Noble Metal-Free RGO/TiO 2 composite nanofiber with enhanced photocatalytic H 2 -production performance

Abstract 1D reduced graphene oxide (RGO)/TiO 2 nanocomposite fibers were fabricated by a facile two-step method. These samples demonstrated high photocatalytic H 2 -production activity from methanol aqueous solution, even without the aid of noble metal. When the ratio of RGO is 0.25 wt%, the highest H 2 -production rate was achieved. It increased by 10 fold than bare TiO 2 , reaching 149 μmol h −1  g −1 with quantum efficiency (QE) of 0.75%. The reasons were as follows. Firstly, the RGO nanosheets acted as electron acceptors. Secondly, some shallow trap states at the surface or interface of TiO 2 were created by the reduction of GO during calcination. Thirdly, the redox potential position of graphene/graphene − was suitable. Fourthly, RGO could efficiently promote the separation of photogenerated electron-hole pairs and significantly enhance the photocatalytic H 2 -production activity. This interpretation was corroborated by transient photocurrent response. The aforementioned marvelous results provided a probable solution to replace noble metals (such as Pt) by graphene as an effective cocatalyst.