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Abstract In this work, we reported the synthesis of honey bee (Apis mellifera) venom-derived nanoparticles via a hydrothermal method. This method not only ensures the preservation of the bee venom’s bioactive components but also enhances their potential stability, thus broadening the scope for their applications in the biomedicinal field. The synthesis method started with the homogenization suspension of bee venom, followed by its hydrothermal process to synthesize bee venom nanoparticles (BVNPs). The successful synthesis of BVNPs was characterized using various characteristic techniques such as Ultraviolet–visible (UV–Vis) spectroscopy, Fourier Transforms Infrared (FTIR) Spectroscopy, Zeta Potential (ZP), Liquid Chromatography-Mass Spectrometry (LCMS), and Transmission Electron Microscopy (TEM). The synthesis of BVNPs through biosynthesis is shown by the visible violet-brown color development at 347 nm by UV–Vis spectroscopy. FTIR analysis revealed the presence of several functional groups in the BVNPs, including alcohols (–OH), phenols (C6H5–), carboxylic acids (–COOH), amines (–NH2, –NH–), aldehydes (–CHO), ketones (–CO–), nitriles (–CN), amides (–CO–N–), imines (–CNH–), esters (–COO–), and polysaccharides. These functional groups, as confirmed by their specific stretching and bending vibrational modes, contribute to the diverse biological activities of BVNPs, including cytotoxicity against MCF-7 breast cancer cells. The ZP of the BVNPs indicated good colloidal stability at − 45 mV. LCMS analysis confirmed the presence of major bioactive molecules, including melittin & apamin and TEM analysis shows the BVNPs exhibited a quasi-spherical shape with good dispersion, the average size was approximately 25 nm, with some being smaller (quantum dots) and interplanar spacing of 0.236 nm indicated a highly ordered crystalline structure. Moreover, the anticancer efficacy of the BVNPs was ascertained through in vitro assays against MCF-7 breast cancer cells, showing a dose-dependent cytotoxic effect. The findings of this study underscore the viability of hydrothermal synthesis in producing biologically active and structurally stable BVNPs, with a significant potential for anticancer activities. Graphical Abstract

Abstract Infections originating from pathogenic microorganisms can significantly impede the natural wound-healing process. To address this obstacle, innovative bio-active nanomaterials have been developed to enhance antibacterial capabilities. This study focuses on the preparation of nanocomposites from thermally reduced graphene oxide and zinc oxide (TRGO/ZnO). The hydrothermal method was employed to synthesize these nanocomposites, and their physicochemical properties were comprehensively characterized using X-ray diffraction analysis (XRD), High-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FT-IR), Raman spectroscopy, UV-vis, and field-emission scanning electron microscopy (FE-SEM) techniques. Subsequently, the potential of TRGO/ZnO nanocomposites as bio-active materials against wound infection-causing bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, was evaluated. Furthermore, the investigated samples show disrupted bacterial biofilm formation. A reactive oxygen species (ROS) assay was conducted to investigate the mechanism of nanocomposite inhibition against bacteria and for further in-vivo determination of antimicrobial activity. The MTT assay was performed to ensure the safety and biocompatibility of nanocomposite. The results suggest that TRGO/ZnO nanocomposites have the potential to serve as effective bio-active nanomaterials for combating pathogenic microorganisms present in wounds.

This study explores the influence of hydrothermal temperatures on the synthesis of ZnO-Bentonite composites and their efficiency in the adsorption and photodegradation of Methylene Blue dye. ZnO nanoparticles were integrated into Na-Bentonite, with composites synthesized at hydrothermal temperatures of 100°C and 200°C. Various characterization techniques such as XRD, FTIR, UV-Vis DRS, TG-DTA and BET were utilized to analyze the structural and thermal properties. The results show that the composite synthesized at 200°C exhibits superior performance, with a maximum adsorption capacity of 120.48 mg/g at 50°C, significantly higher than the 49.26 mg/g achieved by the composite synthesized at 100°C. Moreover, the enhanced crystallinity and increased surface area, as evidenced by a 16 nm crystallite size at 100°C and 22 nm at 200°C, led to improved photocatalytic activity. The research concludes that higher hydrothermal temperatures improve both adsorption and photodegradation efficiency, making the composite synthesized at 200°C more effective for environmental applications.

