Wet Chemical Approach Research Articles

Operando elucidation of hydrogen production mechanisms on sub-nanometric high-entropy metallenes

Precise morphological control and identification of structure-property relationships pose formidable challenges for high-entropy alloys, severely limiting their rational design and application in multistep and tandem reactions. Herein, we report the synthesis of sub-nanometric high-entropy metallenes with up to eight metallic elements via a one-pot wet-chemical approach. The PdRhMoFeMn high-entropy metallenes exhibit high electrocatalytic hydrogen evolution performances with 6, 23, and 26 mV overpotentials at −10 mA cm−2 in acidic, neutral, and alkaline media, respectively, and high stability. The electrochemical measurements, theoretical simulations, and operando X-ray absorption spectroscopy reveal the actual active sites along with their dynamics and synergistic mechanisms in various electrolytes. Specially, Mn sites have strong binding affinity to hydroxyl groups, which enhances the water dissociation process at Pd sites with low energy barrier while Rh sites with optimal hydrogen adsorption free energy accelerate hydride coupling, thereby markedly boosting its intrinsic ability for hydrogen production.

Multishell hierarchical GCNF/PANI/NiCo-LDH nanofibers film for high-performance supercapacitors

In the domain of supercapacitor investigation, nickel cobalt layered double hydroxides (NiCo-LDH), regarded as a promising battery material, have garnered significant attention. However, the inherent drawbacks of low conductivity and pronounced agglomeration in single-component NiCo-LDH hinder the achievement of satisfactory overall performance. Thus, a key challenge remains in the rational design of multi-component composite materials incorporating NiCo-LDH, carbon materials, and conductive polymers to enhance their electrochemical properties. In this study, we successfully fabricated multishell hierarchical fiber films of GCNF/PANI/NiCo-LDH through simple wet-chemical approach. This novel architecture features graphene-coated electrospun carbon nanofibers (GCNF) serving as a self-supporting carbon framework, polyaniline (PANI) acting as the conductive layer, and NiCo-LDH contributing a high faraday capacity. Utilizing the enhanced cooperative effects between the various components, the enhanced GCNF/PANI/NiCo-LDH electrode exhibits remarkable specific capacity (347.1 mAh g-1, 2499 F g-1 at 1 A g-1) alongside exceptional rate performance (maintaining 56.5% capacity at 20 A g-1). Moreover, when an asymmetric supercapacitor (ACS) is constructed using active carbon (AC) as the cathode and GCNF/PANI/NiCo-LDH as the anode, it demonstrates remarkable energy storage capabilities. Specifically, it achieves an impressive energy capacity of 43.8 Wh kg-1, along with a high power exceptional durability, with a capacitance retention of 88.8% even after 2000 cycles. This study presents a novel approach for designing high-performance density of 937.5 W kg-1. Additionally, it exhibits core-triple-shelled hierarchical materials in the field of energy storage devices.

Bimetallic PdPt Nanoparticles Decorated PES Membranes for Enhanced H2 Separation.

Hydrogen separation has significant importance in diverse applications ranging from clean energy production to gas purification. Membrane technology stands out as a low-cost and efficient method to address the purpose. The development of efficient gas-sensitive materials can further bolster the membrane's performance. In this pursuit, bimetallic PdPt nanoparticles were synthesized using a wet chemical approach and were strategically decorated onto poly(ether sulfone) (PES) membranes. The fibrous morphology of the PES membranes provided an ideal platform for the decoration of nanoparticles, promising enhanced gas transport properties. Prior to the attachment of nanoparticles, the membranes were pretreated under UV light to enhance their surface properties and facilitate improved adhesion. The synthesized bimetallic nanoparticles were characterized by using transmission electron microscopy and X-ray photoelectron spectroscopy for their morphological and elemental analysis. Furthermore, the engineered membranes were characterized using various techniques, such as Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and field emission scanning electron microscopy (FESEM) with rigorous scrutiny to ensure a comprehensive understanding of their structural, chemical, and morphological properties. The membranes were examined for their separation performance using pure H2, N2, and CO2 gases, and the results revealed a 30% increment in H2 permeability and 40 and 42% increments in H2/CO2 and H2/N2 selectivity, respectively. These findings confirmed the critical role of tailored material design and synthesis strategies in advancing membrane technologies for H2 separation applications.

