Interface engineering of Zn3V2O8 decorated hydroxyapatite nanocomposite for photocatalytic degradation of Congo red dye and anti-microbial applications

Abstract

This study presents the synthesis of a new nanocomposite named Zn₃V₂O₈/hydroxyapatite (ZnV/HAP) to assess its photocatalytic efficiency for degrading Congo red dye (CR) under visible light. The nanocomposite was analyzed using various techniques, including FT-IR, XRD, UV-vis DRS, SEM, TEM, EDAX, XPS, and BET analysis. The photocatalyst's performance was enhanced by a shift in its band gap to 1.7 eV, compared to similar materials. ZnV/HAP exhibits superior photocatalytic performance compared to ZnV particles. The rate constant for the degradation of CR by ZnV/HAP was determined to be 0.0063 min⁻¹. The degrading efficiency of the ZnV/HAP composite is 94%. The enhanced charge separation in the ZnV/HAP composite is attributed to the strong contacts between the interfacial surfaces, which are responsible for their higher activity. A method was found to facilitate this heightened activity, with hydroxyl and superoxide radicals serving as crucial reactive species that significantly contribute to the photocatalytic process. The phytotoxicity investigation conducted on Vigna radiata plants demonstrated the photocatalytic effectiveness of the ZnV/HAP combination. In addition, the deteriorated CR dye solution exhibited a color removal efficiency of 94.62% for total organic carbon (TOC) and 92.86% for chemical oxygen demand (COD). The findings demonstrate that the synthesized ZnV/HAP is a viable substitute for visible-light-driven photocatalysts. Furthermore, the antimicrobial efficacy of ZnV/HAP was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger, demonstrating remarkable antibacterial and antifungal properties comparable to the positive control medication.