Enhanced photo-electrochemical performances of graphene-based composite functionalized by Zn2+ tetraphenylporphyrin

•With the aid of π–π stacking interaction, the graphene was successfully functionalized by zinc tetraphenylporphyrin.•In obtained G/ZnTPP composite, the ZnTPP and graphene can substitute for porphyrin-like ring structure and electron transport chain, respectively.•Combined with graphene, the G/ZnTPP composite shows a high photo-electrochemical performance. Inspired by the role of electron transport chain in chlorophyll, graphene (G) complexation with zinc 5, 10, 15, 20-tetraphenylporphyrin (ZnTPP) is expected to have excellent photo-electrochemical performances. Here, we design a facile strategy to synthesize the functionalized graphene/zinc tetraphenylporphyrin (G/ZnTPP) composite. In which, all characterizations indicate synergistic effect does exist between graphene sheets and ZnTPP. The synergistic effect enables such composite to possess improved photo-electrochemical behaviors that are key features for photoelectric conversion device. On the basis of this, attempts to modify the absorption range, improve specific capacitance and lower resistance to acquire effective photo-current responses have been successfully demonstrated in this research.