Solution combustion synthesis of Nano sized ferroelectric (1-x)KNbO3-x(BaNi1/2Nb1/2O3-δ): characterization, mechanism and photocatalytic properties

Abstract

The present paper reports the synthesis of (1-x)KNbO3-x(BaNb1/2Ni1/2O3- δ) (x = 0, 0.05, 0.1 and 0.15) [KBNNO] by solution combustion method using citric acid as the fuel. The effect of fuelto-oxidizer ratio (Фe) (0.6-1.0) in the combustion process and phase evolution has been studied. For the first time, we report that the phase purity can be achieved at room temperature by controlling the fuel to oxidizer ratio of the starting solution. X-ray diffraction and Raman spectroscopy clearly show the phase transition from orthorhombic to cubic phase with increase in doping concentration (x > 0.1). FESEM and TEM have been used to determine the morphology of the powder. UV-Vis absorption spectroscopy indicates that KBNNO have significant absorption in the visible range when compared with KNbO3 synthesized under same conditions. Photocatalytic activity evaluation displays an enhanced visible light photocatalytic activity of KBNNO in degrading rhodamine B in comparison with KNbO3.