Eco-friendly recovery of ZnO from alkaline batteries for photocatalytic water treatment

One viable solution to the present material shortages is the transformation of old electronics. Through eco-friendly and facile methods, our work demonstrates that old alkaline batteries can be transformed into effective zinc oxide materials. This method promotes a regenerative economic model that can satisfy the rising demand for high-tech materials while simultaneously reducing the negative effects of waste management. Even though reaction durations gradually increased due to surface fouling, ZnO-C3N4 demonstrated excellent long-term durability across four successive photocatalytic cycles. It was able to successfully remove over 99.3 % of methylene blue (MB) and over 99 % of crystal violet (CV). This was accomplished despite the fact that surface fouling caused the reaction times to gradually increase. The pH levels had a significant impact on the function of the catalyst, with degrading efficiency increasing from acidic to alkaline conditions. The catalyst reached its greatest effectiveness between pH 9 and 11, when it was able to remove nearly all of both dyes (99.47 to 99.81 % for MB and 99.21 to 99.6 % for CV). These findings underscore the strong reusability and pH adaptability of ZnO-C3N4. This study reveals that ZnO-C3N4 is a promising application for water remediation, especially dye waste.