Intelligently assembly of W₁₈O₄₉ nanorod clusters with directionally generated oxygen vacancies and excellent electrochemical properties

Mixed-valence metallic compounds are a class of functional materials with peculiar electrochemical properties. Exploring the correlation between defects and corrosion resistance of mixed-valence metallic compounds is a novel and interesting subject. Through an intelligently designed synergistic process of reduction and directed assembly, not only the directional generation of oxygen vacancies along the normal direction of the (010) crystal plane was achieved, but also the W₁₈O₄₉ mixed-valence metal oxide (MVMO) with a single crystalline phase and an assembled ordered three-dimensional cluster structure of nanorods was obtained. Three attractive effects of oriented oxygen vacancies in W₁₈O₄₉ MVMO were discovered. First, the oxygen vacancy channels realized the directional concentrated transport of oxygen atoms to form dense oxide passivation film. Second, the directional concentrated oxygen vacancies as active centers effectively solved the problem of difficult photoelectron leap and separation of pure-phase semiconductors, realizing photogenerated cathodic protection. Third, the high-energy vacancies endowed the material with antibacterial function, which contributed to the stable existence of the anti-corrosion system. The resistance value of W₁₈O₄₉ MVMO as an anti-corrosion functional material was increased to more than 4.00 times that of the original metal protection layer. The experimental results obtained in this research were of great reference value for revealing the intrinsic mechanism of correlation between oxygen defect orientation of MVMOs and electrochemistry.