Au-decorated 2D graphitic carbon nitride (g-C₃N₄)-coated ZnO nanorods for improved UV photodetection application

Two-dimensional (2D) material-based nanocomposites are fascinating for the development of ultrathin optoelectronic devices with superior efficiency. Here, we report the ultra-violet (UV) photodetection characteristics of nanocomposite made of Au-decorated 2D graphitic carbon nitride (g-C 3 N 4 )-coated ZnO nanorods. The Au nanoparticles (NPs) have been developed on g-C 3 N 4 nanosheets using the simple chemical route, while the nanocomposite with ZnO nanorods has been obtained using a cost-effective hydrothermal method. The 2D nature has been visualized through atomic force microscopy (AFM), while the existence of Au NPs has been confirmed from the plasmonic peak in absorption spectroscopy. The coating of ZnO nanorods with the net-like sheet has been observed in field emission scanning electron microscopy (FESEM). The as-synthesized nanocomposite has been found to be efficient for UV detection due to the presence of Au NPs. The type II heterojunction formed at the g-C 3 N 4 /ZnO interface facilitates charge transfer during UV illumination, while the Au NPs help to concentrate the UV radiation by increasing the oscillator strength of the system.