The hydrothermal synthesis of Ba1−xCoxTiO3 (BCT) ceramic nanocrystals across varied substitution fractions (x = 0, …, 1) is the subject of this study. Hydrothermal synthesis is well known for producing high-purity and well-crystallized nanocrystals. A thorough examination is conducted to examine the effects on the structural and electrical properties of the resultant BCT nanocrystals by altering the cobalt substitution fraction. X-ray diffraction (XRD) is used to analyze the structure, while complex impedance spectroscopy (CIS) is used to analyze the electrical properties. As the cobalt content rises, XRD examination reveals a smooth transition from the ferroelectric BaTiO3 phase to the ferromagnetic CoTiO3 phase, offering extensive insights into the phase composition and crystallographic alterations. This phase shift is important because it creates new opportunities to adjust the properties of the material for particular uses. The electrical activity of BCT nanocrystals is clarified further by CIS measurements. A distribution of relaxation times, frequently linked to complex microstructures or heterogeneous materials, is suggested by the detected non-Debye relaxation. A thermally activated conduction process, in which higher temperatures promote the passage of charge carriers, is suggested by the temperature-dependent increase in conductivity. This behavior is strongly dependent on the cobalt content, suggesting that cobalt enhances electrical conductivity and crystallinity through a catalytic effect. A frequency-dependent dielectric constant that rises with temperature and cobalt content is shown by investigating the dielectric characteristics of BCT nanocrystals. Improved polarization mechanisms inside the material are suggested by this increase in dielectric constant, which may be the result of cobalt ion presence. With a thorough grasp of the dielectric behavior, the examination of the loss angle further validates the non-Debye relaxation process.

Like-caviar molybdenum ferrite nanoparticles (MoFe2O4 NPs) have been successfully synthesized via a hydrothermal route in the presence of the negative surfactant (sodium dodecyl sulfate (SDS)). SDS acts as a template, stabilizer, and stops the aggregating process through storage. The mean crystal size of MoFe2O4 NPs rises with decorating it with Al2O3. Based on SEM analysis, the shapes of MoFe2O4, Al2O3, and their composite demonstrated like-caviar, like-brain cells, and like-grains, respectively. Al2O3 has been chosen to incorporate with spinel MoFe2O4 to make it color more light, this crucial step is necessary to enhance their optical characteristics. FTIR spectra observed the MoFe2O4 NPs are inverse spinel. The photo-decolorization test employs indigo carmine (IC) as a model pollutant. The quantum yields (Φ) of IC dye decolorization with studied photocatalysts are low, which may be created by quencher materials, dimerization of dye molecules, and photophysical deactivation processes (ISC process). Moreover, the photocatalytic activity of using MoFe2O4 raised after being decorated with alumina, which revealed an increase in the surface acidity, hydroxyl group adsorption, size, band gap, pHpzc of MoFe2O4 from 2.9–3.6 to 4.2–5.9 after decorated alumina. This pH is suitable for decolorizing IC dye, which has a pH of solution equal to 5.3.

Hard carbons (HC) have been synthesized from D-glucose and pectin via a hydrothermal technique and pyrolized at 1200°C, 1400°C and 1600°C. Their structural evolution depending on the pyrolysis temperature was investigated with X-ray powder diffraction, Raman spectroscopy with additional characterization with scanning and transmission electron microscopy and gas adsorption/desorption measurements. More ordered and uniform structures were obtained at higher pyrolysis temperature. Correlations of the HC structure with the electrochemical properties as a negative electrode (anode) in potassium half-cells and interaction mechanism of K+ ions with HC were analyzed and discussed. The prevalence of pseudocapacitive contribution for K-ion interaction with HC was deduced from cyclic voltammograms. The hydrothermally pre-treated HC anodes annealed at higher temperature demonstrate less pseudocapacitive and more pronounced diffusion-controlled behavior causing a capacity decrease with increasing pyrolysis temperature from 277 mAh/g (1200°C) to 243 mAh/g (1400°C) and to 153 mAh/g (1600°C).

