Effect of annealing temperature on the synthesis and photocatalytic properties of Bi0.65K0.2Ba0.15FeO3 perovskite-like nanoparticle synthesized by sol-gel method

Abstract

Background: BiFeO 3 shows promising applications in photocatalytic degradation, purification process, and in clean energy generation. The various fascinating properties of bismuth ferrite nanoparticles can be improved by doping the material at either of the A or B sites to give it extra photocatalytic advantage toward decreasing the energy bandgap and other photophysical properties of the material. Results: In this research, pure Bi 0.65 K 0.2 Ba 0.15 FeO 3 perovskite material was synthesized using the sol-gel method via citric acid route in the presence of sodium dodecyl sulfate (SDS). The powdered nanoparticles were annealed at different annealing temperatures of 600, 700, and 800°C each for 4 h in a muffle furnace and coded K2BFO 600, K2BFO 700, and K2BFO 800 corresponding to the annealing temperature of each portion. The powder nanoparticles were characterized using powdered X-ray diffraction (PXRD) to determine the crystallite structure. The samples displayed similar peak patterns with increase in intensity as the annealing temperature is increased indicating an increase in crystallinity. The impurity peaks in K2BFO 800, however, show that the sample may contain a secondary phase. Scanning electron microscopy (SEM) was used to determine the morphology, and UV-Vis spectroscopy indicated that all the powders were photoactive within the visible region of the electromagnetic spectrum. ATR-FTIR spectra of the samples were collected to study the formation and phase purity of the B-site in the perovskite structures. The photocatalytic performance of the powder was tested on methylene blue dye under visible light irradiation for the degradation studies. All powders showed photocatalytic ability after 2 h of irradiation with the powder annealed at 800°C being better. The photocatalytic activities of the powders showed improvement on addition of 2 drops of 1 M H 2 O 2 (80% degradation for K2BFO 800). The bandgap energy of K2BFO 800, 700, and 600 was estimated at approximately 2.00, 2.12, and 2.18 eV, respectively, using Tauc's equation. The improved activity is as a result of photoabsorption of visible light by the doped powders causing generation of electrons and holes. The kinetic studies were carried out and the mechanisms of the photocatalytic reaction proposed. Conclusion:The effect of annealing temperature on synthesis of the material shows enhanced photoactivity in the presence of hydrogen peroxide leading to improved performance for the degradation of MB, and the catalyst can be said to be a good candidate for the treatment of waste materials.

Synthesis of Ti4+ doped Ca-BiFO3 for the enhanced photodegradation of moxifloxacin

“…25 Herein, the amount of photocatalysts was optimized at 1.5 g L −1 for the maximum degradation of MXF after 60 min of treatment. 26…”

Bismuth ferrite (BiFeO3) perovskite-based advanced nanomaterials with state-of-the-art photocatalytic performance in water clean-up

“…It increases the number of electrons in the conduction band and eventually slows down the recombination process, hence serving a better photocatalytic activity. 24,180…”

“…It increases the number of electrons in the conduction band and eventually slows down the recombination process, hence serving a better photocatalytic activity. 24,180 In a recent study by a group of researchers, La and Mncodoped nanohybrid of bismuth ferrite with varying doping concentrations were prepared using a double solvent sol-gel method. Further, these were embedded into transition metal carbide sheets (MXene-Ti 3 C 2 ) to prepare a nanocomposite and their resulting photocatalytic activity was observed against a sample of Congo red dye as shown in Fig.…”

Photocatalytic activity and doping effects of BiFeO3 nanoparticles in model organic dyes

“…The sol is then dried to give gel and the gel is pre-calcined to give pure nanopowders. This technique has been used widely for the preparation of pure BFO and BFO related materials (Kuang et al, 2015;Abdulkadir et al, 2016;Haruna et al, 2018Haruna et al, , 2019Haruna et al, , 2020.…”