Adsorption and Photocatalytic Properties of α‐Bi2O3 for an Integrated Approach to Enhance Water Remediation From Dyes

The presence of persistent pollutants in freshwater effluents highlights the urgent need for multifunctional materials that can integrate efficient capture and degradation of pollutants within a single platform under mild conditions. Here, we present a multifunctional α-Bi2O3 material capable of acting as an adsorbent and a photocatalyst for efficient dye removal. The material, synthesized via an aqueous-mediated route, exhibits pronounced affinity toward Nile Blue under acidic conditions (pH < 4), while retaining intrinsic photocatalytic activity under UV–visible-light irradiation. At neutral pH, standalone photocatalysis achieves moderate degradation (ca. 60%); by integrating a preadsorption step (at pH = 3) followed by irradiation of the pellets, it achieves an enhancement of dye removal efficiency up to 90%. After multiple reuse photocatalytic cycles, α-Bi2O3 maintains structural integrity and high activity, highlighting robustness and operational resilience. This work establishes α-Bi2O3 as a versatile material for sustainable water remediation, combining high contaminant capture and efficient photooxidative degradation.