Recent advances in zinc oxide-based photoanodes for photoelectrochemical water splitting

Photoelectrochemical (PEC) technology has gained significant attention among researchers and scientists due to its potential for minimal greenhouse gas emissions, cost-effectiveness, and the production of green hydrogen energy. PEC technology enables solar energy conversion into hydrogen gas by utilizing sunlight and specialized semiconductors known as photoelectrochemical technologies. These technologies harness solar energy to split water molecules, generating both hydrogen and oxygen. Developing suitable materials is crucial for creating efficient and viable PEC systems. Among the various materials explored, metal oxides, including zinc oxide (ZnO), have garnered significant interest. ZnO is particularly attractive due to its affordability, environmental friendliness, and abundance on Earth along with its unique physical and chemical properties. Furthermore, it discusses modification techniques aimed at improving the efficiency of ZnO photoanodes, with a specific focus on synthesis techniques, including morphology control, defect engineering, and property optimization methodologies. Additionally, incorporating various elements and engineering heterostructures such as Type II and p-n junctions aims to enhance PEC performance. This comprehensive review is geared towards improving the comprehension of PEC technology, with a strong emphasis on core principles, applying ZnO as a photoanode, and strategies for enhancing ZnO-based photoelectrochemical systems.