Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

The discharges of effluents from the Textile industries contain bleaching and dyeing chemicals which are very harmful to the environment. Thus, managing textile effluents to make zero discharge of the above chemicals using renewable energy is the need of the hour. Here we report photocatalytic degradation of Acid Red-85, textile dye in visible light by energy bandgap optimized magnetic nanoparticles. The BiFe1-xMnxO3 (x = 0, 0.025, 0.05, 0.075 &amp; 0.1) nanoparticles were synthesized by citrate gel auto-ignition method. The synthesized compounds show well-defined crystalline particles with decrease of crystallite size from 57 to 20 nm with increase of Mn2+ concentration. All samples show well-separated particle morphology with decrease of average particle size with increase of manganese concentration. Optical absorption studies reveal that the energy band-gap of sample decreases from 2.2 to 1.97 eV with increase of Mn ions in BiFeO3 lattice. The coercive field (Hc) and remnant magnetization (Mr) enhance up to 5% of manganese content and then reduces with further increase of dopant concentration due to hindrance of magnetic exchange in Mn-O-Fe network. Manganese doping helps in increasing the degradation efficiency of BiFeO3 nanoparticles and the rate constant (K) increases from 2.6 × 10−2 to 6.84 × 10−2 min−1respectively. It is attributed to long charge separation time in doped samples which is confirmed by photoluminescence spectrum. Mn-doped BiFeO3 has an edge over the widely studied TiO2 and ZnO because of its absorbance in visible light spectrum and its ability to be magnetically removed after treatment. © 2019, © 2019 Taylor &amp; Francis Group, LLC.

Physics

School of Advanced Sciences

Chennai Campus

Mechanical

School of Mechanical Engineering

International Journal of Green Energy

Visible light photocatalytic activity of Mn-doped BiFeO3 nanoparticles

Visible light driven photocatalytic property of nickel doped BiFeO3 nanoparticles were explored from the degradation of Acid red-85 dye. Fuel (citric acid) assisted auto-combustion method was adopted for the synthesis of BiFe(1-x)NixO3 (x = 0.25, 0.5, 0.75 and 0.10) nanoparticles. The synthesized particles were characterized by x-ray diffraction, from which reduction in crystallite size has been observed from 57 nm to 28 nm. Lattice parameters also have been calculated for the same which shows an increase in lattice parameters confirming the presence of nickel in the BiFeO3 lattice. Morphological studies were carried out using high resolution scanning electron microscopy on undoped and 10% nickel doped BiFeO3 samples which show a decrease in particle size in the doped sample compared to the bare BiFeO3 similar results have been observed in Transmission Electron Microscopy images. Reduction in the optical band gap from 2.2 eV to 2.02 eV of BiFeO3 compared to 10% Nickel doped bismuth ferrite is observed. Vibrating sample magnetometer studies performed at room temperature indicates that addition of nickel increases both remnant and saturation magnetization to the bismuth ferrite sample thus helping in the removal of photocatalyst after treatment. Photocatalytic study on the Acid red-85 dye by visible light irradiation showed the complete degradation of dye in 40 min. The 10% Nickel doped BiFeO3 showed the best photocatalytic activity. The enhancement in the photocatalytic activity of the doped BiFeO3 is because of efficient charge separation which has been confirmed by photoluminescence studies. © 2019 IOP Publishing Ltd.

Materials Research Express

Photocatalytic degradation of acid red-85 dye by nickel substituted bismuth ferrite nanoparticles

Different effluents from textile industries which are dumped into the water bodies have been a major concern of the modern world. The uncontrolled discharge of the synthetic textile dyes in water bodies especially have led to serious environmental problems and health hazards. Among the different existing approaches to treat water, photocatalysis is an attractive approach as it uses the inexhaustible and clean solar energy. Considering its ability to absorb in the visible light of solar spectrum, its multiferroic property and its crystal structure, researchers feel BiFeO3 can provide a breakthrough in the treatment of water. In this article, a thorough review is presented on the various attempts done so far on degradation of different synthetic textile dyes solution using BiFeO3 nanostructures. © 2017 Elsevier B.V.

Environmental Nanotechnology, Monitoring & Management

A review on the visible light active BiFeO 3 nanostructures as suitable photocatalyst in the degradation of different textile dyes

Multiferroic materials, which show simultaneous ferroelectric and magnetic ordering, exhibit unusual physical properties - and in turn promise new device applications - as a result of the coupling between their dual order parameters. BiFeO3 is currently considered the most promising candidate material for device applications of room temperature multiferroics. However, its G-type antiferromagnetic behavior and high Néel temperature restrict the use of this material in potential applications. We report the synthesis and characterization of a novel Bi2FeNiO6 material for the first time using a citric acid assisted gel combustion technique. Magnetization studies reveal that it exhibits ferrimagnetism with Néel temperature around 500 K. Differential scanning calorimetry study also reveals a sharp phase transition at 500 K. These materials also exhibit good ferroelectric behavior with square type hysteresis with a remanent polarization (Pr) of 1.28 μC cm-2, saturation polarization (Ps) of 18 μC cm-2 and coercive fields 20 kV and -40 kV respectively. The results are convincing to make a big step towards developing devices that run on spin. © 2013 Carl Hanser Verlag, Munich, Germany.