Photochemical And Photoelectrochemical Properties Of TiNbO₅Nanosheet And Its Intercalated Composites

Utilizing solar energy to solve the environmental pollution problem is one ofimportant issues, which our mankind should face and undertake in21century.Utilizing the photocatalytic and photoelectrocatalytic technology, one can degradeatethe organic pollutants in water directly.Potassium titaniobate, KTiNbO₅, was prepared through solid state reaction, whichpresents a lamellar structure and a photocatalytically activity under UV irradiation.After exfoliation, the nanosheets has an extremely small thickness of1.05nm andlateral size ranging from submicrometers to several tens of micrometers, and thesestructure features are expected to evolve novel electrochemical andphotoelectrochemical properties.（TiNbO₅nanosheet）_n and-Fe₂O₃electrodes wereprepared through layer-by-layer method. The TiNbO₅-UV and Fe₂O₃-HTiNbO₅wereprepared by exfoliation and restacking technology. After XRD, SEM, TEM, AFM,TG/DTA, UV-Vis DRS, BET, electrochemical and photoelectrochemical examination,we analysised the materials’structure and compostion. The photocatalitic tests wasalso operated.（TiNbO₅nanosheet）_n electrode behaves the n-type semiconductor characteristics.Both conduction band were decided as-0.76V （vs NHE） through photoelectron-chemical experiments. In the degradation of RhB, when the electrode was irradiatedby visible light or UV light, the perfect degradation ratio would be deserved to（TiNbO₅nanosheet）_n used as anode or cathode respectively.The band-gap of TiNbO₅nanosheet is3.76eV, which means it can be excited byUV light （＜330nm）. After C-doped or coupling with-Fe₂O₃, the band-gap ofTiNbO₅-UV and Fe₂O₃-HTiNbO₅were reduced to2.72and2.35eV respectively, bothof them have stronger absorbance at visible light. The gallery height of thenanocomposites was about0.87and1.05nm respectively. The specific surface areawas determined as87and103m2/g each. The results of TG/DTA consider that thepillared material can preserve stable under high temperature.Fe₂O₃-HTiNbO₅has the pillared structure, accompanying the house-of-cards typestacking structure which demonstrated different pore size. And these structure make RhB can cross the pore and adsorb on the catalysis’s surface easily. At the same time,the complex of nanosheets and Fe₂O₃changed the transfer ways of the electrons in thecatalytic reactions, and improve the catalytic activity.