Pompon Dahlia-like Cu2O/rGO Nanostructures for Visible Light Photocatalytic H2 Production and 4-Chlorophenol Degradation

Hierarchical Cu2O nanospheres with a Pompon Dahlia-like morphology were prepared by a one-pot synthesis employing electrostatic self-assembly. Nanocomposite analogues were also prepared in the presence of reduced graphene oxide (rGO). Photophysical properties of the hierarchical Cu2O nanospheres and Cu2O/rGO nanocomposite were determined, and their photocatalytic applications evaluated for photocatalytic 4-chlorophenol (4-CP) degradation and H-2 production. Introduction of trace (<1 wt %) rGO improves the apparent quantum efficiency (AQE) at 475 nm of hierarchical Cu2O for H-2 production from 2.23 % to 3.35 %, giving an increase of evolution rate from 234 mu mol.g(-1).h(-1) to 352 mu mol.g(-1).h(-1) respectively. The AQE for 4-CP degradation also increases from 52 % to 59 %, with the removal efficiency reaching 95 % of 10 ppm 4-CP within 1 h. Superior performance of the hierarchical Cu2O/rGO nanocomposite is attributable to increased visible light absorption, reflected in a greater photocurrent density. Excellent catalyst photostability for >6 h continuous reaction is observed.