Modulation of ZrO2-Ag2O-MoO3 nanocomposite into ultrasensitive hydrazine electrochemical sensor for environmental remediation

Herein, a facile single-step wet chemical approach was executed for the composition of semiconductor ternary metal oxides (TMO) i.e., ZrO2-Ag2O-MoO3 nanocomposite (NC) in an alkaline medium. For structural as well as morphological elucidation, the calcined nanocomposite was characterized through ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), powdered X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) and Brunauer-Emmett-Teller (BET) analysis. Later, the glassy carbon electrode (GCE) was modified into a highly responsive as well as selective hydrazine (HDZN) electrochemical probe (ZrO2-Ag2O-MoO3-NC/PEDOT:PSS/GCE) by the fabrication of thin layered ZrO2-Ag2O-MoO3 NC onto GCE facilitated by 5 % PEDOT:PSS as conducting polymer binder. While examining the analytical parameters through novel current–potential (I-V) electrochemical approach, for the first time, the newly designed electrochemical probe, as selective hydrazine sensor, happened to own the low detection limit (LOD; 0.028 pM) with greater sensitivity (33.86 μAμM−1cm−2) and broad linear dynamic range (LDR; 0.1 M–1.0 nM) in addition to coefficient of correlation (r)/r2 square (r = 0.9941, r2 = 0.9882) and low limit of quantification (LOQ; 0.093 pM). Furthermore, reproducibility as well as prolonged stability of this newly proposed probe towards hydrazine were also assessed and found to be reliable in short response time. Hence, this work presents an inaugural report about the sensing of HDZN through the newly designed non reported ZrO2-Ag2O-MoO3-NC/PEDOT:PSS/GCE via an economical as well as novel electrochemical, current–potential (I-V), approach. Additionally, this proposed method is equally responsive towards both environmental and extracted real samples analysis on large scale.

Enhanced Catalyst Recovery and Photocatalytic Degradation of Rhodamine B and Methylene Blue Using a ZnO/TiO2/Fe3O4 Nanocomposite: Physicochemical Characteristics and Environmental Implications

AbstractA facile wet chemical approach was adopted to synthesize zinc oxide, titanium dioxide, and iron (II, III) oxide, followed by the synthesis of ZnO–TiO2–Fe3O4 nanocomposite via physical mixing. The synthesized nanoparticles were characterized using X‐ray diffraction, UV–visible spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and energy‐dispersive X‐ray spectroscopy to investigate various physical and chemical characteristics of the prepared samples. Furthermore, the catalytic reduction of methylene blue (MB) and rhodamine B (Rh B) dyes was carried out using prepared nanomaterials as catalysts under UV–visible light illumination. It was observed that the degradation efficiency of the nanocomposite was equivalent to or slightly better than TiO2 nanoparticles and higher than ZnO nanoparticles against both dye solutions. Its removal efficiency using an external magnetic field is much higher than that of the constituent nanoparticles, owing to its higher saturation magnetization. So, the obtained results suggest that the produced nanocomposite can be employed as a high‐potential catalyst for reducing organic dyes and pollutants in wastewater treatments.

Bacterial Responses and Material-Cell Interplays With Novel MoAlB@MBene.

