Enhanced visible light photocatalytic activity of magnetic cobalt doped BiFeO3

Abstract

Photocatalysis is drawing considerable research attention because of its extensive applications in the field of environmental remediation and renewable energy. In this work, synthesis and activity of magnetic BiFe1-xCoxO3 (x = 0, 0.025, 0.05, 0.075 & 0.10) photocatalysts under visible light irradiation is reported. The photocatalyst materials were synthesized using the Gel combustion method assisted by citric acid as fuel. The X-ray diffraction studies reported distorted rhombohedral structure with decreasing crystallite size and increasing dopant concentrations. The X-ray Photoelectron spectroscopy studies confirmed that Bi, Fe and Co are in 3+ states. The optical band gap showed a decrease in the bandgap, which might be due to the presence of oxygen vacancies in the system. The infra-red spectroscopic studies exhibited similar vibrating modes of BiFeO3. Morphological studies also show a decrease in crystallite size. An increase in magnetic property was observed for all samples, with the highest magnetic behaviour seen in the 5% cobalt doped BiFeO3. The influences of Co doping content on photocatalytic activity of BiFeO3 were investigated. The photocatalytic degradation of Acid Red-85 dye followed pseudo-first-order kinetics, with the greatest performance found in BiFe0.925Co0.075O3 with 93.79% degradation after 2 h of light exposure. Photoluminescence and photocurrent studies validate efficient charge separation for enhanced photocatalytic behaviour.