Study On Tribocatalytic Performance Of Tungsten Bronze Structure Compounds

Finding a new environmental remediation method in terms of dye degradation is very important in an industrialized society.In recent years,the triboelectric effect has shown great feasible in environmental remediation.Therefore,by collecting triboelectric energy,a tribo-catalytic dye degradation technology based on tribo-electro-chemical effects is designed.A series of tungsten bronze structure ferroelectric submicron powders were prepared by solid-phase reaction method,using X-ray diffraction analysis（XRD）,scanning electron microscope（SEM）,transmission electron microscope（TEM）,X-ray photoelectron spectroscopy（XPS）,Ultraviolet-visible spectrophotometer（Uv-vis）,electron spin resonance spectroscopy（ESR）and other methods were used to characterize the phase structure,morphology and catalytic performance of the prepared catalyst,and to explore its catalytic mechanism.Get the following conclusions:（1）The Ba₄Nd₂Fe₂Nb₈O₃₀（BNFN）submicron catalyst has high tribocatalytic activity.The degradation efficiency of rhodamine B dye reaches 97%after 2 hours of stirring and friction,and it shows good recyclability.The hydroxyl radicals（·OH）and superoxide radicals（·O₂^—）measured during the tribocatalysis process prove that triboelectric energy can excite BNFN to generate electron-hole pairs.（2）The Ba_2.5Sr_2.5Nb₈Ta₂O₃₀（BSNT）submicron powder catalyst can quickly degrade the dye in the solution under magnetic stirring.When the friction material is changed to a glass magnetic rod-polypropylene beaker,the degradation efficiency of rhodamine B can be significantly improved.Control experiments show that the friction between the BSNT submicron powder and the PTFE stirring rod induces charge transfer,induces a non-zero electric field inside the BSNT,and the electric field drives the separation of internal electron-hole pairs,which leads to the tribocatalytic degradation of the dye.The friction catalysis of the tungsten bronze submicron powder provides a novel and effective method for the degradation of wastewater dyes by using tiny mechanical energy.（3）The precious metal Ag is used as a co-catalyst to modify the BSNT submicron powder and conduct a catalytic degradation experiment.The results showed that the catalytic performance of the modified Ba_2.5Sr_2.5Nb₈Ta₂O₃₀@Ag（1.5wt%）was significantly improved,and the degradation efficiency increased from 96%to 99%.This is because Ag nanoparticles loaded on the surface of BSNT hinder the triboelectrically induced recombination of positive and negative charges.In addition,the obtained catalyst still has good stability after 3 cycles.