Modern Nanotemplates Based on Graphene and Single Layer h-BN

ZnO/UV/H2O2 Based Advanced Oxidation of Disperse Red Dye

In view of promising efficiency of advanced oxidation process, ZnO/UV/H2O2 based advanced oxidation process (AOP) was employed for the degradation of Disperse Red-60 (DR-60) in aqueous medium. The process variables such as concentration of catalysts, reaction time, pH, dye initial concentration and H2O2 dose were evaluated for maximum degradation of dye. The maximum degradation of 97% was achieved at optimum conditions of H2O2 (0.9 mL/L), ZnO (0.6 g/L) at pH 9.0 in 60 min irradiation time. The analysis of treated dye solution revealed the complete degradation under the effect of ZnO/UV/H2O2 treatment. The water quality parameters were also studied of treated and un-treated dye solution and up to 79% COD and 60% BOD reductions were achieved when dye was treated with at optimum conditions. The dissolved oxygen increased up to 85.6% after UV/H2O2/ZnO treatment. The toxicity was also monitored using hemolytic and Ames tests and results revealed that toxicity (cytotoxicity and mutagenicity) was also reduced significantly. In view of promising efficiency of UV/H2O2/ZnO system, it could possibly be used for the treatment of wastewater containing toxic dyes.

Green Synthesis of Metal Nanoparticles and their Applications in Different Fields: A Review

Nanotechnology is an art for application and handling of materials at very small scales i.e. 1–100 nm. The materials at this scale exhibit significantly different properties compared to same materials at larger scales. There are so many physical and chemical methods for the synthesis of nanoscale materials but the most appropriate are the ones that synthesize materials using green chemistry eco-friendly techniques. Recently, the collaboration between nanotechnology and biology has opened up new horizons of nanobiotechnology that integrates the use of biological materials in a number of biochemical and biophysical processes. This approach has significantly boosted up nanoparticles (NPs) production without employing harsh and toxic conditions and chemicals. This review is aimed to provide an outline of latest developments in synthesis of NPs through biotic entities and their potential applications.

Hydrothermal Synthesis of Zinc Doped Nickel Ferrites: Evaluation of Structural, Magnetic and Dielectric Properties

Nickel–zinc ferrites are soft magnetic materials that have different technological applications due to their low magnetic coercivity, high electrical resistivity and low eddy current loss. The soft ferrites are the best for manufacturing core of power transformers, recording heads, data storage devices, telecommunication equipment, media devices, microwaves and electronic devices. In current investigation, a series of zinc doped nickel ferrites (ZnxNi1−xFe2O4, x = 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by hydrothermal method (at 220 °C, 16 h). The structural, magnetic and dielectric properties were measured. X-ray diffractometer and fourier transform infrared spectroscopy (FTIR) were used to analyze the structural properties and structure of zinc doped nickel ferrites was spinel. As the concentration of Zn was increased, the structural properties (lattice constant, density, dislocation density, radii of tetra and octahedral sites and oxygen positional parameters) were also changed. FTIR results showed the strongest absorption band at 500–600 cm−1, which indicate the intrinsic stretching vibration of Zn+2 ↔ O bond (Mtetra ↔ O) at tetrahedral site. Vibrating sample magnetometer (VSM) was used to measure magnetic properties and it was observed that the value of saturation magnetization increased with Zn concentration. The investigation of frequency dependent dielectric property was measured by Impedance Analyzer. Dielectric constant and tangent loss decreased at higher frequency, whereas AC conductivity increased with frequency.

Lead Remediation Using Smart Materials. A Review

The nanoparticles have been prepared and employed as excellent adsorbents for the sequestration of heavy metal ions and hazardous impurities from the aqueous media. The surface morphological, textural and structural properties of nanoparticles have been modified, which are capable and potentially useful for the remediation of metal ions. Several metals (oxides, doped, nanocomposites of Fe, Ti, Zn, SiO2, SiC, Mo, Co, Ni, Zr, Mn, Si, S, Al, Cu, Ce, graphene, CNTs) were reported an efficient adsorbents for the removal of lead (Pb) ions from aqueous media and polluted water. The present review focuses on different kinds of nanoparticles such as metal oxides, carbon based and host supported employed for removal of Pb ions under varying experimental conditions such as pH, temperature, contact time and concentrations. The preparation strategies, physicochemical properties and adsorption are also discussed. Based on studies, it was found that the smart materials are affective adsorbents for the purification of wastewater containing Pb ions and could possibly extended for the remediation of other heavy metal ions.

Synthesis and Characterization of ZnO Nanorods as an Adsorbent for Cr(VI) Sequestration

Zinc oxide (ZnO) nanorods were fabricated through hydrothermal route and employed for the adsorption of Cr(VI) ions from aqueous medium. Zinc nitrate hexahydrate (Zn(NO3)2.6H2O) was used as a zinc precursor and Triton-x 100 was used as a capping agent. As synthesized ZnO nanorods were characterized by UV-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-Ray spectroscopy (EDX) techniques. The adsorption affecting parameters were investigated for maximum adsorption of Cr(VI) onto ZnO nanorods. The adsorption kinetics, isotherms, and thermodynamics were applied for adsorption mechanism evaluation. Maximum adsorption of Cr(VI) ions (250 mg/g) was achieved using 0.055 g/L ZnO dose at pH 2.0 for the contact time of 30 min. Pseudo-second-order kinetic model and Langmuir isotherm explained well the Cr(VI) adsorption onto ZnO nanorods. The Cr(VI) adsorption onto ZnO was spontaneous and endothermic in nature. In view of promising adsorption efficiency, ZnO nanorods could possibly be used for Cr(VI) ions removal from wastewater and also extendable for the adsorption of other heavy metals ions.

The Nanostructuring of Atomically Flat Ru(0001) upon Oxidation and Reduction

The O/Ru(0001) system is widely studied due to its rich phase variety of various stoichiometry and atomic arrangements, including the formation of a RuO₂/Ru(0001) oxide layer. Apart from homogeneous ruthenium surfaces in certain oxidation states, also strongly heterogeneous surfaces can exist due to oxidation state's variation at the nanoscale. We report on a scanning tunneling microscopy (STM) study of the nanostructuring of the oxidized Ru(0001) surface as a result of its interaction with molecular oxygen at elevated temperatures and subsequent reduction of a resulting RuO₂ film by CO or HCl molecules from the gas phase in high-vacuum environment.