Electrochemical and photoelectrochemical degradation of Rhodamine B using a novel BHP@ZnO photoelectrode: Synthesis, characterization, and statistical study

This study focuses on the preparation of a novel photoanode by combining BAHPO4 (BHP) and ZnO, aiming to harness their synergistic impact on degrading Rhodamine B dye (RhB). Characterization involved X-ray diffraction (XRD), SEM-EDX morphological analysis, FT-IR vibrational analysis, and UV-Vis DRS optical analysis. Both semiconductors exhibited band gaps in the UV region, with ZnO at 3.1 eV and BHP at 3.9 eV. Electrochemical analyses, including Mott-Schottky (MS), open circuit potential (OCP), photocurrent (PT), and linear sweep voltammetry (LSV), were conducted. The electrocatalytic investigation of BHP@ZnO was optimized using statistical CCD-RSM analysis, identifying key parameters for improved degradation efficiency: applied current density, pollutant concentration, supporting electrolyte concentration, and pH. Remarkably, degradation efficiency achieved 100% within 30 min. Furthermore, photoelectrocatalytic experiments under UV light reduced degradation time to 8 min. Examination of trap states at the n-n junction of BHP@ZnO unveiled insights into the degradation mechanism, pinpointing •O2- as the primary radicals accountable. The photoanode demonstrated sustained stability and repeatability, showcasing its potential as a dependable and effective tool for RhB degradation. this study presents a promising approach utilizing BHP and ZnO within a novel photoanode, highlighting their synergistic effect in degrading RhB and contributing to the field of advanced photocatalytic materials. [Display omitted] •The BHP@ZnO photoelectrode was successfully synthesized and characterized.•The BHP@ZnO composite exhibited enhanced electrocatalytic and photo-electrocatalytic activity and stability.•The predominant reactive species for RhB dye degradation was confirmed to be •O2-radicals.•The mechanism was proposed based on the synergistic effect between ZnO and BHP.