Photocatalytic hydrogen generation from water using a hybrid of graphene nanoplatelets and self doped TiO2-Pd

Nanohybrids of self doped (Ti doped or reduced TiO -TiOR) TiO-graphene nanoplatelets (TiO R-G) of different compositions are synthesized by a facile soft chemical method. A decrease of bandgap and improved visible light absorption is exhibited by TiOR-G. Based on current-voltage (I-V) measurements, it is concluded that the hybrid material possesses improved electron transport properties compared to TiOR and pure TiO. A detailed characterization of the composites indicated that TiOR exists as a dispersed phase on graphene nanoplatelets (graphene). Among different compositions of the composites, the catalyst containing 3 weight% of graphene (TiOR-3G) shows enhanced photocatalytic activity for hydrogen generation from water compared to both TiO and TiOR. When Pd is used as co-catalyst 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 Ti 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 co-catalyst. This work highlights the role of TiO based hybrid materials as efficient photocatalysts for solar energy utilization. This journal i