Strategies to Boost Photocatalytic Degradation of Emerging Contaminants Using ZnO Heterostructure Photocatalysts

Industrial modernization has generated a wide range of toxic contaminants in industrial wastewater and domestic effluents. The increasing presence of emerging contaminants and endocrine disruptors in aquatic environments poses serious threats to ecosystems and human health. Accordingly, effective strategies are urgently needed for the removal of emerging organic pollutants, including dyes and antibiotics in pharmaceutical wastewater. Photocatalysis has attracted considerable interest as a versatile and sustainable remediation approach because photocatalysts are often cost-effective, earth-abundant, and capable of utilizing solar energy. This review summarizes recent advances in ZnO-based photocatalysts, focusing on compositional tuning and heterostructure engineering to enhance pollutant degradation. The major photocatalytic degradation mechanisms are also discussed. Despite significant progress, challenges remain, including limited light absorption, poor catalytic stability, and obstacles to practical application in wastewater treatment. This review provides an updated perspective on the development of ZnO-based photocatalysts for emerging pollutant removal.