A review on ZnO, Ag2O and Ag2O-ZnO composites for water remediation, anti-oxidant and anti-enzymatic applications

Functional materials, characterized by their unique physical, chemical, biological, and mechanical properties, play a pivotal role in advancing modern technologies. Among the plethora of functional materials, zinc oxide (ZnO) and its composites have emerged as promising candidates due to their versatile applications and exceptional properties. In particular, the composite of ZnO with silver oxide (Ag 2 O) holds significant potential, attributed to the synergistic interplay between their well-matched band structures. This alignment facilitates efficient separation of photoinduced electron-hole pairs, a critical factor in enhancing the material's functional performance. The morphology of these materials further influences their characteristic properties, enabling diverse functionalities. Consequently, understanding the relationship between structural attributes and performance is pivotal for optimizing their applications. The synthesis methods used to prepare these functional materials also play a crucial role in determining their morphology, efficiency, and sustainability. Among various techniques, the chemical co-precipitation method, especially when augmented with ultrasonication or microwave assistance, stands out as a high-yielding, safe, environmentally sustainable, and cost-effective approach. The functionalities of ZnO, Ag 2 O, and their composites extend across numerous domains. However, this study focuses on their photocatalytic, antibacterial, antioxidant, and anti-enzymatic activities, all of which fundamentally rely on the generation of reactive oxygen species (ROS). The intrinsic and extrinsic properties of these materials significantly influence their ROS generation and subsequent activity. This comprehensive exploration aims to unravel the intricate interplay of synthesis, morphology, and functionality, emphasizing how ZnO, Ag 2 O, and their composites are shaping advancements in technology and science.