Developing efficient antibacterial nanomaterials has potential across diverse fields, but it requires a deeper understanding of material-bacteria interactions. In this study, a novel 2D core-shell MoAlB@MBene structure is synthesized using a mild wet-chemical etching approach. The growth of E. coli, S. aureus, and B. subtilis bacteria in the presence of MoAlB@MBene decreased in a concentration-dependent manner, with a prolonged lag phase in the initial 6h of incubation. Even under dark conditions, MoAlB@MBene triggered the formation of intercellular reactive oxygen species (ROS) and singlet oxygen (1O2) in bacteria, while the bacteria protected themselves by forming biofilm and altering cell morphology. The MoAlB@MBene shows consistent light absorption across the visible range, along with a distinctive UV absorption edge. Two types of band gaps are identified: direct (1.67eV) and indirect (0.74eV), which facilitate complex light interactions with MoAlB@MBene. Exposure to simulated white light led to decreased viability rates of E. coli (20.6%), S. aureus (22.9%), and B. subtilis (21.4%). Altogether, the presented study enhances the understanding of bacteria responses in the presence of light-activated 2D nanomaterials.

Synthesis and properties of tailored β‐tricalcium phosphate for bone filler applications

AbstractThe present work reports the synthesis of highly phase pure (> 95%) β‐TCP and its subsequent conversion into granules for bone graft applications, using an industrial scale proprietary manufacturing route. Following the wet chemical approach, several process parameters, were adjusted for large volume synthesis, including pH, precursor concentration, and ripening time. The granulation process is tailored to facilitate the scalibility and control over morphology, porosity, and pore size. X‐ray diffraction analysis confirms the presence of pure β‐TCP phase where as Ca/P molar ratio of 1.497 was determined using ICP‐OES. Fourier transform infrared spectroscopy depicts the presence of PO43− as a major molecular group. Scanning electron microscopy (SEM) images of the β‐TCP powders reveal necking features, a characteristic morphology of β‐TCP. SEM images of the β‐TCP granules reveal microporosity, which aids in triggering a biological response. The TGA‐DTA curve suggests that the weight loss in pure β‐TCP is twice as compared with β‐TCP containing hydroxyapatite. Furthermore, these β‐TCP granules were clinically tested in a few orthopedic and spine surgeries. In all the treated patients, β‐TCP granules did not induce any pus formation or infection at the surgical sites, thereby establishing clinically relevant biocompatibility properties.

Trace Amount of Ir Decorated NiFe Phosphide In-Situ Grown on Carbon Cloth as Cost-Effective Electrocatalyst for Oxygen Evolution Reaction.

Cost-effective electrocatalysts is a key constituent to establish the balance of cost and catalytic efficiency for oxygen evolution reaction (OER) via water electrolysis in the area of energy conversion and storage. NiFe phosphide decorated with trace amount of iridium (Ir) species in-situ grown on carbon cloth was prepared by a facile wet chemistry approach followed by a phosphorization post-treatment at a relative low temperature. The optimal electrocatalyst, Ir2-NiFePx/CC, exhibits excellent OER activity, with an low overpotential of 190 mV at 10 mA cm-2 for alkaline OER, and a desirable long-term durability over 90 h. The outstanding OER performance stems from the structural evolution via phosphorization process, Ir decoration with more high-valence stated Ir4+ species, and tight connection between individual components of the electrode, which gives rise to the strong activity to the active sites and faster reaction kinetics in the alkaline OER process. Mover, the Ir loading was as low as approximately ~1.7 wt % (0.29 mg cm-2), showing promissing propective in cost-effective OER.

Development of 2D Ir-DMG nanosheets as a colorimetric sensor probe for Ni (II) sensing and a highly sensitive, reliable, and portable colorimetric sensor device for environmental analysis

The era of nanomaterials made a revolutionary change in colorimetric sensing with ultra-high sensitivity, improved reactivity, and enhanced photoactivity. The first-ever novel 2D metal–organic nanosheets were synthesized using IrCl3 and Dimethylglyoxime (DMG) by probe ultrasonication (PUS) followed by a solvothermal wet-chemical approach. This material has shown a rapid color change from yellow to crimson red with Ni (II) after the formation of complex. The UV–visible absorption spectra are the conventional methodology for colorimetric sensors and here, it was given a perfect linear relationship with an R2 of 0.99 and an LOD of 1.60 µM (0.1 ppm). The average calculated molar extinction coefficient for this system was 1889.30 M−1 cm−1. This is comparatively high absorptivity value. In addition, a novel Arduino-based colorimetric sensor device and corresponding software were developed under the name of “Chrom Metrics”. This Arduino device is unique since it can sense all wavelengths and the combined RGB delta E values. Therefore, it can provide more information/rationale for colorimetry than other devices/methods. The same Ir-DMG & Ni (II) system showed a perfect linear relationship with an R2 of 0.98 and a LOD of 0.85 µM (0.05 ppm) by the data obtained from this sensor device. Thus, this new device is easier and more accurate, highly efficient, rapid, highly selective, and sensitive.

