Tuning magnetic, electronic, and optical properties of Mn-doped NiCr2O4 via microwave method

The main aim of the paper to the synthesis of Mn (x)-doped NiCr2O4 nanoparticles by varying Mn content (x = 0.00%, 0.01%, 0.02%, and 0.03%) by microwave method for correlating the effect of NiCr2O4 on structural, optical, and magnetic properties of the materials. Understanding the optical, magnetic, and structural properties of huge reservoir factors has essential applications in various aspects of materials science. Our study is to relate the reduction of grain size of Mn content in NiCr2O4 host material. The XRD results revealed that there was an apparent decrease in the characteristic peaks of Mn in the MnNiCr2O4 nanostructure. Particularly, the peak position of (220) and (311) planes was decreased. This decrease in peak position is attributed to the creation of defects or disorders due to the Mn ions in the chromite lattice structure. This inter-site Mn cation migration is responsible for the breaking of long-range cation order and the introduction of defects at both the T-site and O-sublattices site simultaneously

Chemical activation and magnetization of onion waste derived carbon for arsenic removal

Arsenic is a known human carcinogen and its contamination of drinking water has been a global challenge. In this study, magnetic activated carbon (MAC) as an efficient adsorbent material was synthesized by hydrothermal method. Three adsorbent materials MCH, MCH3 and MCNa were synthesized using different chemical activators like HNO3, H3PO4 and NaOH respectively. Structural and morphological features of the adsorbents before and after magnetization were determined by XRD, FTIR, FESEM, EDX and TGA. BJH nitrogen adsorption–desorption isotherm was used to find the surface area and pore size of adsorbents while the surface charge was determined by measuring zeta potential. FESEM images clearly showed the incorporation of magnetite nanoparticles into a porous network. The XRD further confirmed the formation of magnetite nanoparticles within the network of porous carbon with average crystallite sizes of 6.3, 5.8, 5.5 nm for MCH, MCH3 and MCNa respectively. To examine the adsorption behaviour of As(III) onto the MAC, batch adsorption experiments were conducted with the effect of different parameters like initial concentration, temperature, time, amount of adsorbent and pH. The results showed that MCNa is a potential adsorbent for As(III) with removal efficiency of 99%. Overall adsorption process follows pseudo 2nd order kinetics while the Langmuir model was found well applicable to the experimental data. Thermodynamics of adsorption and desorption studies suggest that chemisorption is a predominant adsorption mechanism. Cost-effectiveness, novelty and magnetic recovery are the key features making onion-based MAC a potential adsorbent for the removal of As(III) from contaminated water

Impact of Photolysis and TiO₂ on Pesticides Degradation in Wastewater

Pesticide residues are harmful to the environment and human and animal health even at low levels because of long-term bioaccumulation. In this study, photolysis was applied to treat three representative water samples: aqueous atrazine and dimethoate solutions as target pesticides, as well as wastewater and agriculture wastewater containing pesticide residue. It was performed using ultraviolet (UV) irradiation at two wavelengths (254 and 306 nm) with exposure times ranging from 2 to 12 h in the presence and absence of a photocatalyst to identify the optimal degradation conditions. Extraction and analyzation process were performed by the Quick Easy Cheap Effective Rugged Safe (QuEChERS) methods and gas chromatography–tandem mass spectrometry with triple quadrupole detector (GC–MSMS/TQD), respectively. Photodegradation increased with an increase in exposure time and the TiO2 catalyst was beneficial for degradation. Both selected irradiation wavelengths were effective, although the wavelength of λ = 306 nm was the most efficient

Impact of Photolysis and TiO2 on Pesticides Degradation in Wastewater

Pesticide residues are harmful to the environment and human and animal health even at low levels because of long-term bioaccumulation. In this study, photolysis was applied to treat three representative water samples: aqueous atrazine and dimethoate solutions as target pesticides, as well as wastewater and agriculture wastewater containing pesticide residue. It was performed using ultraviolet (UV) irradiation at two wavelengths (254 and 306 nm) with exposure times ranging from 2 to 12 h in the presence and absence of a photocatalyst to identify the optimal degradation conditions. Extraction and analyzation process were performed by the Quick Easy Cheap Effective Rugged Safe (QuEChERS) methods and gas chromatography–tandem mass spectrometry with triple quadrupole detector (GC–MSMS/TQD), respectively. Photodegradation increased with an increase in exposure time and the TiO2 catalyst was beneficial for degradation. Both selected irradiation wavelengths were effective, although the wavelength of λ = 306 nm was the most efficient

