Green synthesized zinc oxide nanostructures and their applications in dye-sensitized solar cells and photocatalysis: A review

The demand for clean energy and sustainable technologies has led to extensive research in the field of nanomaterials, particularly zinc oxide (ZnO) nanostructures, due to their unique properties and promising applications. This review focuses on the green synthesis methods of ZnO nanostructures, emphasizing eco-friendly and sustainable approaches that minimize environmental impact. Various green synthesis techniques, such as plant-mediated, biological, and environmentally benign chemical methods, are discussed, highlighting their advantages over conventional processes. Moreover, the review explores the applications of ZnO nanostructures in dye-sensitized solar cells (DSSCs) and photocatalysis. DSSCs represent a prominent alternative to traditional solar cells, and the integration of ZnO nanostructures as photoanodes holds great potential for enhancing efficiency and performance. The underlying mechanisms of ZnO nanostructures in DSSCs are examined to provide a comprehensive understanding of their role in photovoltaic applications. Additionally, the photocatalytic properties of ZnO nanostructures are investigated, with a particular focus on their ability to degrade organic pollutants and their potential in wastewater treatment and air purification. The photocatalytic mechanisms and factors influencing the efficiency of ZnO nanostructures in these processes are critically analyzed. In conclusion, this review presents an overview of the state-of-the-art green synthesis methods for ZnO nanostructures and discusses their applications in DSSCs and photocatalysis. The environmentally friendly nature of these synthesis approaches and the multifunctional capabilities of ZnO nanostructures make them promising candidates for sustainable energy conversion and environmental remediation technologies. However, challenges and future prospects in the field are also highlighted to guide further research and development in this area.