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In this paper,V2O5 sol was firstly prepared using vanadyl sulfate as a vanadium source by modified sol-gel method at room temperature.Then flower-like V2O5 powders were prepared by coagulating as-prepared sol with anhydrous ethanol and subsequent annealing crystallization.The X-ray diffraction analysis indicated that V2O5 powders exhibited orthorhombic crystal structure after annealing at 450 ℃.The experimental data obtained from both field emission scanning electron microscopy and high-resolution transmission electron microscopy identified that V2O5 powders were approximately flower-like in shape and about 5 tm in size.Besides,the Brunauer-Emmett-Teller specific surface area of flowerlike V2O5 powders was 24.25 m2/g.According to Uv-Vis spectroscopy,the degradation rate of toluidine blue O (TBO) on as-prepared flower-like V2O5 powders during 10 h of visible light irradiation with an intensity of 15.4 mW/m2 was 88％,which was faster than those over P25 (46％) as a comparison.In addition,the mineralization process of TBO was investigated,which primarily consisted of demethylation and ring-opening oxidation processes,and confirmed by liquid chromatograph-mass spectrometry.The precipitation-oxidation-peptization,coagulation,and crystallization processes were proposed as the formation mechanism for the preparation of flower-like V2O5.