▎ 摘　　要

Nanohybrids of self doped (Ti3+ doped or reduced TiO2-TiO2R) TiO2-graphene nanoplatelets (TiO2R-G) of different compositions are synthesized by a facile soft chemical method. A decrease of bandgap and improved visible light absorption is exhibited by TiO2R-G. Based on current-voltage (I-V) measurements, it is concluded that the hybrid material possesses improved electron transport properties compared to TiO2R and pure TiO2. A detailed characterization of the composites indicated that TiO2R exists as a dispersed phase on graphene nanoplatelets (graphene). Among different compositions of the composites, the catalyst containing 3 weight% of graphene (TiO2R-3G) shows enhanced photocatalytic activity for hydrogen generation from water compared to both TiO2 and TiO2R. When Pd is used as cocatalyst in this composite, a large increase in the activity is observed. The increased efficiency of the nanocomposite is attributed to factors like: (i) improved visible light absorption promoted by G and Ti3+ dopant (ii) increased lifetime of the charge carriers assisted by the enhanced electron transporting properties of G (iii) increased number of active sites for hydrogen evolution provided by the Pd cocatalyst. This work highlights the role of TiO2 based hybrid materials as efficient photocatalysts for solar energy utilization.