Effect of Hexamethylenetetramine concentration on the structural, morphological, optical and bactericidal action of Eu-doped TiO2 quantum dots derived through wet chemical method

Recently, it has been established that bacteria are quickly developing resistance to traditional antibiotics; as a result, one of the most significant challenges facing the healthcare sector is treating illnesses linked to bacterial infections. In this work, we used a simple wet chemical approach to easily prepare pure TiO2 and Eu-doped TiO2 quantum dots (QDs) with different hexamethylenetetramine (HMT) concentrations: 0.1, 0.15, and 0.2 M. As indicated by XRD results, the pure TiO2 possesses the tetragonal anatase phase, while the Eu-doped TiO2 samples prepared with the support of HMT content during sample synthesis promotes the amorphous phase. The Eu-doped TiO2 sample prepared at 0.1 M HMT has an almost uniform distribution of ultra-fine QDs, with an average particle size distribution of 2.05 ± 0.17 nm, according to the TEM image. The Eu 3d core level doublet at 1134.29 and 1164.21 eV, which correspond to Eu3+3d5/2 and Eu3+3d3/2, respectively, is displayed in the XPS data for the sample prepared at 0.1 M HMT. Based on the findings of the Tauc plot, the sample prepared at 0.2 M HMT is found to have a larger optical band gap than the pure TiO2 and Eu-doped TiO2 samples prepared at different HMTA concentrations. According to antibacterial tests, the zone of inhibition for E. coli increases from 7 ± 0.55 to 12 ± 0.60 when the concentration of the Eu-doped TiO2 sample prepared at 0.15 M HMT is increased from 100 to 300 µg/mL. In the field of biomedical application, this enhanced antibacterial activity of Eu-doped TiO2 QDs can be utilized to create a potent medication for bacterial resistance.

Z-scheme ZnIn2S4/CuxO heterostructure on flexible substrate for efficient photothermal catalytic CO2 reduction

The ZnIn2S4 nanosheets were successfully synthesized on the surface of compacted stainless steel mesh using a simple solvothermal method, and further modified with CuxO nanoparticles to form ZnIn2S4/CuxO heterojunction photocatalyst via a wet chemistry approach. These photocatalysts were then utilized for photothermal catalytic CO2 reduction under full spectrum solar light. The experimental results demonstrated that the deposition of the photocatalyst on the flexible substrate effectively prevented the aggregation of ZnIn2S4 nanosheets. The incorporation of CuxO nanoparticles enhanced the specific surface area of the photocatalyst, and created a Z-scheme heterojunction with ZnIn2S4 to improve the utilization efficiency of photogenerated electrons. It was noteworthy that the dark red CuxO exhibited a full spectrum response and excellent photothermal effect, thereby facilitating carrier migration and reducing CO2 catalytic reaction barriers. Consequently, the optimized ZnIn2S4/CuxO exhibited significantly enhanced CO2 to CO yield of 1515.8 μmol m-2h−1 and CH4 yield of 1579.4 μmol m-2h−1, which was about 7.5 and 7.6 times higher than those achieved by pure ZnIn2S4, respectively. Furthermore, this study provided detailed insights into the mechanism of photocatalytic CO2 reduction over composite material as well as valuable guidance for designing immobilized photocatalysts with high activity for CO2 reduction.

