Examining the photoelectric properties of hexagonal prism-shaped ZnO based on density functional theory

In this study, hexagonal prism-shaped ZnO with exposed (002) and (200) planes is synthesized by using the hydrothermal method, and XRD and SEM images are used to confirm the results. Density functional theory (DFT) was used to simulate the characteristic adsorption species (CAS) of the hexagonal prism-shaped ZnO, and this revealed the mechanism of the CAS on the crystal surface. The results of simulations showed that O-2 and H2O molecules were chemically adsorbed on the (002) and (200) planes, respectively. As the rate of coverage of the (002) plane by oxygen molecules increased, its photocurrent and conductivity significantly increased, while the photocurrent spectrum moved to the direction of the long wave and appeared to have two peaks. The photo -current and conductivity on the (200) plane did not change significantly with the increase in the rate of coverage by H2O molecules. The results of the theoretical simulations were consistent with the experimental results for the photocurrent spectrum. Therefore, the hexagonal prism-shaped ZnO can be used to detect reduced gas molecules by consuming adsorbed oxygen or using the photocurrent spectrum in gas-sensitive detection through a redox reaction.

Automated summary

In this study, hexagonal prism-shaped ZnO with exposed (002) and (200) planes was synthesized and its characteristic adsorption species and photocurrent spectrum mechanism were investigated through experimental and theoretical simulations. The results showed that hexagonal prism-shaped ZnO can be used for gas-sensitive detection by consuming adsorbed oxygen or using the photocurrent spectrum to detect reduced gas molecules.