Effect of halide counterparts on the visible light driven photocatalytic efficiency of Bi0/Bi₅O₇I defective nanophotocatalysts

Various [Bi 2 O 2 ] 2− layered BiOX nanophotocatalysts were synthesized via the hydrothermal approach, contrasting with the generation of oxygen vacancies in Bi 5 O 7 I nanocatalysts by the in situ reduction of Bi 3+ to Bi 0 metallic nanoparticles. Surface defects and the presence of metallic Bi nanoparticles were confirmed by XPS, Raman spectroscopy, and XRD analyses. The morphological analysis further confirmed the dispersion of metallic Bi nanoparticles dispersed over the surface of the Bi 5 O 7 I nanocatalysts. The metallic Bi acted as the electron sink and reduced the photogenerated charge carrier recombination, enhancing the photocatalytic efficiency. The presence of oxygen vacancies and the porous structure confirmed by the BET analysis, which enhanced the degradation efficiency. The optimized experimental conditions demonstrated a 1.67 -fold enhanced rate of acid red 1 (AR1) degradation in the presence of Bi 5 O 7 I nanocatalysts (9.38 × 10 −4 s −1 ) when compared with the commercial Degussa P25 (5.62 × 10 −4 s −1 ). Various bismuth oxyhalides, such as Bi 3 O 4 Cl, Bi 4 O 5 Br 2 , and Bi 2 O 3 nanocatalysts were experimented against AR1 degradation, and Bi 5 O 7 I exhibited superior degradation. The influence of halides on [Bi 2 O 2 ] 2− layers were monitorted. The ROS responsible for the enhanced degradation were evaluated through the scavenging studies, whereas the mineralization of AR1 was confirmed using the HRMS QTOF analysis. • Bi 0 decorated Bi 5 O 7 I nanoarchitecture resulted from hydrothermal approach. • Bi 5 O 7 I.nanoarchitecture demonstrated 96 % of AR1 degradation in 60 min. • Bi 0 nanoparticle augmented the degradation efficiency of Bi 5 O 7 I. • Photobleaching resulted in 12 min of simulated solar light- irradiation. • Complete mineralization was attained in one hour of solar-irradiation.