Pompon Dahlia‐like Cu 2 O/rGO Nanostructures for Visible Light Photocatalytic H 2 Production and 4‐Chlorophenol Degradation

Hierarchical Cu 2 O 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 Cu 2 O nanospheres and Cu 2 O/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 Cu 2 O for H 2 production from 2.23 % to 3.35 %, giving an increase of evolution rate from 234 μmol.g −1 .h −1 to 352 μmol.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 Cu 2 O/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.