Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, Texas 79409-3102, United States.
ACS Appl Mater Interfaces. 2012 Aug;4(8):3944-50. doi: 10.1021/am300772t. Epub 2012 Jul 20.
We demonstrate that uniform dispersion of TiO(2) on graphene is critical for the photocatalytic effect of the composite. The hydrothermal method was employed to synthesize TiO(2) nanowires (NW) and then fabricate graphene-TiO(2) nanowire nanocomposite (GNW). Graphene oxide (GO) reduction to graphene and hybridization between TiO(2) NWs and graphene by forming chemical bonding was achieved in a one-step hydrothermal process. Graphene-TiO(2) 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 TiO(2) 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.
我们证明了 TiO(2) 在石墨烯上的均匀分散对于复合材料的光催化效果至关重要。采用水热法合成了 TiO(2) 纳米线（NW），然后制备了石墨烯-TiO(2) 纳米线纳米复合材料（GNW）。通过一步水热过程实现了氧化石墨烯（GO）还原为石墨烯以及 TiO(2) NWs 和石墨烯之间通过形成化学键的杂交。还合成了石墨烯-TiO(2) 纳米颗粒（NP）纳米复合材料（GNP）。比较研究了 NP、NW、GNP 和 GNW 的光催化性能和相关性质。结果发现，通过掺入石墨烯，GNP 和 GNW 的性能比它们的对应物更高。更重要的是，发现与 NPs 相比，NWs 在石墨烯上具有更均匀的分散且团聚较少，从而使 TiO(2) 和石墨烯之间有更多的直接接触，进而进一步提高了电子-空穴对（EHPs）的分离和传输。还发现 GNW 的吸附能力也高于 GNP。结果表明，GNW 的相对光催化活性远高于 GNP 和纯 NWs 或 NPs。