Abstract Bimetallic nickel‐iron based oxides are regarded as one of the most promising catalysts for the oxygen evolution reaction (OER). In this study, we show that the precursor metal salts can affect the OER activity of the resulting Ni/Fe oxide under the same hydrothermal synthesis conditions. Pure sulfate, pure nitrate and mixed sulfate/nitrate metal salts were used to fabricate NiFe based oxide materials and to study the importance of the precursor choice for the OER. The results show that the nature of the precursor used in the synthesis of the bimetallic nickel‐iron materials can influence different multi‐phase catalysts to form which effects the OER.

The demand for suitable electrode materials for energy storage devices, driven by increasing energy needs and environmental concerns, has led to the investigation of green synthesis methods. In this study, a composite material (rGO@NCQDs) comprising nitrogen-doped carbon quantum dots (NCQDs) derived from Moosa balbeesiaana peels and reduced graphene oxide (rGO) was synthesized via hydrothermal methods to evaluate its photophysical properties and electrochemical performance for supercapacitors applications. Additionally, the electrochemical behavior of rGONCQDs combined with Vanadium pentoxide (V2O5) was explored.Characterization techniques including FTIR spectroscopy revealed typical carbon-based material features in rGO-decorated NCQDs, and rGONCQDs@V2O5 composite. SEM analysis illustrated distinctive surface structures (mushroom-shaped for rGO@NCQDs and flowered-shaped for rGONCQDs@V2O5), while XRD confirmed crystalline structures with specific sizes.Photophysical investigations demonstrated significant Solvatochromic shifts and strong solute-solvent interactions in the composites. Electrochemical studies, including cyclic Voltammetry and Galvanostatic measurements, exhibited promising performance metrics. Specifically, rGO@NCQDs demonstrated a specific capacitance of 134.68 Fg−1 with excellent retention over 5000 charge-discharge cycles. In contrast, rGONCQDs@V2O5 exhibited a maximum specific capacitance of 562.62 Fg−1 at a scan rate of 10 mVs−1 and exceptional cycle stability (96 % retention over 5000 cycles).These findings highlight the potential of the synthesized composites as efficient electrode materials for supercapacitors, offering enhanced electrochemical performance and stability. The study underscores the importance of green synthesis approaches in developing functional materials for sustainable energy storage applications.

Objectives. To examine the general principles and recent advances in the synthesis of high-purity and high-homogeneity barium titanate powders in the manufacture of electronic components.Results. The main publications regarding the synthesis of barium titanate powder, including the works of recent years, were analyzed. The technological advantages and disadvantages of various synthesis methods were identified. Groups of methods based on solid-state interaction of reagents and methods of “wet chemistry” were also considered. The possibilities of producing barium titanate particles of non-isometric shapes for creating textured ceramics were discussed separately.Conclusions. Barium titanate is a well-known ferroelectric with a high dielectric constant and low dielectric loss. It is used as a component in ceramic electronic products, for example, capacitors, memory devices, optoelectronic devices, and piezoelectric transducers. The possibilities of producing functional ceramics based on barium titanate powder largely depend on its state and morphological characteristics, determined during the synthesis stage. The most important factors affecting the functional characteristics of ceramics are the purity and morphology of the powder raw materials used.

Currently, the search for new types of carriers for low-molecular weight substances, as well as the development of optimal methods for the eff ective encapsulation of these substances are important tasks of modern chemistry and pharmacology. However, there are still limitations in this area, among which one of the most signifi cant is the lack of the optimal carrier capable of stably retaining a low-molecular weight substance. The work presents hybrid polymer structures obtained by in situ hydrothermal synthesis as an eff ective candidate for these purposes. The fl uorescent dye rhodamine B has been used as a model low-molecular weight substance for encapsulation into the structures. The resulting hybrid polymer structures demonstrated good stability when stored in an aqueous environment for 336 h with the release of the low-molecular weight dye rhodamine B no more than 2%. In addition, the infl uence of the conditions for obtaining hybrid carriers (including the composition of the carriers (thickness of the polymer shell and the presence of a calcium carbonate core) and synthesis temperature) on their physical-chemical characteristics has been studied. Thus, the optimal approach for obtaining fl uorescent hybrid polymer carriers with a set of desired properties has been revealed. In particular, it has been shown that the optimal production conditions are hydrothermal synthesis temperature of 180 °C and the absence of CaCO3 core inside the polyelectrolyte shell which allow us to obtain a stable hybrid polymer carrier with bright fl uorescence. The results presented in this study can be used to create functional platforms and systems with tunable fl uorescent properties and the ability to deliver low-molecular weight substances.