Insights on pH-dependent Physicochemical Properties and Supercapacitance Ability of α-MoO3

The transition towards supercapacitors for efficient energy storage provides a dynamic outcome for the global warming. The MoO3 samples were prepared at various pH using facile wet-chemical approach. The orthorhombic phase (α-MoO3) was confirmed from structural investigations namely XRD, and Raman. It is also evident that the prepared samples show layered structure of MoO3, which contributed in improving the efficiency of the supercapacitor application. The morphological analysis from SEM micrographs showed a slight agglomeration. The CV studies revealed that the sample prepared at pH-10 displayed a higher specific capacitance.

Weakening O-Intermediates Adsorption Strength Over the Pd Metallene via Lewis-Acidic Site Modulation for Enhanced Oxygen Reduction.

The reasonable design and modulation of the electronic properties of Pd metallene are acknowledged as a promising avenue for enhancing the oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs), yet they remain a formidable challenge. Herein, a thin-sheet structure of Zr-doped Pd metallene (PdZr metallene) with abundant defects is proposed using a facile wet-chemical approach for efficient and highly durable ORR electrocatalysis. Multiple microstructural analyses uncover that orchestrated electronic and oxophilic regulation of PdZr metallene via Lewis-acidic Zr site modulation could concurrently optimize the electronic configuration of Pd, downshift the d-band center of Pd, and, thus, promote the intrinsic activity. Benefiting from the unique two-dimensional morphology and electronic structure optimization facilitated by the Zr coupling effect, the resultant PdZr metallene demonstrates significantly enhanced ORR electrocatalytic performance in basic solutions, with a high half-wave potential (E1/2) of 0.87 V and commendable stability for 30 000 s, surpassing those of Pd metallene and various advanced Pd-based catalysts reported in the literature. Encouragingly, the PdZr metallene-based AEMFC achieves an increased maximum power density (90.4 mW cm-2) and impressive robustness over 12 h in an alkaline environment, manifesting the practical application of PdZr metallene in AEMFCs. This study showcases the applicability of PdZr metallene via Lewis acid site regulation for fabricating highly active electrocatalysts for high-performance AEMFCs.

Enhancing formate yield through electrochemical CO2 reduction using BiOCl and g-C3N4 hybrid catalyst

Electrochemical carbon dioxide (CO2) reduction with bismuth-based catalysts has been widely investigated in the recent few years. This is due to bismuth’s ability to perform selective electrochemical CO2 reduction reaction (eCO2RR) to an important C1 product, the formate (HCOO–). However, boosting the performance of such catalysts is a continuous investigation. In this work, enhancing the active sites for eCO2RR is investigated by forming nanocomposites with graphitic carbon nitride (g-C3N4). BiOCl is synthesized by a simple wet-chemical approach in the presence of glycine as size-controlling agent and formed into nanocomposites, which were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Infrared (IR) Spectroscopy and N2 physisorption. Linear Sweep Voltammetry (LSV) in argon and CO2-saturated atmosphere showed higher current values in the case of CO2. Chronoamperometries (CA) were recorded at −1.06 V vs Reversible Hydrogen Electrode (RHE) for 5400 s obtaining Faradic Efficiencies (FE) varying in the range of 70–77 % depending on the nanocomposites’ composition. In fact, 52.1 wt% BiOCl/g-C3N4 formed the highest yields for formate (with also the highest rate of formation of formate) together with a minimal production of H2 and CO. The effect of nano-structuration induced by glycine, used as a size-controlling agent, to form nanoplates was crucial: microplates of BiOCl produced without glycine showed an FE of 4 %, reaching 85 % in the case of the nanoplates. Post-electrocatalysis characterization revealed the possible role of Bi2O2CO3 as the active phase for eCO2RR.

