Nghiên cứu khả năng quang xúc tác của BiNbO4 phân hủy metyl da cam dưới ánh sáng trong vùng khả kiến

Abstract

BiNbO₄ nanopowders prepared by combustion urea gel method were tested photocatalytic degradation under visible – light irradiation for methyl orange solution. BiNbO₄ were synthesized in optimal conditions, such as molar ratio Bi/Nb/urea  = 1/1/6, pH 1, gel is formed after calcination on temperature of 120°C for 4 hours and calcination temperature from 550 ^oC to 1050 °C for 2 hours. The prepared samples were characterized by X-Ray diffraction, field emission scanning electron microscopy, thermal gravimetric and differential thermal analysis and ultraviolet-visible light spectrophotometry. The effect of calcination temperature on phase formation and methylene orange degradation were investigated.  The result shows that the synthesized BiNbO₄ for the optimized sample have size that smaller than 70 nm. Also decomposing methyl orange solution illumination for 2 hours at a rate of 0.25 g/l BiNbO₄ turns liquid were capacity ≈ 99 %. After the 3^rd time of regeneration the BiNbO₄ also able to be used by evidence of 97.20 % of removing methyl orange.