Calcination temperature is a crucial parameter that can be easily controlled to induce a change in material properties. Herein, iron tungstate (FeWO4) was synthesized via a hydrothermal method using iron(II) sulfate heptahydrate and sodium tungstate dihydrate as precursors and calcined at the temperature between 300 oC and 700 oC. With increasing calcination temperature, the saturation magnetization of FeWO4 nanoparticles decreased from 6.6 emu/g for FeWO4 to 0.4 emu/g for FeWO4_700, whereas their band gaps increased from 1.95 eV for FeWO4 to 2.20 eV for FeWO4_700. More crystallinity and crystal defects, and morphological changes at higher calcination temperatures contributed to varying magneto-optical properties of FeWO4 nanoparticles.

Abstract KAlPO4F was prepared hydrothermally at 453 K, a time-saving method using cheap reagents. The white solid was characterized by different methods such as powder X-ray diffraction, thermal analysis, SEM and UV–Vis diffuse reflectance. The compound was successfully tested for the removal of methyl violet (MV), a hazardous dye. Experiments were carried out as a function of contact time, initial concentration, temperature and pH. The amount of dye uptake was found to vary with increasing initial solution pH and maximum adsorption was observed at pH 10; the equilibrium was attained in 270 min. The amount of dye uptake (mg/g) was found to increase with increase in dye concentration and contact time. The pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models were applied to fit the experimental data to elucidate the kinetic adsorption. The pseudo-second-order model was the best to describe the adsorption process. Different models analyzed the equilibrium isotherms; the applicability for the experimental data follows the order: Freundlich > Langmuir > Temkin. The thermodynamic parameters: ΔH° (39.034 kJ mol−1), ΔS° (134 J K−1 mol−1) and ΔG° (− 367.01 J mol−1) indicated that the adsorption process is endothermic and spontaneous with increasing disorder at the solid–solution interface.

Mercury, emitted from various industries, is toxic and has devastating environmental consequences. Therefore, it becomes imperative to monitor the levels of mercury closely. This work mainly focuses on preparing inexpensive zeolite-coated kaolin membranes for separating Hg2+ from water. The membrane support was prepared using kaolin (50 wt%), quartz (25 wt%), and calcium carbonate (25 wt%). This mixture was blended with a 3 % hydroxypropyl methylcellulose (HPMC) solution and then passed through an extruder to obtain tubular support, which was further sintered at 950 °C. The zeolite-coated membrane (ZP membrane) was fabricated by subjecting the sintered support to a 48-h hydrothermal synthesis in 7 Na2O: 1 Al2O3: 10 SiO2: 205H2O gel at 90 °C. The isoelectric point of the ZP membrane was estimated to be 4.5. The zeolite-coated membrane displayed a pure-water permeability of 22.7 × 10−9 m3/m2 s kPa, a porosity of 31.72 ± 0.86 %, and a pore size of 90 nm. The performance of the ZP membrane in separating the Hg2+ ion from an aqueous solution was investigated by pressure variations (69–345 kPa) and feed concentration (0.5–10 ppm). The results clearly showed that in all cases, the zeolite-P membrane exhibited more than 99 % rejection of Hg2+ ions from aqueous solutions during the filtration experiments. Thus, the prepared ZP membrane can effectively be used for the separation of Hg2+ ions from wastewater.

