Design of NiCo2O4 (NiCo oxide) embedded polysulfone membrane for high-performance MB photocatalytic removal through response surface methodology and DFT

Abstract

The photocatalytic efficacy of the flexible membranes was assessed on the methylene blue (MB) under sunlight irradiation. Flexible membranes including polysulfone (PSF) with nickel cobalt NiCo2O4 (NiCo oxides) at different concentrations (0%, 0.25%, 0.5%, 1%, and 1.5% wt). NiCo oxides were synthesized using the co-precipitation method and were embedded into the PSF membrane through the phase inversion method with 250 μm as the thickness. The flexible membranes were characterized through SEM, XRD, FTIR, and EDX modalieties, as well as mechanical strength and contact angle methods. The bandgap was reported to be enhanced from 3.861 to 3.794 eV for M0 and M3, respectively, demonstrating remarkable overall photocatalytic activity. The membrane with 1.5 wt% NiCo oxide (M3) showed the maximum efficacy, 100% MB degradation after 5 h. The optimized parameters such as pH, dose, and contact time, were evaluated on the degrading efficiency of M3, with an efficiency of 99% at pH 9 (and 99% after five cycles for MB under sunshine irradiation), proving stability and recyclability. Further, functional treatment (DFT) was utilized to validate the effectiveness and dependability of the proposed PSF/NiCo oxides membrane in evaluating the application value of photocatalysts. Finally, the optimization of the process parameters was verified experimentally using the response surface methodology. The results of the validation experiment determined a very close agreement with the predicted photocatalytic activity.