Synergistic effects of pH and calcination temperature on enhancing photodegradation performance of m-BiVO 4

Abstract

Abstract Photocatalytic degradation of organic dyes is a promising alternative to current conventional pollution-free technologies. Herein, the visible-light-driven m-BiVO4 photocatalysts with enhanced photodegradation performance were successfully synthesized via solid–liquid state reaction. The photodegradation performance of as-prepared m-BiVO4 photocatalysts via removal of methylene blue dye under visible light irradiation were evaluated by adjusting pH (1, 3, 6, and 10) and calcination temperature (400, 500, and 600 °C). In addition, a mathematical representation for understanding the interaction between pH and calcination temperature for photodegradation of methylene blue using response surface methodology (RSM) was successfully generated. The m-BiVO4 photocatalysts prepared at pH 1 and then calcined at 500 °C exhibited superior photodegradation performance with 98.5% rate of removal within 3 h. The XRD peaks confirmed that the as-prepared m-BiVO4 were in agreement with standard monoclinic scheelite structure. Moreover, the intensification of FTIR spectra of mBV500 revealed that coupling calcination treatment with pH helps to generate more active site traits, resulting in better photodegradation performance. The better crystallinity of mBV500 shown in FESEM micrographs and sharp deconvolution of XPS peaks signified the decent synergy between optimum pH and calcination temperature. The synergistic effect between optimum pH and calcination temperature also effectively averted the fast recombination rate of electron-hole pairs by minimizing the band gap energy as revealed in DR–UV–Vis measurements.