Sparking a comparative study between selective Bi-based photocatalysts (BiOCl, Bi12O17Cl2, and CuBi2O4) depending on their photocatalytic characteristics and degradation activity
摘要
Bismuth-based photocatalysts have become one of the most widely investigated materials in the photocatalytic fields. In this work, common bismuth-based photocatalysts (BiOCl, Bi12O17Cl2, and CuBi2O4) were perfectly synthesized, and their photocatalytic characteristics were examined and compared over different characteristic technologies (XRD, FT-IR, SEM, TEM, BET, DRS, PL, and EIS). Furthermore, the photocatalytic activity was performed for malachite green (MG) and tetracycline (TC) degradation under LED radiation. Compared with other catalysts, the CuBi2O4 exhibited the strongest light absorption towards visible and near-IR regions because it has the narrowest bandgap energy (1.62 eV). However, the small bandgap energy of CuBi2O4 promoted the charge recombination rate and hindered their catalytic performance. Besides, the Bi12O17Cl2 catalysts reflected the highest MG and TC degradation efficiencies of 72.5% and 65.7%, respectively. This is due to the moderate bandgap energy of Bi12O17Cl2 (2.63 eV), acceptable light absorption, and higher photocarrier separation rate. Moreover, the perfect band structure of Bi12O17Cl2 allows it to produce •OH radicals, accelerating the MG and TC degradation rate. The trapping tests revealed the ability of BiOCl and Bi12O17Cl2 to yield •OH, while the CuBi2O4 obtained strong CB potential to produce •O2−. Meanwhile, all synthesized photocatalysts returned good recyclability performance after five cycles. Finally, the photo-destruction mechanism has been elucidated through optical, electrochemical, and trapping tests. This work offers valuable insights into tailoring bismuth-based photocatalysts for improved catalytic behavior, paving the way for innovative approaches in sustainable energy and environmental remediation technologies.