Synthesis and high efficiency of photocatalytic sensing via zinc-oxide nanorods decorated with gold nanoparticles

Synthesizing zinc oxide Nanorods decorated by gold nanoparticles (ZnO-Au NRs) has been reported; the method involves growing ZnO NRs by CVD (Chemical Vapor Deposition) reactions and then decorating the produced ZnO NRs using Au nanoparticles via DC sputtering method. Measurements of optical absorption were used to analyze the optical characteristics. FESEM (field-emission scanning electron microscopy), AFM (Atomic force microscopy), and XRD (X-ray diffraction) were used to characterize both the structure and morphology of the synthesized materials. ZnO NRs have a polycrystalline wurtzite hexagonal structure, and Au nanoparticles, exhibiting FCC (face-centered cubic structure). The ZnO-Au NRs demonstrated good absorbency in the visible and ultraviolet spectral regions, indicating efficient production of electron-hole pairs by light stimulation. The ability of these Nanorods to detect ethanol concentrations in a vacuum ranging from 125 to 500 ppm was investigated. Au decoration on ZnO nanorods has been observed to improve their gas-sensing response, which exhibited high-efficiency sensing. Where catalytic properties of Au nanoparticles enhance reaction rates and response times in chemical sensitization. In addition, when gas oxidation occurs at the surface of ZnO Nanorods, the conductivity of the metal-decorated ZnO nanorods changes upon exposure to ethanol, leading to an improvement in their gas-sensing performance.