Structure regulation and photocatalytic activity enhancement of Bi₂WO₆by “double‐effect modification” mode

Abstract

Summary In this paper, the Cl‐doped hollow microspherical Bi2WO6 nano‐photocatalyst was self‐assembly synthesized creatively by one‐step solvothermal method using the surface charge regulation strategy for electrostatic adsorption effect of anion in KCl and cation in polyvinylpyrrolidone (PVP). The crystal structure, morphology, element distribution, chemical state, and optical characteristic were, respectively, characterized. The reasons for improving the photocatalytic activity were investigated by degrading tetracycline hydrochloride (TCH). Combined with characterization analysis and the density functional theory (DFT theory), the “double‐effect modification” mode under the surface charge control strategy can not only successfully dope the Cl‐ to achieve functionalization of the product, but also achieve effective control of the product morphology through electrostatic self‐assembly process. The electron hole pair recombination was further inhibited, and the photocatalytic activity was improved. The proposed mode provides a simpler, more efficient and widely applicable method for the modification of Bi2WO6 to enhance its photocatalytic activity.

Shapes Control of Bi2WO6 Nano-Structures as Photo-Fenton Catalysts for Pulping Wastewater Treatment

“…As a typical Aurivillius oxide photocatalyst, Bi 2 WO 6 has been widely applied for mineralization of organic pollutants with UV light irradiation [22][23][24]. Thanks to its layered structure, Bi 2 WO 6 possesses outstanding intrinsic physical and chemical properties [25][26][27][28]. Up to date, the facile hydrothermal route is still the dominant method for the preparation of Bi 2 WO 6 photocatalyst, which affords a high crystallinity and size-controllable particles under mild conditions [27,[29][30][31].…”

Synthesis of “walnut‐like” BiOCl/Br solid solution photocatalyst by electrostatic self‐assembly method

“…The fluorescence emission of semiconductor is caused by the recombination of photogenic electron-hole pairs, 9 which is one of the effective methods to reveal the band structure, photogenic carrier life, and optical properties of semiconductor. 52 As shown in Figure 12, compared with nanometer piece before modification, fluorescence emission spectrum intensity of hollow ball BiOCl after being modified by PVP and citric acid is slightly lower, and fluorescence emission spectrum intensity of BiOCl/ Br solid solution after the incorporation of Br − is further reduced, especially the "walnut-like" BiOCl/Br, which possesses the lowest strength of a solid solution fluorescence spectrum.…”

“…However, BiOCl is a wide bandgap semiconductor with a bandgap of 3.19 to 3.44eV and a low utilization rate of visible light . For this reason, researchers have explored various modification methods to optimize visible light, such as morphology regulation, ion doping, semiconductor and composite . A lot of literatures have shown that doping of nonmetallic elements such as F, Br, I, C, N, and S can effectively enhance the photocatalytic performance of BiOCl semiconductors .…”

“…[5][6][7] For this reason, researchers have explored various modification methods to optimize visible light, such as morphology regulation, ion doping, semiconductor and composite. [8][9][10] A lot of literatures have shown that doping of nonmetallic elements such as F, Br, I, C, N, and S can effectively enhance the photocatalytic performance of BiOCl semiconductors. [11][12][13][14][15][16][17] Solid solution photocatalyst is different from simple element doping, which forms a new impurity energy level to reduce the bandgap.…”

“…For instance, the core‐shell structure, the unique synergy between the core and the shell structure will definitely give the material excellent performance . Electrostatic adsorption self‐assembly technology is a spontaneous assembly based on electrostatic adsorption force of opposite charges . This technology is simple, energy saving, and pollution free and provides a theoretical gist for exploring the formation mechanism of catalyst material form.…”