ABSTRACTAn effective low-cost nano NiO-In2O3 electrode material for oxygen evolution (OER) is presented. Electrochemical studies uncovered electrocatalytic recital in Ascorbic Acid, Hydrogen Peroxide (H2O2), and ethanol. The cubic crystal structure of NiO-In2O3 was revealed by XRD. FT-IR, FE-SEM and HR-TEM studies exploit the structure and morphology of NiO-In2O3. Electrochemistry of NiO-In2O3 uncovered high current density (900mA/cm2) at substantially low overpotential (230mV), realizing its OER recital. On top, high mass activity and turnover frequency by NiO-In2O3 comprehend improved electrical and semiconductive properties in H2O2. The NiO-In2O3 durability beyond 90 hours was estimated by chronopotentiometry (CP). The Impedance analysis (EIS) revealed low charge transfer resistance and high exchange current density. Given electrocatalytic studies, we found a direct relationship between NiO-In2O3 nanocomposite and the degradation of H2O2 compared to its counterparts. Hence, this strategy can be an alternative and potential source of hydrogen and oxygen production at commercial scale.Highlights A facile and effectual low-cost NiO-In2O3 electrocatalyst is developed for efficient OER in aqueous hydrogen peroxide.NiO-In2O3 nanocomposite showed high current density (900mA/cm2) at low overpotential grasping its oxygen evolution reaction (OER) concert.NiO-In2O3 Impedance analysis revealed its low charge transfer resistance, high exchange current density (Jexc.), high mass Activity, and high turnover frequency (TOF) in hydrogen peroxide, advocating enhanced electrical and semiconductive properties.NiO-In2O3 showed long-term durability (>90 h) at varying current densities, fostering its application as a potential electrocatalyst for OER/HER reactions.

In this study, a trisodium citrate (TSC)-assisted hydrothermal method is utilized to prepare three-dimensional hydroxyapatite (3D HA). Understanding the role of TSC in the preparation of 3D HA crystals may provide valuable methods to design advanced biomaterials. As one of the indexes of solution supersaturation, the initial pH (ipH) value can not only directly affect the nucleation rate, but also affect the growth of HA crystals. In this work, the effect of the ipH on the microstructure, particle size distribution, and specific surface area of the 3D HA is explored. Results showed that the morphology of 3D HA transformed from a bundle to a dumbbell ball and then a dumbbell with an increase in the ipH. A corresponding mechanism of such a structural evolution was proposed, providing inspiration for the fabrication of innovative 3D HA structures with enhanced biological functionality and performance.

This study aimed to prepare poorly ordered calcium silicate hydrate (C-S-H) via the hydrothermal synthesis method, using ground quartz sand powder and lime as starting materials. The fineness of quartz sand powder under different grinding time and varied grinding aids content was investigated. It further affected the formation of calcium silicate hydrate. Results showed that the main synthesized product was crystalline dicalcium silicate hydrate (C2SH) with a small amount of C-S-H when quartz sand was ground to 29.95 µm for D50, attributed to the coarse particle size with a low silica reaction rate. Increasing the grinding time and grinding aid content of quartz sand improved the silica reaction rate and accelerated the formation of calcium silicate hydrate. Adding 1‰ grinding aid content would greatly improve the grinding efficiency, and the particle size of quartz sand powder was greatly reduced to the smallest value recorded in this study (D50 was 21.08 µm), which was beneficial to the transformation of C-S-H from C2SH. Meanwhile, C-S-H underwent a change from having a flocculated morphology to a needle-like, short-rod-like and fibrous morphology.

In recent years the applicability of semiconductor nanomaterials is almost in every field of science and technology. In the current study, hybrid nanomaterials containing tungsten trioxide (WO3) and nickel oxide (NiO) supported on graphitic carbon nitride (gC3N4) were prepared by a simple hydrothermal technique. Synthesis was sequential requiring the individual preparation of gC3N4 and WO3 as preliminary. The desired composition of gC3N4, WO3, nickel nitrate, and a base was transferred to an autoclave and maintained at 180°C for 18 h. The resulting inorganic/organic hybrid was filtered, washed, dried, and named as inorganic/organic hybrid nanocomposite (HNC). Various compositions of HNC were prepared and characterized by Fourier transform infrared spectrometer (FT-IR), Ultra Violet-Visible Diffuse reflectance spectrometer (UV–Vis-DRS), X-ray diffractometer (XRD), and Field emission scanning electron microscope (FE-SEM). The FE-SEM images showed a sago-shaped embedded particle in gC3N4 layers with a 40–60 nm particle size. The band gap energy was found to be 2.69 eV from UV–Vis-DRS analysis. This proves the promising activity of sago-shaped HNC under sunlight radiation. Various preliminary and kinetic studies were conducted, and HNC possessed excellent photocatalytic activity for the degradation of an organic dye under sunlight. The photocatalytic activity for the degradation of dye by the prepared HNC was found to be two-fold when compared to the activity of pristine gC3N4 under sunlight irradiation.