Designing Click One-Pot Synthesis and Antidiabetic Studies of 1,2,3-Triazole Derivatives

In the present study, a new series of 1,2,3-triazole derivatives was synthesized via a click one-pot reaction. The synthesized compounds were found to be active during molecular docking studies against targeted protein 1T69 by using the Molecular Operating Environment (MOE) software. The designed and synthesized compounds were characterized by using FT-IR, 1H-NMR and LC-MS spectra. The synthesized triazole moieties were further screened for their α-amylase and α-glucosidase inhibitory activities. The preliminary activity analysis revealed that all the compounds showed good inhibition activity, ranging from moderate to high depending upon their structures and concentrations and compared to the standard drug acarbose. Both in silico and in vitro analysis indicated that the synthesized triazole molecules are potent for DM type-II. Out of all the compounds, compound K-1 showed the maximum antidiabetic activity with 87.01% and 99.17% inhibition at 800 µg/mL in the α-amylase and α-glucosidase inhibition assays, respectively. Therefore these triazoles may be further used as promising molecules for development of antidiabetic compounds

Highly selective simultaneous electrochemical detection of trace level of heavy metals in water samples based on the single-crystalline Co3O4 nanocubes modified electrode

© 2021 Elsevier B.V.This study discussed the simultaneous electrochemical detection of highly toxic Pb2+, Cu2+, Hg2+ heavy metals by the Co3O4 modified electrode. The Co3O4 nanocubes (Co3O4-NC) are prepared by the facile hydrothermal synthesis route which produces highly crystalline particles without an annealing process. The structural properties are characterized by XRD, Raman, XPS, FESEM, and HRTEM analysis. The SAED pattern endorses the single-crystalline nature of Co3O4-NC. The prepared material was subjected to detect the heavy metals electrochemically via DPV techniques. The Co3O4-NC/SPCE revealed good electroanalytical activity towards both individual and simultaneous detection of heavy metals. The developed heavy metal sensor exhibited good sensitivity (16.73 ± 0.8 µA µM−1 cm−2 for Pb2+, 11.46 ± 0.5 µA µM−1 cm−2 for Cu2+, and 16.86 ± 0.7 µA µM−1 cm−2 for Hg2+) and LOD (4.1 ± 0.2, 0.9 ± 0.04, 0.1 ± 0.005 nM for Pb2+, Cu2+, Hg2+, respectively) in the simultaneous detection. Moreover, the Co3O4-NC/SPCE exhibited high selectivity with the other potential interfering metal ions and nitro compounds in tap water and pond water samples. Additionally, the Co3O4-NC/SPCE reveals good recoveries of about 100–101.5% for tap water and 97–101% for pond water samples. Hence, our proposed Co3O4-NC/SPCE is a good electrode material for the determination of toxic heavy metal pollutants in real-time monitoring sensor devices

Designing Optically & Utilization of Thermopile Chip with Resonant Cavity Absorber Structure as IR Absorber

This paper presents a novel thermopile chip in which the resonant cavity structure was fully utilized as an absorber by an optical design. The resonant cavity absorber structure was designed using Al as anthe bottom reflective metal layer, air as the intermediate dielectric layer, and SiO2/TiN/Si3N4 sandwich layers as the top absorption layer, while the bottom reflective metal (Al) was deposited on the cold junctions of the thermopile. The simulation and calculation results show that the thermopile chip with resonant cavity absorber structure not only has great infrared absorption in the wide infrared absorption range but also can effectively prevent the cold junctions from absorbing infrared radiation and inhibit the rise of temperature. As a result, the temperature difference between the hot junctions and the cold junctions is increased, and the responsivity of the thermopile chip is further improved. Moreover, the duty cycle of the thermopile chip is greatly improved due to the double-layer suspension structure. Compared with the traditional thermopile chip structure, the sizes of the thermopile chip with the resonant cavity absorber structure can be further reduced while maintaining responsivity and specific detectivity

Designing Highly Active S-g-C₃N₄/Te@NiS Ternary Nanocomposites for Antimicrobial Performance, Degradation of Organic Pollutants, and Their Kinetic Study

