Selective deposition of plasmonic copper on few layers graphene with specific defects for efficiently synchronous photocatalytic hydrogen production

Abstract： Graphene from chitosan (CG) with wrinkle, few layers and specific defects was prepared via a simple method of low carbonization temperature and high KOH activation temperature. At the activation temperature of 1100 °C, the obtained CG-1100 has the specific surface of 1212 m 2 ·g −1 and the total volume of 1.02 cm 3 ·g −1 at the optimized activation temperature. The results show that the CG-1100 is similar to another two graphenes: graphene nanoparticles (GNP) and multilayer graphene powders (MGP), which contain less defects. The Cu/CG-1100 composite photocatalyst was prepared from CG-1100 and Cu(Ac) 2 solution with surface plasmon resonance (SPR) effect by in-situ synthesis method under illumination. When the binary composite contains 10 wt% of Cu NPs, the hydrogen evolution rate of Cu/CG-1100 photocatalyst reached 3.94 mmol·g −1 ·h −1 , which is 3.2 times as high as that of pure Cu NPs. Interestingly, the defect sites of the graphene can influence the photocatalytic hydrogen production rate which was observed by depositing Cu NPs on GNP and MGP. The results showed that more defects on the graphene presented higher photocatalytic hydrogen evolution rate.