Selective Photodegradation on Dual Dye System by Recoverable Nano SnO_2 Photocatalyst

摘要

A facile co-precipitation technique was developed to prepare SnO2 nanoparticles using stannous chloride dihydrate (SnCl(2)2H(2)O) and characterized. The photocatalytic efficiency of nano SnO2 was tested for degradation of Rhodamine B: C28H31ClN2O3+(nano SnO2/lambda=254nm)+reactive species ((O2-, center dot OH)-O-center dot, (OOH)-O-center dot) - H2O+CO2. In addition, mixture of Rhodamine B (RhB) and malachite green oxalate (MGO) were selected as the dual dye system (model pollutants) and their influencing factors such as concentration of mixtures (RhB+MGO), catalyst dosage, intensity of light source (254 and 365nm), pH were also studied. Blank experiment (without catalyst) and surface adsorption indicates that Rhodamine B degrades at relatively very slow rate with k=2.30x10(-3)min(-1) and k=2.4x10(-3)min(-1) respectively. However, nano SnO2 induces a large increment in degradation rate corresponding with k=4.0x10(-3)min(-1) (RhB=8.69x10(-6)M, catalyst 50mg/100mL, lambda=254nm) and mixed dyes k(RhB)=18.96x10(-3)min(-1) and k(MGO)=26.5x10(-3)min(-1) were obtained. Further, the reusability of the catalyst was sustained up to three cycles and verified with XRD pattern.