Sodium Dodecyl Benzene Sulfonate-assisted Synthesis and Natural Sunlight Photocatalytic Activity of La Bismuthate Nanorods

Abstract

Background: Removal of the organic pollutants using the photo-catalysts by the photocatalytic treatment process under natural sunlight irradiation has attracted great attention owing to the complete destruction of the organic pollutants. The La bismuthate nanorods possess good photocatalytic performance for the removal of the methylene orange (MO) under the sunlight irradiation. Objective: The aim is to synthesize La bismuthate nanorods by hydrothermal method and research the photocatalytic performance of the La bismuthate nanorods for MO degradation under sunlight irradiation. Methods: La bismuthate nanorods have been synthesized by a simple sodium dodecyl benzene sulfonate (SDBS)-assisted hydrothermal method using sodium bismuthate and La acetate as the starting materials. The obtained La bismuthate products were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy and solid UV-vis diffuse reflectance spectrum. Results: With different SDBS concentration, hydrothermal temperature and reaction time, different morphologies of the La bismuthate products were obtained. XRD analysis shows that the La bismuthate nanorods obtained from 180°C for 24 h with 5wt.% SDBS are composed of orthorhombic La1.08Bi0.92O3.03 phase. Electron microscopy observations show that the La bismuthate nanorods with flat tips have the length of longer than 10 μm and diameter of about 20-100 nm, respectively. The morphology and structure of the products are closely related to the SDBS concentration, hydrothermal temperature and reaction time. Solid UV-vis diffuse reflectance spectrum shows that the band gap of the La bismuthate nanorods is 2.37 eV. The La bismuthate nanorods show good photocatalytic performance for the degradation of MO under the sunlight irradiation. MO solution with the concentration of 10 mg.L-1 can be totally removed by 10 mg La bismuthate nanorods in 10 mL MO aqueous solution under sunlight irradiation for 6 h. Conclusion: The photocatalytic performance for the removal of MO is dependent on the sunlight irradiation time and dosage of the La bismuthate nanorods. The La bismuthate nanorods exhibit great potential for the removal of organic pollutants.