs (EHPs) separation and transportation. The adsorbability of GNW\nis also found to be higher than GNP. The result reveals that the relative\nphotocatalytic activity of GNW is much higher than GNP and pure NWs\nor NPs.