Green synthesis of Co3O4-NPs by a HPCM method using Azadirachta indica leaf extract is reported. HRTEM shows hollow sphere like NPs with polycrystalline nature and it is used in catalytic applications.

John Kennedy L

Physics

School of Advanced Sciences

Chennai Campus

Sivachidambaram M

Vijaya J.J

Kaviyarasu K

Al-Lohedan H.A

Jothi Ramalingam R.

Fulltext

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

RSC Advances

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

Journal of the Taiwan Institute of Chemical Engineers

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

Strontium doped lanthanum cuprate perovskite-type nanostructures were synthesized by facile microwave assisted combustion method. The structural, optical, morphological, and magnetic properties were studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), photoluminescence (PL) and vibrating sample magnetometer (VSM) techniques.The XRD patterns of pure La2CuO4 (LC) and La1.9Sr0.1CuO4 confirmed the formation of perovskite structure without impurities. However with the increase in Sr2+ content from (x = 0.2–0.5), phase transformation from orthorhombic to tetragonal structure, occurred. The average crystallite size of orthorhombic and tetragonal phases were in the range 39.6–47.4 nm and 22.3–88.0 nm, respectively. The presence of tensile strain in Sr2+ doped LC (LSC) was determined from Williamson–Hall (W–H) analysis. The appearance of FT-IR bands at around 688 and 521 cm-1 were correlated to the La-O and Cu-O stretching modes of orthorhombic La2CuO4 phase. The direct band gap estimated using Kubelka–Munk (K–M) method increased with increasing Sr2+ content (1.88–2.03 eV), due to quantum confinement. For LC and LSC, PL spectra showed emission bands in UV and visible regions, due to the defect centers acting as trap levels. The LSC system showed the formation of nanosized crystallized grains with pores and pore-walls due to fused grains. Magnetization–Field (M−H) hysteresis curves revealed the appearance of ferro-/para- magnetic behavior at room temperature. © 2018 Elsevier B.V.

Journal of Magnetism and Magnetic Materials

Facile microwave assisted combustion synthesis, structural, optical and magnetic properties of La2−Sr CuO4 (0 ≤ x ≤ 0.5) perovskite nanostructures

In the present study, we report the green synthesis of NiO nanoparticles using Aegle marmelos as a fuel and this method is ecofriendly and cost effective. The plant Aegle marmelos is used in the field of pharmaceuticals to cure diseases like chronic diarrhea, peptic ulcers and dysentery in India for nearly 5 centuries. The as-prepared nanoparticles were confirmed as pure face centered cubic phase and single crystalline in nature by XRD. The formation of agglomerated spherical nanoparticles was shown by HR-SEM and HR-TEM images. The particle size calculated from HR-SEM was in the range 8–10 nm and it matches with the average crystallite size calculated from the XRD pattern. NiO shows intense emission peaks at 363 and 412 nm in its PL spectra. The band gap of 3.5 eV is observed from DRS studies and the formation of pure Ni–O is confirmed by FT-IR spectra. The as-prepared NiO nanoparticles show super paramagnetic behavior, when magnetization studies are carried out. It is then evaluated for cytotoxic activity towards A549 cell culture, antibacterial activity and photocatalytic degradation (PCD) of 4‑chlorophenol (4‑CP), which is known as the endocrine disrupting chemical (EDC). From the results, it is found that the cell viability of A549 cells was effectively reduced and it showed better antibacterial activity towards gram positive bacterial strains. It is also proved to be an efficient and stable photocatalyst towards the degradation of 4‑CP. © 2018 Elsevier B.V.

Journal of Photochemistry and Photobiology B: Biology

Green synthesis of NiO nanoparticles using Aegle marmelos leaf extract for the evaluation of in-vitro cytotoxicity, antibacterial and photocatalytic properties

A novel synthesis protocol for Co3O4 nanocatalysts and their catalytic applications

The present work describes the successful synthesize of spinel magnetic ferrite Mn1-xNixFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 &amp; 0.5) nanoparticles via a simple microwave combustion method which was then evaluated for its photocatalytic activity in the degradation of indigo carmine (IC) synthetic dye, a major water pollutant. Our results reveal that the synthesized of Ni2+ doped MnFe2O4 nanoparticles possess well-crystalline pure cubic spinel phase, exhibit excellent optical and magnetic properties. Further, the photocatalytic performance of the synthesized nanoparticles at different concentration ratios of Ni2+ ions was monitored by photocatalytic degradation of indigo carmine synthetic dye under UV (λ = 365 nm) light irradiation. In order to get maximum photocatalytic degradation (PCD) efficiency, we have optimized various parameters, which include catalyst dosage, initial dye concentration, pH and Ni2+ dopant content. It was found that the reaction was facilitated with optimum catalyst dose of 50 mg/100 mL, high dye concentrations of 150 mg/L and acidic pH and among all the synthesized samples, Mn0·5Ni0.5Fe2O4 exhibit superior performance of photocatalytic activity on the degradation of indigo carmine synthetic dye. These results highlighted the potential use of effective, low-cost and easily available photocatalysts for the promotion of wastewater treatment and environmental remediation. In addition, the antibacterial activity of spinel magnetic Mn1–xNixFe2O4 nanoparticles against two Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli) was also examined. Our antibacterial activity results are comparable with the results obtained using the antibiotic, streptomycin. © 2016 Elsevier B.V.

Studies on the efficient dual performance of Mn1–xNixFe2O4 spinel nanoparticles in photodegradation and antibacterial activity

Nickel oxide nanoparticles supported activated carbon (NSAC) photocatalyst was successfully prepared using a cost-effective microwave irradiation method. The earned UV light-sensitive NSAC composites were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, High-resolution scanning electron microscope with energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller surface area analyzer. Optical properties of NSAC composites were investigated using UV–Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy, which exposed prolonged light absorption in UV light region and hold better charge separation capability, respectively, as compared to pure NiO. The photocatalytic activity was tested by the degradation of textile dye waste water (TDW) under UV light irradiation. Chemical oxygen demand of TDW was calibrated before and after the photocatalysis experiment under UV light to evaluate the mineralization of wastewater. The results demonstrated that NSAC composites showed imposing photocatalytic enrichment over pure NiO. The coordinated blending of the oxygen vacant sites, structural defects of NiO along with electron transmission capacity, and presence of surface oxygen on AC has led to the lasting light absorption, delayed charge recombination, and sustenance, which favor the enrichment of the photocatalytic activity of NSAC. © 2014 Balaban Desalination Publications. All rights reserved.

Desalination and Water Treatment

Synergy effect in the photocatalytic degradation of textile dyeing waste water by using microwave combustion synthesized nickel oxide supported activated carbon

Advanced Powder Technology

Corrigendum to ‘Green and eco-friendly synthesis of cobalt-oxide nanoparticle: Characterization and photo-catalytic activity’ [Adv. Powder Technol. 28 (2017) 2035–2043]

Journal	Data powered by TypesetRSC Advances
Publisher	Data powered by TypesetRoyal Society of Chemistry (RSC)
ISSN	20462069
Open Access	Yes