Sustainable synthesis, amplified efficacy: doped ZnO nanostructures driving photocatalytic excellence for wastewater remediation- A comprehensive review

This comprehensive review explores synthesis methodologies for ZnO nanostructures, emphasising green synthesis and doping techniques. Researchers, driven by environmental sustainability, have utilised various bio-reducing agents in synthesising both pristine and doped ZnO nanostructures. The study delves into the involvement of these structures in photo-assisted degradation of organic pollutants, showcasing the pivotal role of green-synthesised ZnO and its doped derivatives in photocatalysis. The review meticulously details alterations induced by dopants in the parent ZnO structure, highlighting their potential to enhance dye degradation efficiency. Mechanisms underlying the green synthesis approach are elucidated, exploring the interplay between surface reactions, photo energy, charge carriers, and energy band structures. Additionally, the synergistic effects of dopants on ZnO nanostructures when exposed to light are outlined, impacting various organic pollutants such as dyes, antibiotic effluents, organic solvents, and Polycyclic Aromatic Hydrocarbons (PAHs). Drawing from recent research papers predominantly from 2018–24, this review is a consolidated source on the current state-of-the-art. Its focus on doped ZnO nanostructures, commitment to sustainable synthesis, and exploration of efficiency augmentation through doping techniques distinguish it. Beyond summarising advancements, the review addresses future possibilities and challenges, significantly contributing to understanding photocatalytic excellence in green-synthesised ZnO nanostructures.