Novel quantum materials offer the opportunity to expand next-generation computers, high-precision sensors, and new energy technologies. Among the most important factors influencing the development of quantum materials research is the ability of inorganic and materials chemists to grow high-quality single crystals. Here, the synthesis, structure characterization and magnetic properties of Na2Cu3(SeO3)4 are reported. It exhibits a novel two-dimensional (2D) structure with isolated layers of Cu nets. Single crystals of Na2Cu3(SeO3)4 were grown using a low-temperature hydrothermal method. Single-crystal X-ray diffraction reveals that Na2Cu3(SeO3)4 crystallizes in the monoclinic crystal system and has space group symmetry of P21/n (No.14) with a unit cell of a = 8.1704(4) Å, b = 5.1659(2) Å, c = 14.7406(6) Å, β = 100.86(2), V = 611.01(5) Å3 and Z = 2. Na2Cu3(SeO3)4 comprises a 2D Cu-O-Cu lattice containing two unique copper sites, a CuO6 octahedra and a CuO5 square pyramid. The SeO3 groups bridge the 2D Cu-O-Cu layers isolating the neighboring Cu-O-Cu layers, thereby enhancing their 2D nature. Magnetic properties were determined by measuring the magnetic susceptibility of an array of randomly oriented single crystals of Na2Cu3(SeO3)4. The temperature-dependent magnetic measurement shows an antiferromagnetic transition at TN = 4 K. These results suggest the fruitfulness of hydrothermal synthesis in achieving novel quantum materials and encourage future work on the chemistry of transition metal selenite.

Abstract Indirect carbonation, a technology to store CO2 and produce stable CaCO3 and MgCO3, involves elution of Ca and Mg from industrial waste and subsequent carbonation. Although substantial residual waste is generated after the elution of Ca and Mg, its recycling attributes have not been adequately scrutinized. The residual waste has lower Ca and Mg contents and higher Si and Al contents than those of the raw material (i.e., industrial waste). This study involves the hydrothermal synthesis of zeolite-P using residual waste from indirect carbonation, conducted at both 100 and 180 ℃. The properties of these zeolites are compared with those synthesized from coal fly ash (CFA). The synthesized zeolites were characterized by X-ray diffraction, field emission scanning electron microscope, thermogravimetric analyzer, and Brunauer–Emmett–Teller (BET). A high zeolite conversion efficiency was achieved through a hydrothermal reaction (up to 87%), even though Si and Al were not added to the residual waste. Additionally, the cation exchange capacity and BET specific surface area of the synthesized zeolites were high (200 cmol kg−1 and 73 m2 g−1, respectively). These findings highlight the possibility of synthesizing zeolites using the residual waste from indirect carbonation as an alternative to conventional zeolite synthesis using industrial waste such as CFA. The synthesized zeolite-P is expected to be effective in wastewater treatment, detergent manufacturing, and water softening.

The aim of this work is to study the effect of the addition of nickel oxide nanoparticles in different concentrations to the polymer matrix of polyvinylpyrrolidone on the electrical and optical properties of the membrane. Nickel oxide nanoparticles were prepared by the hydrothermal method, and the nanoscale size of the particles was measured by scanning field emissions (SEM). To find out the crystal size, X-ray diffractivity (XRD) was carried out. the chemical bonds of composite membranes were determined by infrared spectroscopy (IR) examination .where the Ni-O bond appeared at wavenumber 408cm-1. The energy gap was calculated for the pure polymer and the composite polymer, and there was a decrease. The Hall Effect test was performed to measure the electrical properties of the composite and pure membrane and the results showed that the best conductivity For a composite membrane, at the nickel concentration (0.1) in the polymer matrix. As a result, a composite thin film of PVP-NiO NPs can be utilized as a semi-conductor in photo sensor and solar cell applications.

