Effortless Fabrication of Bi 2 O 3 ‐Co 3 O 4 Nanocomposite Catalyst: Harnessing Photocatalytic Power for Efficient Cationic Dye Degradation

• Published in: ChemistrySelect (Weinheim) 2024-04, Vol.9 (13)
• Main Authors: Pradhan, Debapriya, Nayak, Nibedita, Kanar, Monalisha, Kumar Dash, Suresh
• Format: Article
• Language: English
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202400217

A cost‐effective and simple co‐precipitation approach was used to create an efficient photocatalyst Co 3 O 4 ‐Bi 2 O 3 with identical stoichiometry (1 : 1 of both Co 3 O 4 and Bi 2 O 3 ). XRD, FTIR, TEM, SEM‐EDS, XPS, UV‐DRS, PL, BET, and TGA were used to characterize the produced material‘s structural and optical properties. The presence of a single phase spinel structure with a distinctive plane (311) was verified by the XRD peak of 2 at 36.9° for Co 3 O 4 ‐Bi 2 O 3 . The SEM pictures revealed clustered consolidated spheres, suggesting particle homogeneity and high interconnectedness. The HR‐TEM and SAED pictures revealed an average crystallite size of 28 nm for the Co 3 O 4 ‐Bi 2 O 3 heterojunction. The UV‐DRS spectral data demonstrated a 2.1 eV reduction in band gap energy for Co 3 O 4 ‐Bi 2 O 3 (whereas Co 3 O 4 is 2.4 eV and Bi 2 O 3 is 2.7 eV). Under solar light irradiation, pristine Co 3 O 4 , Bi 2 O 3 , and Co 3 O 4 ‐Bi 2 O 3 composites were investigated for photocatalytic degradation of Methylene Blue (MB) and Malachite green (MG) dyes. By adjusting factors such as pH, starting dye concentration, catalyst dosage, and agitation duration, the optimal efficiency was determined. The acquired results showed Co 3 O 4 ‐Bi 2 O 3 ′s superior activity over both precursors. The composite obtained maximal degradation of 98 % (at pH=11) and 97 % (at pH=9) for MB and MG, respectively. The enhanced photo degradation activity of Co 3 O 4 ‐Bi 2 O 3 can be due to larger visible light absorption, increased surface area, and decreased h + /e − recombination. The reactive species trapping study was performed to determine the importance of superoxide and hydroxyl radicals during photo degradation. Dye degradation was governed by a pseudo‐first‐order kinetic model. The reusability and stability of Co 3 O 4 ‐Bi 2 O 3 were confirmed by utilizing the same material for five consecutive runs with both MB and MG dyes. Mass spectra analysis provided insights into the successful degradation of dyes, elucidating intermediate products. The synthesized Co 3 O 4 ‐Bi 2 O 3 nanocomposite offers unrivalled advantages in terms of structural and optical properties, superior photocatalytic activity, and remarkable stability, making it a promising candidate for efficient dye degradation applications without the formation of toxic by‐products.