Application of an Au/B-ZnO/PET–GR flexible composite structure in photocatalysts and supercapacitor electrodes

The Au/B-ZnO/PET–GR composite structure with different boron doping concentrations was prepared on a flexible double-layer substrate of PET–GR using the hydrothermal technique assisted by the ion sputtering method. With the increase of B doping content, the morphology of nano-ZnO evolved from nanorods (NRs) to nanosheets (NSs). The degradation rate of the Au/3% B-ZnO/PET–GR catalyst achieved the maximum value of 38.11%, and the reaction of degrading an RhB solution followed first order reaction kinetics. The photocatalytic activity of the composite structure was effectively increased by the proper incorporation of B atoms, and the photocatalytic mechanism of the samples was analyzed by energy band theory. The equivalent series resistance and specific capacitance at a scan rate of 5 mV s−1 of Au/3% B-ZnO/PET–GR electrode were 3.1 Ω and 62.96 F g−1. The effects of the substrate and metal layer on the electrochemical and photocatalytic properties of the composite structure were also investigated.