Herein we reported the photocatalytic and antibacterial activity of CoFe2O4, CoFe1.9Bi0.1O4 and Cu0.5Co0.5Fe1.9Bi0.1O4 nanoparticles obtained by solution combustion technique using glycine as a fuel. The obtained nanoparticles were analyzed by various techniques such as powder XRD, FTIR, UV-DRS and SEM-EDAX. The band gap value of CoFe2O4 nanoparticle is decreases gradually from 1.46 to 1.00 eV (CoFe1.9Bi0.1O4) and 0.85 eV (Cu0.5Co0.5Fe1.9Bi0.1O4) due to the doping of copper and bismuth. The photocatalytic activity of synthesized nanoparticles was evaluated for the degradation of congo red dye. 89 and 87% removal efficiency of congo red dye was achieved in 90 min under different light (UV and visible light) illumination utilizing 10 mg of Cu0.5Co0.5Fe1.9Bi0.1O4 catalyst. Antibacterial activity of the compounds was tested against two organisms Staphylococcus aureus and Escherichia coli by well diffusion method. Co-doping of copper and bismuth improved the antibacterial activity against the organisms S. aureus (29 mm) and E. coli (34 mm) when compared to cobalt ferrite. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Sumathi S

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Kirankumar V.S

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.

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VIT University

Journal of Materials Science: Materials in Electronics

In the current investigation, a new series of Ce doped gahnites of the formula ZnAl2-xCexO4 (x = 0–0.04), Fe doped gahnites of the formula ZnAl2-yFeyO4 (y = 0–0.5) and Ce and Fe co-doped gahnites of the formula ZnAl2-x-yCexFeyO4 (x = 0–0.04; y = 0–0.5) with high near infrared (NIR) reflectance were fabricated to mitigate the heat island effect. All the designed pigments were characterized by powder X-ray diffraction (PXRD), Fourier transformed infra red spectroscopy (FT-IR), Ultraviolet-Diffuse reflectance spectroscopy (UV-DRS). Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscopy (TEM) and CIE-L*a*b* colour values. Band gap of the white gahnite of the formula ZnAl2O4 (Eg = 3.8 eV) shifted to 2.70 eV and 2.15 eV for the pigments ZnAl1.96Ce0.04O4 and ZnAl1.5Fe0.5O4 respectively. Ce doped gahnites broadened the absorption centre from 250 nm to 350 nm in the UV spectrum and resulted in yellow colour. Whereas Fe doping introduced additional electronic transition between 440 nm and 490 nm and exhibited reddish yellow colour. NIR reflectance of ZnAl1.96Ce0.04O4, ZnAl1.5Fe0.5O4 and ZnAl1.78Fe0.2Ce0.02O4 was found to be 86%, 65%, 80% respectively between 700 and 2500 nm regions. Good thermal and chemical stability along with high NIR reflectance made the prepared pigments as a potential candidate to design cool roofing materials. © 2019 Elsevier B.V.

Journal of Alloys and Compounds

Ce and Fe doped gahnite: Cost effective solar reflective pigment for cool coating applications

In the current research, ZnFe2O4, Zn0.50Cu0.50Fe2O4, ZnFe1.90Bi0.10O4, ZnFe1.95Ce0.05O4, Zn0.50Cu0.50Fe1.90Bi0.10O4 and Zn0.50Cu0.50Fe1.95Ce0.05O4 magnetic nanoparticles were synthesized to remove the BPA (bisphenol A) from contaminated water through photocatalytic performance. The synthesized nanoparticles were characterized by powder XRD, UV-DRS, FT-IR, SEM-EDAX, VSM and XPS. From the XRD results it was observed that the particle size ranged from 38.26 to 30.18 nm. UV-DRS showed the band gap value ranging from 1.94 to 1.04 eV for the fabricated magnetic nanoparticles. Under 250 W UV-light irradiation, degradation of BPA using Zn0.50Cu0.50Fe1.90Bi0.10O4 and Zn0.50Cu0.50Fe1.95Ce0.05O4 nanoparticles were 90.09 and 91.25% in 180 min with the rate constant of (k) 0.02250 and 0.02365 min−1, respectively. The reactive species responsible for photocatalytic degradation were hydroxy radicals and superoxide radicals. 87.89% and 88.91% of degradation was observed after three cycles using Zn0.50Cu0.50Fe1.90Bi0.10O4 and Zn0.50Cu0.50Fe1.95Ce0.05O4 nanoparticles. The outcomes indicated that Zn0.50Cu0.50Fe1.90Bi0.10O4 and Zn0.50Cu0.50Fe1.95Ce0.05O4 nanoparticles show good stability for BPA degradation. © 2019 Taiwan Institute of Chemical Engineers

Journal of the Taiwan Institute of Chemical Engineers

Effect of co-doping of bismuth, copper and cerium in zinc ferrite on the photocatalytic degradation of bisphenol A

A rapid synthetic technique is investigated for magnetic nanoparticles (Co1−yCuyFe2−xCexO4 (x = 0, y = 0), (x = 0.05, y = 0), (x = 0, y = 0.5), and (x = 0.05, y = 0.5)). The structure, morphology, optical and magnetic performance of prepared nanoparticles are analyzed by powder XRD, XPS, FT-IR, SEM-EDAX, TEM, DRS, and VSM. The photocatalytic activity of the synthesized nanoparticles for the removal of the Congo red (CR) dye and bisphenol A (BPA) from aqueous solution is examined by UV–visible spectrometer. Research indicates that the co-doping of Cu2+ and Ce3+ showed marked effect on the structural, optical, magnetic, and photocatalytic properties of the CoFe2O4 nanoparticles. DRS showed that the Co0.5Cu0.5Fe1.95Ce0.05O4 nanoparticles have lower band gap energy (0.78 eV) than other synthesized compounds. High removal percentage of CR and BPA (99.09% and 99.33%) was observed within 30 min and 180 min under visible and UV–light illumination respectively using Co0.5Cu0.5Fe1.95Ce0.05O4. The corresponding photocatalytic degradation kinetics and mechanism are analyzed. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Environmental Science and Pollution Research

