构建高催化活性的BiVO₄@Ag复合材料

This study addressed the issues of high carrier recombination rates and sluggish surface reaction kinetics in bismuth vanadate(BiVO4) photocatalysts.Using spherical BiVO4 as the substrate, BiVO4@Ag-6% composite materials were constructed via three distinct photochemical reduction methods(direct reduction, silver-ammonia complex reduction, and potassium bromide-mediated reduction).The effects of different loading methods on the microstructure and photocatalytic performance of the materials were systematically investigated.The structure and properties of the composite materials were systematically characterized using transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),and electrochemical measurements.Experimental results indicated that the target material prepared via the potassium bromide-controlled reduction method exhibits superior catalytic activity.The AgBr complex-mediated Ag+ release mechanism significantly optimizes the dispersion and interfacial bonding strength of Ag nanoparticles(Ag NPs),resulting in optimal photocatalytic degradation activity for Cr6+ and Rhodamine B(RhB) with complete Cr6+ degradation within 20 min and a markedly enhanced RhB degradation efficiency compared to pure BiVO4.Characterization analysis attributes this superior performance to the synergistic effects of surface plasmon resonance(SPR) and the Schottky barrier in Ag NPs, which effectively suppressed carrier recombination and accelerate interfacial charge transport.