Engineering yttrium doped CuO/BiOBr heterostructures with tunable electronic structure for multifunctional environmental remediation and antibacterial activity

Contamination of water by the effluents containing industrial dyes and pathogens is still a major environmental and public health concern, prompting the development of multifunctional materials that can solve these problems concurrently. Although CuO/BiOBr heterostructures and rare-earth metal doping have been previously reported to boost photocatalytic efficiency, literature reporting Y 3+ -doped CuO/BiOBr was not present. So, this study endeavored novel synthesize of Y-doped CuO/BiOBr nanocomposites and investigated how Y 3+ concentration influenced the structural, optical, dielectric, electrochemical, photocatalytic, and antibacterial behavior of the materials synthesized. Y-doped CuO/BiOBr nanocomposites were prepared using a one-step solvothermal route with Y concentrations varying from 0 to 5 wt%. X-ray diffraction analysis confirmed the formation of a two-phase structure consisting of the monoclinic phase of CuO and tetragonal BiOBr, with the crystalline grain size reducing from 15.77 nm to 8.87 nm due to increase of Y 3+ doping. The optical studies indicated a small band gap change from 2.66 eV to 2.79 eV with Y doping, and morphological investigations revealed a decrease in grain size from 301 nm to 251 nm along with an increase in porosity from 20.87% to 39.92%. The AC conductivity was improved from 0.877 × 10 −3 to 2.10 × 10 −3 S/cm, and the frequency exponents of 0.41 to 0.50 indicated correlated barrier hopping. The photocatalytic performance of the synthesized compounds was studied using the degradation of indigo carmine, where the degradation efficiency of the undoped composite was found to be 97.54%, and the 4 wt% Y-doped composite had the highest kinetic rate constant value (k = 0.191 min −1 ). Agar well-diffusion antibacterial studies against E. coli, K. pneumoniae, S. enterica, and S. aureus bacteria demonstrated that the zone of inhibition for the 4 wt% Y composite was 29 mm, and hence it possessed strong antibacterial activity.