Design of a hybrid nanoscaled skin photoprotector by boosting the antioxidant properties of food waste-derived lignin through molecular combination with TiO2 nanoparticles

TiO2 nanoparticles loaded with pistachio shell lignin (8 % and 29 % w/w) were prepared by a hydrothermal wet chemistry approach. The efficient interaction at the molecular level of the biomacromolecule and inorganic component was demonstrated by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Visible (UV–Vis), Fourier transform infrared (FT-IR), dynamic light scattering (DLS), and electron paramagnetic resonance (EPR) analysis. The synergistic combination of lignin and TiO2 nanoparticles played a key role in the functional properties of the hybrid material, which exhibited boosted features compared to the separate organic and inorganic phase. In particular, the hybrid TiO2-lignin nanoparticles showed a broader UV–Vis protection range and remarkable antioxidant performance in aqueous media. They could also better protect human skin explants from the DNA damaging effect of UV radiations compared to TiO2 as indicated by lower levels of p-H2A.X, a marker of DNA damage, at 6 h from exposure. In addition, the samples could protect the skin against the structural damage occurring 24 h post UV radiations by preventing the loss of keratin 10. These results open new perspectives in the exploitation of food-waste derived phenolic polymers for the design of efficient antioxidant materials for skin photoprotection in a circular economy perspective.

Photocatalytic applications of metal oxide-based nanocomposites for sustainable environmental remediation

Change in human lifestyle and excessive use of commercial products have caused an ecological deterioration. A major contribution towards this comes from the mixing of toxins and persistent organic pollutants into water bodies, which poses a serious risk to the ecosystem. In the above context, materials scientists are involved in the search for sustainable solutions to address the above environmental challenges by the development of advanced materials. In this study, we prepared nanocomposite materials such as; ZnO-SnO2 and ZnO-MoS2 by wet-chemical approach to degrade dye pollutants like Rhodamine B (RhB) and Congo red (CR) towards achieving environmental remediation. Powder X-ray diffraction (PXRD) measurement was done for structural characterization of the samples and the formation of the nanocomposite phase was validated by the above study. The goal of the field emission scanning electron microscopy (FESEM) study was to examine the morphology of the composites which was accompanied by the energy dispersive analysis of x-rays (EDAX) and electron mapping experiments which verified the presence of Zn, Sn, O, Mo, S elements in the respective samples. Fourier transformed infrared spectroscopy (FTIR) meas urement was conducted to investigate the vibrational properties of the samples. Photocatalytic measurement showed improved degradation efficiency of the composites as compared to the pristine samples. The degradation efficiency was found to increase with irradiation time and attained saturation after 180 min. ZnO-SnO2 nanocomposite show 91.23 % and 88.11 % of degradation for RhB and CR dyes respectively whereas 89.29 % and 83.25 % degradation have been obtained for ZnO-MoS2 for the same dyes. Several aspects of the experiment were varied, including the amount of catalyst employed, the initial dye concentration, and the pH levels, in order to assess the efficacy of the photocatalysts. Both the photocatalysts degraded CR dye most effectively at acidic pH, although RhB dye gets degraded more at neutral and alkaline pH. ZnO-SnO2 was found to be an effective photocatalyst for degrading RhB dye at neutral pH and CR dye at acidic pH. After multiple iterations of experimentation, the photocatalytic mechanism has been extensively described, and the stability and reusability of the photocatalysts have been ensured for effective environmental cleanup.

Luminescence and dielectric investigations of crystalline niobate nanoceramics prepared through aqueous chemical process

