Non-TiO2-based photoanodes for photoelectrocatalytic wastewater treatment: electrode synthesis, evaluation, and characterization†

To address the increasingly serious problem of water pollution, photoelectrocatalysis (PEC), one of the advanced oxidation processes (AOPs), has gained significant attention due to its ability to utilize sunlight and its low energy consumption. In PECs, TiO₂ is the most widely used and established photoanode; however, non-TiO₂-based photoanodes have increasingly become a focus for improving visible light utilization and meeting the requirements of specific reactions. The performance of these non-TiO₂-based photoanodes in wastewater treatment varies based on different synthesis strategies and structures. Therefore, this paper critically reviews the synthesis, evaluation and characterization methods of non-TiO₂-based photoanodes used in wastewater treatment. Specifically, it reveals the application potential of various non-TiO₂-based photoanodes (such as WO₃, ZnO, g-C₃N₄, and BiVO₄), compares the costs and electrode stability of different synthesis methods from a practical application-oriented perspective, elucidates the synthesis–structure–mechanism–activity relationship, proposes an evaluation framework for PEC wastewater treatment based on multiple dimensions (including pollutant removal, electrode stability, light utilization efficiency, and environmental applicability), and introduces frontier theoretical simulations and characterization techniques of PEC wastewater treatment in depth according to the reaction process. Finally, an outlook on the preparation, evaluation and characterization of non-TiO₂-based photoanodes is proposed, covering perspectives from the atomic level to large-scale applications. This work aims to provide a comprehensive understanding of these ‘rising stars’ and guide the synthesis of photoanodes with enhanced performance, as well as more accurate evaluation and characterization.