Auto-combustion preparation and characterization of CoAl_2O_4 nanoparticles with different morphologies and its photocatalyst application

摘要

Nanocrystalline cobalt aluminate (CoAl_2O_4 ) was prepared by auto-combustion method using aluminum nitrate and cobalt nitrate. Besides, amino acids such as glycine, alanine, and asparagine were used to investigate their effects on the morphology and particle size of CoAl_2O_4 nanoparticles. Amino acids play role as capping agent, reducing agent, and fuel in the synthesis CoAl_2O_4 nanoparticles. The as-obtained CoAl_2O_4 nanoparticles were analyzed by UV-vis diffuse reflectance spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray microanalysis, and X-ray diffraction. According to the vibrating sample magnetometer (VSM) result, CoAl_2O_4 nanoparticles indicated a paramagnetic behavior at room temperature. Furthermore, the photo-catalysis results reveal that the maximum decolorization of 76 % for methyl orange occurred with CoAl_2O_4 nanoparticles in 70 min under ultraviolet (UV) light irradiation.