Improved Synthesis of Reduced Graphene Oxide-Titanium Dioxide Composite with Highly Exposed {001} Facets and Its Photoelectrochemical Response

摘要

Crystal facet engineering has attracted worldwide attention, particularly in facet manipulation of titanium dioxide (TiO_2) surface properties. An improved synthesis by solvothermal route has been employed for the formation of TiO_2 with highly exposed {001} facets decorated on reduced graphene oxide (RGO) sheets. The RGO-TiO_2 composite could be produced with high yield by following a stringently methodical yet simple approach. Field emission scanning electron microscope and high resolution transmission electron microscope imaging reveal that the structure consists of TiO_2 nanoparticles covered with TiO_2 nanosheets of exposed {001} facets on a RGO sheet. The photocurrent response of the RGO-TiO_2 composite was discovered to outperform that of pure TiO_2, as a ～10-fold increase in photocurrent density was observed for the RGO-TiO_2 electrodes. This may be attributed to rapid electron transport and the delayed recombination of electron-hole pairs due to improved ionic interaction between titanium and carbon.