Plasma electrolytic formation and characterization of MnWO_(4)/WO_(3) film heterostructures  

作　　者：M.S.Vasilyeva I.V.Lukiyanchuk Yu.B.Budnikova V.G.Kuryavyi D.H.Shlyk G.A.Zverev 

机构地区：[1]Department of Chemistry and Materials of Institute of High Technology and Advanced Materials,Far Eastern Federal University,FEFU Campus,Vladivostok 690922,Russia [2]Institute of Chemistry,Far Eastern Branch,Russian Academy of Sciences,Vladivostok 690022,Russia

出　　处：《ChemPhysMater》2024年第3期293-302,共10页化学物理材料（英文）

基　　金：supported by the Institute of Chemistry FEB RAS State Order(Project No.FWFN(205)-2022-0001).

摘　　要：MnWO_(4)/WO_(3) p-n heterojunction films were fabricated using a one-step method consisting of the plasma electrolytic oxidation(PEO)of titanium in homogeneous electrolytes containing paratungstate ions and stable watersoluble EDTA-chelated manganese.The influences of the formation current density and W:Mn molar ratio of the electrolyte,which was varied from 1:2 to 2:1,on the composition,morphology,and optical and photocatalytic properties of the resulting coatings were studied.X-ray diffraction analysis,scanning electron microscopy,energy dispersive X-ray analysis,Raman spectroscopy,and ultraviolet diffuse reflectance spectroscopy were used to characterize the formed composites.Regardless of the W:Mn ratio of the electrolyte,the coatings contained crystalline t-WO_(3) and m-MnWO_(4).Depending on the formation conditions,the optical band gap energies of the composites varied from 2.63 to 3.01 eV.The largest absorption red shift and lowest band gap energy were observed in the film composite formed in an electrolyte with W:Mn=2:1,at a current density of 0.2 A cm^(−2).Composites obtained in electrolytes with W:Mn ratios of 2:1 and 1:1 exhibited photocatalytic activity in the degradation of rhodamine C and methyl orange dyes in the presence of 10 mmol L^(–1) H_(2)O_(2) under ultraviolet and visible light irradiation.The role of hydrogen peroxide in this dye degradation on PEO-coated composites under light irradiation is discussed.

关 键 词：Plasma electrolytic oxidation Manganese tungstate Tungsten oxide Titanium Optical properties p-n heterojunction 

分 类 号：O53[理学—等离子体物理]