Nanostructured MnO ₂ ‐Based Zn‐Doped Bi ₂ O ₃ Nanocomposite for Improved Antimicrobial and Photocatalytic Applications

Abstract This study reports the synthesis of MnO₂‐based Zn (5%)‐doped Bi₂O₃ nanocomposites via coprecipitation, highlighting significant improvements in photocatalytic and antimicrobial properties. XRD confirmed the tetragonal β‐Bi₂O₃ phase with reduced crystallite size postdoping, while FESEM showed spherical particles of 8.61 nm. A decreased band gap of 2.61 eV and defect‐related PL emissions were observed, enhancing photocatalytic activity. The material demonstrated 92.4% and 99.50% efficiency for methylene blue (MB) and rhodamine B (Rh.B) degradation under sunlight, outperforming undoped Bi₂O₃. The I–V plots revealed reduced electrical resistance and increased photosensitivity (8.58%), indicating potential in optoelectronic applications. Antifungal tests showed inhibition zones of 16 and 11 mm against Fusarium and Aspergillus , respectively. Compared to previous studies, this work offers improved photocatalytic and antifungal performance, attributed to the reduced crystalline size, increased surface area, and enhanced defect formation, positioning it as a promising material for environmental and biomedical applications.