BiVO₄ Microspheres Coated with Nanometer-Thick Porous TiO₂ Shells for Photocatalytic Water Treatment under Visible-Light Irradiation

Abstract

Herein, we designed and synthesized well-defined BiVO4@porous TiO2 shell microspheres, with different core diameters by a facile hydrothermal method, for efficient visible-light-driven photocatalysis. The developed complex particles contained single solid BiVO4 cores and nanometer-thick porous TiO2 shells, composed of many nanosheets, and showed high stability and excellent photocatalytic activity for degrading both organic dyes and colorless organic contaminants under visible-light irradiation, much better than the benchmark of commercial P25 and bare BiVO4 microspheres of the same size. Compared to the bare BiVO4 microspheres, the BiVO4@TiO2 heterostructures showed improved photocatalytic activity, which was ascribed to (i) the formed BiVO4/TiO2 heterojunction with a defect energy level generated by the Ti3+ ions during the nanoporous TiO2 shell formation, which greatly promoted the charge carrier seperation and transfer between the BiVO4 and TiO2 during the photocatalysis process; (ii) the unique core@porous-shell structure that led to the intimate contact between the BiVO4 core and the TiO2 shell, facilitating the interfacial charge transfer; and also more importantly, (iii) the unique nanostructured porous TiO2 shell composed of numerous tiny TiO2 nanosheets that provided a large surface area for the easy adsorption of organic molecules and made the separated charge carriers directly available to the reactants, largely suppressing the charge carrier recombination and further increasing the photocatalytic efficiency. This study provides a feasible approach for the rational design of high-efficiency core@porous-shell nanostructured photocatalysts for photocatalytic water and wastewater treatment under visible-light irradiation.

Effects of environmental metal and metalloid pollutants on plants and human health: exploring nano-remediation approach

“…It has been widely studied how prokaryotic bacteria and actinomycetes may be used to synthesize metal and metal oxide NPs. Yet, during the production of Cd NPs, glutathione and cysteine desulfhydrase in E. coli have been largely responsible for the creation of spherical shapes (Eroglu and Metin 2023 ; Wang et al 2023a ). The ultimate size of the NPs may depend on how they interact with biologically active substances and whether they are located extracellularly or intracellularly (Thakkar et al 2010 ).…”

Composites of Ag-Doped ZnIn2S4 Nanoplates with Graphitic Carbon Nitride and Reduced Graphene Oxide Nanosheets for Sunlight-Driven Hydrogen Production and Water Purification

“…The g-C 3 N 4 /X wt % RGO/Y wt % AZIS nanocomposite (X represents the mass ratio of RGO, X = 0.75, 1.0, 2.0 and 3.0; Y represents the mass ratio of Ag/ZnIn 2 S 4 ; Y = 10.0, 20.0 and 30.0) was constructed by a two-step hydrothermal process. 24 First, to obtain the g-C 3 N 4 /0.75 wt %RGO composite, 150 mg of g-C 3 N 4 and 1.125 mL of GO (1 mg/mL) were dispersed in 50 mL of water under ultrasound for 1 h. The suspension was transferred into a 100 mL Teflon-lined stainless steel autoclave and then heated at 160 °C for 6 h. The product was then centrifuged, washed with water and ethanol three times, and dried in an oven at 80 °C for 12 h. g-C 3 N 4 /RGO composites with different mass ratios of RGO were synthesized by adjusting the volume of GO. Second, the g-C 3 N 4 /RGO/AZIS nanocomposite was synthesized.…”

Solvent-Free Synthesis of Cu/In Dual-Single-Atom-Doped TiO2 for Photocatalytic Reduction of Cr (VI) with High Efficiency

“…The synthesis of mesoporous TiO 2 mainly includes hydrothermal method, hard template method, phase change method, and sol–gel method . To control the rate of hydrolysis and condensation of TiO 2 , these methods usually require a large number of polar organic solvents.…”