Iron‐Doped Bismuth Tungstate with an Excellent Photocatalytic Performance

Abstract

The metal‐doping of Bi‐based oxide photocatalysts to enhance the photocatalytic performance has been a research hotspot in recent years, but the research on the mechanism of doping‐induced photoactivity improvement is still incomplete. To illustrate the mechanism completely and clearly, Fe‐doped Bi2WO6, as an example, was synthesized by a facile hydrothermal route. Fe‐doped Bi2WO6 exhibits a much higher photoactivity than pure Bi2WO6 in the degradation of Rhodamine B (RhB) and salicylic acid (SA). By replacing W6+, the Fe3+ doping narrows the energy band gap and generates many oxygen vacancies, which can increase the adsorption of both RhB and SA, and the introduced defect and Fe‐doping energy levels in the band gap of Bi2WO6 increase the separation efficiency of photoinduced charge carriers significantly. These lead to the considerable photoactivity enhancement of Fe‐doped Bi2WO6. The photoactivity of Fe‐doped Bi2WO6 is stable and superior to that of most reported modified Bi2WO6 photocatalysts. This work illustrates in detail the mechanism for the photoactivity improvement of Fe‐doped Bi2WO6, which benefits the research of other metal‐doped photocatalysts.

Bi‐based photocatalysts for light‐driven environmental and energy applications: Structural tuning, reaction mechanisms, and challenges

“…The deposition and doping of metallic elements could change the photocatalytic properties mainly in the following two aspects. First, when metal ions enter the lattice, they will change the crystallinity of the Bi‐based photocatalysts or introduce defects, so as to enhance the absorption properties of light and the separation efficiency of photogenerated charges 137‐140 . For instance, Regmi et al synthesized Fe‐doped BiVO 4 with the in‐gap state between the valence band and conduction band of BiVO 4 , resulting in enhancing electron‐hole separation and improving the absorption capacity of visible light.…”

Synthesis and Enhanced Photocatalytic Activity of Rare Earth Ion (Ce3+, Nd3+, Pr3+ or Sm3+) Doped Bi2WO6 Microspheres for Rhodamine B Degradation

“…The value of n decides the type of electronic transition in a semiconductor ( n =1 for direct transition and n =4 for an indirect transition). For Bi 2 WO 6 , it is confirmed the value of n is 4 . Figure b shows the plots of hν versus ( αhν ) 0.5 .…”

Photocatalytic Detoxification of Antibiotic- and Bacteria-Contaminated Water using Cobalt-Doped Ni–Zn Ferrites Magnetic Separable Nanopowders

“…Because of its localized surface plasmon resonance effect (Braik et al 2021;Sinha 2021;Debnath et al 2021), the Co dopant can act as an electron reservoir and delayed the recombination of photoinduced charge carriers as validated by the results of the PL investigation. Also, the conversion between Co 3+ and Co 2+ (1.81 V vs NHE) gives priority to capture electrons, hence can inhibit electron-hole pair recombination (Hu et al 2018). Based on the results of the radical quenching studies, the • O2 − radicals and the photogenerated charge carriers can either directly degrade the adsorbed MZ or react with H2O2 in the system to form • OH radicals, as represented in Eqs.…”