Copper and cerium co-doped cobalt ferrite nanoparticles: structural, morphological, optical, magnetic, and photocatalytic properties

Cerium-doped copper aluminate (CuAl2- xCexO4, x = 0, 0.01, 0.03, and 0.05) photo-catalysts were synthesized by combustion route with an aim to improve the photocatalytic activity of copper aluminate under visible-light. The synthesized compounds were analyzed by standard analytical instruments such as powder XRD, FT-IR, UV-DRS, SEM-EDAX, and HR-TEM. XRD results explained that rising cerium ion concentration from 0 to 0.03, increase the lattice parameter and decreases the average crystalline size. The band gap energy of copper aluminate (1.81 eV) was reduced to 1.43 eV by introducing the cerium ion. The photodegradation performance of the synthesized compounds was recorded by studying the degradation of organic pollutants such as Rhodamine B and Methylene blue dyes under visible light. Cerium doped copper aluminate (x = 0.03) nanoparticles shows 98% degradation of RhB and 96% degradation of MB after 180 and 90 min than the doped (x = 0.01, 0.05) and undoped copper aluminate (x = 0) nanoparticles, respectively. The reactive species h+ and ·O2 ‒ plays the most important role in the photocatalytic degradation. The photodegradation of colorless pollutant Bisphenol A was carried out under UV-light. Among the series of synthesized compounds, CuAl1.97Ce0.03O4 nanoparticles were found to be the more active photo-catalyst for the degradation of Rhodamine B and Methylene blue. © 2018 Taiwan Institute of Chemical Engineers

Photocatalytic performance of cerium doped copper aluminate nanoparticles under visible light irradiation

Cobalt ferrite, copper and bismuth co-substituted cobalt ferrite nanoparticles are prepared by solution combustion method. The synthesized compounds are authenticated by powder X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy-Energy dispersive X-ray analyser and Vibrating sample magnetometer. Particle size, lattice parameter, saturation magnetization and coercivity as a function of bismuth and copper substitution in cobalt ferrite nano particles are studied. Lattice parameter and dielectric constant are increased due to the substitution of bismuth in cobalt ferrite. Catalytic activity of the synthesized compounds are tested for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The conversion of nitrophenol to amino phenol is achieved in seconds using the substituted cobalt ferrite compounds. © 2016, Springer Science+Business Media New York.

Structural, magnetic, electrical and catalytic activity of copper and bismuth co-substituted cobalt ferrite nanoparticles

In this study, cobalt ferrite and bismuth substituted cobalt ferrite (CoFe2−xBixO4 x=0, 0.1) nanoparticles were synthesized by two different methods viz combustion and co-precipitation. The nanoparticles were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), scanning electron microscopy-energy dispersive X-ray analyzer (SEM-EDX) and vibrating sample magnetometer (VSM). The results of powder XRD pattern showed an increase in lattice parameter and decrease in particle size of cobalt ferrite by the substitution of bismuth. Catalytic activity of cobalt ferrite and bismuth substituted cobalt ferrite nanoparticles synthesized by two different methods were compared for the reduction of 4-nitrophenol to 4-aminophenol using NaBH4 as a reducing agent. © 2016 Elsevier B.V.

Journal of Magnetism and Magnetic Materials

Comparison of catalytic activity of bismuth substituted cobalt ferrite nanoparticles synthesized by combustion and co-precipitation method

Nanostructured Co1-xZnxFe2O4 (0≤x≤0.5) catalyst synthesized by the microwave combustion method was employed for the photocatalytic degradation of rhodamine B (RhB) under visible light. Doping of Zn2+ ions in the cobalt ferrite matrices were confirmed by the diffraction peak-shift towards lower angles. The Williamson-Hall method was used to calculate the crystallite size considering the strain components. The conduction band (CB) and valence band (VB) edges of all the samples were calculated using optical studies. Photoluminescence analysis performed at an excitation wavelength of 330 nm disclosed the rate of recombination of electron-hole pairs and the defects present. Photocatalytic degradation of RhB with pure cobalt ferrite system was performed at pH 2.0 by varying the time, initial concentration and addition of hydrogen peroxide to behave like a Fenton like process. However the effective photodegradation of all zinc doped cobalt ferrite were done at optimal RhB concentration of 6 mg/l at identical operational conditions. Among all the samples Co0.6Zn0.4Fe2O4 exhibited an enhanced degradation efficiency of 99.9% at visible light exposure time of 210 min. The degradation pathway followed first order rate rather than the second order rate kinetics. Based on the values of CB and VB edges in the Co0.6Zn0.4Fe2O4 system, possible routes for the degradation of RhB are suggested. © 2016 Elsevier Ltd and Techna Group S.r.l.

Journal	Data powered by TypesetJournal of Materials Science: Materials in Electronics
Publisher	Data powered by TypesetSpringer Science and Business Media LLC
ISSN	0957-4522
Open Access	0