Facile synthesis of novel Mn-doped Bi4O5Br2 for enhanced photocatalytic NO removal activity

This study investigates the photocatalytic activity of a novel Mn-doped Bi4O5Br2 material prepared via a facile synthesis process. The experimental and theoretical results confirm that Mn doping enhances the efficiency of NO removal over a Bi4O5Br2 catalyst under visible light irradiation. The SEM (scanning electron microscopy), BET (Brunauer-Emmet-Teller), XRD (X-ray diffraction) analyses show that neither the surface morphology nor the phase of the photocatalytic material changes after the incorporation of Mn. The ESR (electron spin resonance) and UPS (Ultraviolet photoelectron spectroscopy) results show that the electrons in the CBM (conduction band minimum) can be directly captured by O2 to produce large amounts of •O2 radicals, and •OH radicals are formed via the route of •O2−→H2O2→•OH. The higher efficiency of Mn-doped Bi4O5Br2 is driven by the reduced band gap, widened visible light absorption range, higher intensity of visible light absorption, and enhanced separation efficiency of electrons and holes in this material compared with those of pristine Bi4O5Br2.