The current research is about the synthesis of pure nickel sulfide, a series of Te (0, 0.5, 1, 1.5, 2, and 3 wt.%)-doped NiS (Te@NiS) nanoparticles (NPs), and a series of S-g-C3N4 (10, 30, 50, 70, and 80 wt.%)/Te@NiS nanocomposites (NCs), fabricated through a hydrothermal route. XRD and FTIR spectroscopic techniques demonstrated the successful synthesis of NPs and NCs. SEM-EDX images confirmed the flakelike structure and elemental constituents of the fabricated materials. Tauc plots were drawn, to calculate the band gaps of the synthesized samples. Te doping resulted in a significant reduction in the band gap of the NiS NPs. The photocatalytic efficiency of the NPs and NCs was investigated against MB, under sunlight. The results obtained for the photocatalytic activity, showed that 1%Te@NiS nanoparticles have an excellent dye degradation capacity in sunlight. This was made even better by making a series of SGCN/1% Te@NiS nanocomposites with different amounts of S-g-C3N4. When compared to NiS, Te@NiS, SGCN, and 70%SGCN/1%Te@NiS, the 70%SGCN/1%Te@NiS NCs have excellent antifungal ability. The higher impact of SGCN/Te@NiS, may be due to its enhanced ability to disperse and interact with the membranes and intracellular proteins of fungi. The 70%SGCN/1%Te@NiS NCs showed excellent antibacterial and photocatalytic efficiency. Thus, the 70%SGCN/1%Te@NiS NCs might prove fruitful in antibacterial and photocatalytic applications

Improvement in Optoelectronic Properties of Bismuth Sulphide Thin Films by Chromium Incorporation at the Orthorhombic Crystal Lattice for Photovoltaic Applications

By using the chemical bath deposition approach, binary bismuth sulphides (Bi2S3) and chromium-doped ternary bismuth sulphides (Bi2−xCrxS3) thin films were effectively produced, and their potential for photovoltaic applications was examined. Structural elucidation revealed that Bi2S3 deposited by this simple and cost-effective method retained its orthorhombic crystal lattice by doping up to 3 at.%. The morphological analysis confirmed the crack-free deposition, hence making them suitable for solar cell applications. Optical analysis showed that deposited thin films have a bandgap in the range of 1.30 to 1.17 eV, values of refractive index (n) from 2.9 to 1.3, and an extinction coefficient (k) from 1.03 to 0.3. From the Hall measurements, it followed that the dominant carriers in all doped and undoped samples are electrons, and the carrier density in doped samples is almost two orders of magnitude larger than in Bi2S3. Hence, this suggests that doping is an effective tool to improve the optoelectronic behavior of Bi2S3 thin films by engineering the compositional, structural, and morphological properties

Construction of a binary S-scheme S-g-C3N4/Co-ZF heterojunction with enhanced spatial charge separation for sunlight-driven photocatalytic performance

A step-scheme (S-scheme) photocatalyst made of sulfurized graphitic carbon nitride/cobalt doped zinc ferrite (S-g-C3N4/Co-ZF) was constructed using a hydrothermal process because the building of S-scheme systems might increase the lifespan of highly reactive charge carriers. Utilizing cutting-edge methods, the hybrid photocatalyst was evaluated by employing TEM, XPS, XRD, BET, FTIR, transient photo-response, UV-vis, EIS and ESR signals. In order to create a variety of binary nanocomposites (NCs), nanoparticles (NPs) of 6% cobalt doped zinc ferrite (Co-ZF) were mixed with S-g-C3N4 at various concentrations, ranging from 10 to 80 wt%. For photocatalytic dye removal, a particular binary NC constructed between S-g-C3N4 and Co-ZF produces a huge amount of catalytic active sites. The findings showed that loading of S-g-C3N4 on 6% Co-ZF NPs serves as a good heterointerface for e−/h+ separation and transportation through the S-scheme S-g-C3N4/Co-ZF heterojunction. By boosting the hybrid system\u27s BET surface area for the photocatalytic process, the addition of 6% Co-ZF improves the system\u27s ability to absorb more sunlight and boosts its photocatalytic activity. The highest photo-removal effectiveness (98%), which is around 2.45 times higher than that of its competitors, was achieved by the hybrid photocatalyst system with an ideal loading of 48% Co-ZF. Furthermore, the trapping studies showed that the primary species involved in the MB aqueous photo-degradation were ˙OH− and h