Facile synthesis of Cu doped ZnO-graphene oxide nanocomposites hybrid photoanodes for enhanced photoelectrochemical activity

A hydrothermal technique was used to synthesize copper (Cu) doped (0–2 at.%) ZnO-Graphene oxide nanostructure (Cu:ZnO-GO). A thorough investigation using XRD and SEM revealed that ZnO nanoparticles with a good crystallinity had formed on GO sheets. Cu:ZnO-GO has a lower optical band gap than undoped ZnO, which is 3.21 eV. Hence, the intensity of PL emission has reduced as Cu ion abundance in ZnO has increased. Studies on the photoelectrochemical (PEC) sensitivity were conducted. The maximum photocurrent density was seen in the doped ZnO-GO with 0.5 wt% Cu. The maximal photocurrent density for Cu:ZnO-GO was 58 µA/cm². This was 3 times greater than the same observed by undoped ZnO-GO value. The optimal doping content, that decreased recombination velocity, extended PL intensity was attributable to the low doping concentration added (0.5 at.%) in ZnO-GO.