Enhanced Photocurrent Generation of Graphene/Au@ZnO Honeycomb Film

A bio-inspired graphene/Au@ZnO photoelectrode has been prepared via breath figure method, in which Au@ZnO nanospheres were uniformly distributed in the whole honeycomb film. The size of the honeycomb holes effects the light using efficiency. The honeycomb film with smaller holes in more ordered array shows better antireflective property. All the formed graphene/Au@ZnO honeycomb photoelectrodes show a fast, stable, and reversible response of photocurrent accompanied by each switch-on and switch-off event. Au@ZnO-modified graphene honeycomb film can combine the advantages of increased light harvesting provided by honeycomb structure, efficient charge separation from Au nanoparticles (NPs), and efficient electron transfer provided by graphene. Au@ZnO- modified graphene honeycomb film shows a two-fold increase of photocurrent generation than ZnO-modified graphene honeycomb film and a three-fold increase of photocurrent generation than Au@ZnO-modified graphene smooth film, respectively. The rational design and engineering of multi components with different functions in a hybrid bio-inspired structure hold great promise for further efficient solar energy conversion devices.