This review emphasizes the pivotal role of etching strategies in refining structures and properties crucial to photocatalysis, a sustainable solution for energy and environmental remediation. As fossil fuel-related environmental concerns rise, photocatalysis emerges as a vital alternative. Yet, maximizing its efficacy is an ongoing challenge. Etching strategies, by creating structural vacancies and revealing active crystal facets, enhance light absorption and the catalyst's efficiency. This process effectively reshapes nanostructures, elevating their surface specificity and subsequently their catalytic properties. Despite advancements, few comprehensive reviews detail etching's influence on photocatalysts. This work, therefore, sheds light on how different etching methodologies affect photocatalyst structures and functions, covering mechanisms such as morphology control, surface area boosting, defect engineering, and more. Furthermore, the impact of etching on light absorption, charge dynamics, and reactant interactions is explored. The review concludes by pointing out challenges and the prospective growth of etching in photocatalysis. By deepening the understanding of etching modification, this review aims to drive progress in developing superior photocatalytic materials, thus fostering advances in renewable energy technologies.