چكيده به لاتين
Abstract:
Scientists have been focus on environmental issues due to global environmental pollution and lack of clean energy. One of the ways to overcome with environmental pollution is to decompose toxic and harmful molecules and convert them into non-toxic substances by photocatalytic processes. Bismuth ferrite has been widely considered because of its small bandgap (2/2-2/8 eV) and excellent chemical stability during the photocatalytic process. In this study, bismuth ferrite nanoparticles were initially synthesized by using various organic fuels (glycine and CTAB) in various amounts (Փ =0.5, 0.75, 1 and 2) and their properties were investigated. Type of heating, namely conventional combustion, combustion with calcination (600 °C for 1 h) and microwave-combustion were investigated for the bismuth ferrite nanoparticles which are synthesized with glycine fuel. Finally, BFO/x% CFO nanocomposites with two different molar ratios x=10, 20 were synthesized by solution combustion method. Composites did not exhibit photocatalytic properties and exhibited adsorbing properties for removing organic contaminant like methylene blue. Infrared spectroscopy, thermal analysis (TGA/DTA), X-ray diffractometry, electron microscopy, vibrating sample magnetometry, nitrogen adsorption–desorption, diffuse reflectance spectroscopy techniques, UV-Visible absorption spectrometry, and photocatalytic and absorption test were used to investigate the properties of nanoparticles in different conditions. Also, by performing a photocatalytic study, the performance of bismuth ferrite powder was investigated in methylene blue degradation under visible light irridation. In the samples synthesized with CTAB, the particle size decreases from (0/5-0/7μm) to 120 nm with increasing Փ due to the decreasing adiabatic temperature. The bismuth ferrite synthesized with CTAB fuel at Փ =0.5, after 3 hours of radiation, destroyed 85% of methylene blue solution (15mg/L). Bismuth-ferrite/cobalt ferrite nanocomposites showed an absorption capacity approximately 16 mg/g after 40 minutes. Also, the magnetization of nanocomposite powders of BFO-10CFO and BFO-20CFO reached the values of 6.3 emu/g and 12.6 emu/g, respectively. Therefore, the composite of bismuth ferrite with cobalt ferrite not only increased its magnetic properties, but also significantly improved the methylene blue removal efficiency.
Keywords:
Bismuth ferrite, Photocatalytic Process, Solution Combustion Synthesis, Bismuth ferrite - Cobalt ferrite Nanocomposites
