Highly efficient and selective heterogeneous catalytic reduction of 2-nitroaniline by cerium oxide nanocatalyst under microwave irradiation

Efficient nanocatalyst with incredible performance is highly demanding in a heterogeneous catalysis system. Herein, we report the facile fabrication of uniform and highly stable Cerium Oxide nanoparticles (CeO₂ NPs), through chemical precipitation method using sodium hydroxide as reducing agent. The synthesized material is characterized through highly sophisticated techniques including UV-Visible, FT-IR, SEM, AFM, XRD, and Zeta Sizer- Potential to check the particle formation, surface morphology, topography, crystalline nature, size, and surface potential. The heterogeneous catalytic performance of CeO₂ NPs has been accomplished for the reduction of 2-nitroaniline from the aqueous media. The CeO₂ nanocatalyst displayed excellent reusability, while the reduction in several repetitive catalytic cycles against 2-nitroaniline under optimized conditions. The CeO₂ nanocatalyst shows 99.12% efficiency within 60s reaction time under a greener source of microwave radiation.

Importance and Analytical Perspective of Green Synthetic Strategies of Copper, Zinc, and Titanium Oxide Nanoparticles and their Applications in Pathogens and Environmental Remediation

Background:

Nanotechnology is a promising field of science which deals with the production and utilization of material under nanoscale dimensions. The nanoscale regime provides exceptional applications in various fields of science due to its large surface to volume ratio and many valuable properties. Hence, the production and use of nanomaterials are the prominent areas of modern research. Amongst the nanomaterials, metal oxide NPs have gained much attention due to their vast number of applications in different areas, including electrochemical applications, dye degradation, catalysis, and are known to be the exceptional entities in the battle against different pathogens. The metal oxides are viably synthesized through chemical methods that require the use of many noxious chemicals. Henceforth, it is the demand of the modern world to carry out research on the synthesis of metal oxide nanomaterials through eco-friendly, greener, and non-toxic routes. Thus, various green methods are employed to engineer the metal oxide NPs by using different greener, cheaper, and eco-friendly sources, employing the use of plant extracts, bacteria, fungi and other biological bodies. The present review covered the green synthesis of CuO, ZnO, TiO2 NPs and their applicability towards different pathogens and environmental remediation reported from the year 2015 to date.

Objective:

The exceptional catalytic properties, environmental, and anti-microbial applications of metal oxide, especially CuO, ZnO, TiO2, are the main highlights of this review articles. The most cost-effective and greener routes for the synthesis of CuO, ZnO, TiO2, are discussed in the present review. To date, various green synthetic methods for the preparation of mentioned nanoparticles and their applicability towards different pathogens and degradation of different hazardous dyes with some electrochemical applications has been thoroughly covered in this review.

Conclusion:

The biosynthesis of metal oxide NPs using greener and eco-friendly approaches have been the attentive area in the last decade. Green synthesis requires chemical-free active components from biological sources, which act as both the reducing and stabilizing agent for the size and shapecontrolled production of NPs. The future vision of bacterial, fungal, and plant-mediated production of NPs includes the postponement of laboratory-based work to a large industrial scale, exposition of different phytochemicals involved in the biosynthesis of NPs using bioinformatics techniques and stemming the real mechanism involved in preventing the growth of pathogenic bacteria, fungi, and algae. The plant-mediated NPs can have diverse applications in the arena of pharmaceutical, food, and cosmetic industries, and thus, became a vital area of modern research.

Fabrication of nickel-tagged magnetic imprinted polymeric network for the selective extraction of Ni(II) from the real aqueous samples

A new nickel ion, magnetic imprinted polymer was fabricated through the precipitation polymerization process, using amine-functionalized silica-capped iron oxide particles as a core material, and 4-vinyl pyridine as complexing agent methacrylic acid as functional monomer. The resulted magnetic adsorbent was employed to eliminate toxic Ni²⁺ ions from industrial wastewater. The different parameters were optimized, such as pH, shaking speed, and adsorbent dose, to obtain the maximum adsorption capacity. The synthesized material showed high selectivity coefficient for Ni⁺² ions in the presence of other competitive ions and followed pseudo-second-order kinetics and Langmuir isotherm. A good adsorption capacity of 158.73 mg g^-1 was obtained at optimized pH 6 in the concentration of 5 mg L^-1 nickel ions aqueous solution. The limit of detection, quantification, and the percent relative standard deviation was found to be 0.58, 1.93, and 3.4%. This proves the excellent performance of prepared magnetic Ni(II) ion-imprinted polymer for selective detoxification of Ni²⁺ ions from real aqueous samples. Due to tunable magnetic properties, the prepared MMIPs are highly selective and sensitive and highly porous in nature; due to excellent magnetic properties, there is no need for centrifugation. Just use external magnetic field, it has good reusability. Showing preparation of Ni (II) imprinted magnetic polymer.

Fabrication of Pt-Pd@ITO grown heterogeneous nanocatalyst as efficient remediator for toxic methyl parathion in aqueous media

In this study, nano-sized ITO supported Pt-Pd bimetallic catalyst was synthesized for the degradation of methyl parathion pesticide, a common extremely toxic contaminant in aqueous solution. On the characterization with different techniques, a beautiful scenario of honeycomb architecture composed of ultra-small nanoneedles or fine hairs was found. Average size of nanocatalyst also confirmed which was in the range of 3-5 nm. High percent degradation (94%) was obtained in 30 s using 1.5 × 10^- 1 mg of synthesized nanocatalyst, 0.5 mM NaBH₄, and 110 W microwave radiations power. Recyclability of nanocatalyst was efficient till 4th cycle observed during study of reusability. The supported Pt-Pd bimetallic nanocatalyst on ITO displayed many advantages over conventional methods for degradation of methyl parathion pesticide, such as high percent degradation, short reaction time, small amount of nanocatalyst, and multitime reusability. Graphical abstract Schematic illustration of reaction for degradation of methyl parathion.

Fabrication of chromium-imprinted polymer: a real magneto-selective sorbent for the removal of Cr(vi) ions in real water samples

Graphical representation (a and b) show the procedure for the synthesis of Cr(vi) ion-imprinted magnetic polymer.

1,4-Methano-11a-methyl-4,4a,11,11a-tetrahydro-1H-benzo[b]fluoren-11-one

The title compound, C(19)H(16)O, crystallizes with two molecules of opposite chirality in the asymmetric unit. In both molecules, the naphthalene and cyclopentanone moieties are individually planar. The two cyclopentane rings adopt envelope conformations, while the cyclohexane ring adopts a boat conformation.