The present study reflects the synthesis of MgNb2O6 using hydrofluoric acid via a wet chemical approach, followed by characterizations involving XRD, electron microscopy, Raman spectroscopy, optical analyses, and impedance spectroscopy. The crystallite size of the synthesized material was determined to be 44 nm through XRD analysis. The lattice parameters of MgNb2O6 a, b, and c, were found to be 14.1998 Å, 5.6844 Å, and 4.9813 Å, respectively. Raman spectroscopy identified molecular bonds ranging from 253 to 1011 cm−1, mainly indicating the presence of metal oxide bonds. EDX spectra confirmed the presence of Mg, Nb, and O atoms in the prepared ceramics, indicating phase purity. FESEM analysis revealed a grain size of approximately 48 nm, with the presence of agglomerated grains. Bright spots in the SAED pattern observed by HRTEM confirmed the crystallinity of the prepared niobate materials, with the HRTEM microstructure showing a particle size near 49 nm. The crystallite size by XRD, grain size by FESEM, and particle size by HRTEM are in accordance with each other. The direct band gap was determined to be approximately 2.76 eV using UV-Visible spectroscopy. Additionally, MgNb2O6 materials exhibited a broad and strong photoluminescence emission near 445 nm with excitation at 270 nm, possibly indicating the presence of radiative defects in the crystalline nanostructure. Furthermore, impedance studies conducted between 40 and 110 MHz demonstrated a decrease in the dielectric constant at higher frequencies, reaching 21.06 at 110 MHz. A low dielectric loss was also observed at 110 MHz. The moderate band gap and strong room-temperature photoluminescence in the visible range make magnesium niobates suitable for possible applications in optical devices. This investigation shows that a dielectric constant near 21 and low dielectric loss can be achieved in the high-frequency range around 110 MHz.

Synthesis and Electrochemical Performance of High‐Entropy Spinel‐Type Oxides Derived from Multimetallic Polymeric Precursors

High‐entropy spinel‐type oxides are synthesized by a modified Pechini process, wet chemistry approach, and solid‐state synthesis method and characterized as anode materials for Li‐ion batteries. The Pechini process that involves chelation and polyesterification reactions facilitates the formation of high‐entropy spinel‐type oxides without compositional segregation at ≈600 °C as confirmed by in situ and ex situ XRD. XAFS analysis and the Rietveld refinement of room‐temperature neutron diffraction data suggest the composition (Mn0.05Fe0.48Co0.47, tetrahedral)(Cr0.61Mn0.52Fe0.11Co0.09Ni0.68, octahedral)O4 for phase‐pure specimens. Compared to high‐entropy spinel‐type oxides synthesized by the solid‐state method, the precursor‐derived materials demonstrate higher specific capacity as anodes, in which the materials without citric acid addition exhibit low capacity fading at high current densities and maintained a capacity of ≈200 mAh g−1 after 1000 cycles. The generation of a rock‐salt‐type phase during cycling is confirmed for the first time by in situ charging–discharging XRD. The charging–discharging of this anode material is achieved mainly through the embedding–disembedding of lithium ions in the lattice of the generated rock‐salt‐type phase.

Synthesis of Samarium Doped Tin Oxide Using Wet Chemical Precipitation Approach

Synthesis of Samarium Doped Tin Oxide Using Wet Chemical Precipitation Approach

FeVO4 nanoparticles for N-Alkylation of acetamides under blue light irradiation: Mechanistic insights and product characterization

This study aimed to synthesize FeVO4 nanoparticles using a wet-chemical approach. The nanoparticles were characterized and confirmed using various techniques. XRD (X-Ray Diffraction) confirmed the triclinic crystal system of the nanoparticles, and the crystallite size was calculated to be 33.5 nm. FE-SEM (Field Emission Scanning Electron) and HR-TEM (High- Resolution Transmission Electron Microscopy) confirmed the spherical nature of FeVO4 with particle size of 41.8 nm. Further SAED (Selected Area Electron Diffraction) confirmed the crystallinity nature of the nanoparticles. Optical studies and EIS (Electrochemical Impedance Spectroscopy) revealed their photocatalytic behavior. The pore volume and diameter of the FeVO4 nanoparticles were 0.024 and 2.102 nm, respectively. The obtained nanoparticles were employed as photocatalysts for the N-alkylation of N-phenyl and N-pyridinyl acetamides under blue LED light. The reaction progressed well in approximately 8–12 h with a yield of 60–90 %. The photocatalytic evaluation was optimized under various conditions and provided with mechanistic investigations. The novel N-alkylated analogues were verified by FT-IR, 1H NMR, 13C NMR, and HRMS. The present work explores a novel approach to N-alkylation using FeVO4 nanoparticles in an effective manner. This may lead to new advancements in FeVO4 based photocatalysts for numerous organic transformations.