The crystal structure and morphology of photocatalysts play a crucial role in determining their photocatalytic performance. In this study, we synthesized and investigated 1D/2D Bi2S3 as a potential visible-light-activated photocatalyst for the reduction of aqueous Cr(VI). The 1D/2D Bi2S3 was synthesized using hydrothermal synthesis technique by heating Bi2(H2O)2(SO4)2(OH)2 precursor and sodium sulfide at 190 ℃ for 24 h, where the molar ratio of Bi to S elements in the reaction reagents was changed from 1:6 to 2:3. The structure, composition, and optoelectronic properties of the prepared Bi2S3 were characterized using X-ray diffraction, UV-vis diffuse reflectance spectra, field emission scanning electron microscopy, electrochemical impedance spectra, and transient photocurrent. It is shown that the prepared orthorhombic Bi2S3 has full-spectrum photoresponsivity. Bi2S3-B with 1D/2D heterogeneous structure exhibits the lowest charge carrier transport resistance, and its photocurrent intensity is nearly twice that of Bi2S3-C. It demonstrates the highest photocatalytic activity in visible-light photocatalytic reduction of aqueous Cr(VI), with a reduction rate of 54.5% after 140 minutes of light exposure. According to the bandgap of Bi2S3 and radical scavenger experiments, a reaction mechanism for the photocatalytic reduction of Cr(VI) by Bi2S3 was proposed. Furthermore, the results highlight the economic and environmentally friendly nature of the hydrothermal synthesis method using homemade precursors, which allows for the regulation of Bi2S3 morphology and the enhancement of its visible photocatalytic activity. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Organic pollutants entering water bodies lead to severe water pollution, posing a threat to human health. The activation of persulfate advanced oxidation processes using carbon materials derived from MOFs as substrates can efficiently treat wastewater contaminated with organic pollutants. This research uses NH2-MIL-101(Fe) as a substrate, doped with Fe2+ and Co2+, to prepare Fe/Co-CNs through a one-step carbonization method. The surface morphology, pore structure, and chemical composition of Fe/Co-CNs were investigated using characterization techniques such as XRD, SEM, TEM, XPS, FT-IR, BET, and Raman. A comparative study was conducted on the performance of catalysts with different Fe/Co ratios in activating PMS for the degradation of organic pollutants, as well as the effects of various influencing factors (the dosage of Fe/Co-CNs, the amount of peroxymonosulfate (PMS), the initial pH of the solution, the TC concentration, and inorganic anions) on the catalyst’s activation of persulfate for TC degradation. Through radical quenching experiments and post-degradation XPS analysis, the active radicals in the FeCo-CNs/PMS system were investigated to explain the possible mechanism of TC degradation in the Fe/Co-CNs/PMS system. The results indicate that Fe/Co-CNs-2 (with a Co2+ doping amount of 20%) achieves a degradation rate of 93.34% for TC (tetracycline hydrochloride) within 30 min when activating PMS, outperforming other Co2+ doping amounts. In addition, singlet oxygen (1O2) is the main reactive species in the reaction system.

In this study, undoped and Ni-doped ZnS nanoparticles were fabricated using a hydrothermal method to explore their structural, optical, and surface properties. X-ray diffraction (XRD) analysis confirmed the cubic crystal structure of ZnS, with the successful incorporation of Ni ions at various doping levels (2%, 4%, 6%, and 8%) without disrupting the overall lattice configuration. The average particle size for undoped ZnS was found to be 5.27 nm, while the Ni-doped samples exhibited sizes ranging from 5.45 nm to 5.83 nm, with the largest size observed at 6% Ni doping before a reduction at higher concentrations. Fourier-transform infrared (FTIR) spectroscopy identified characteristic Zn–S vibrational bands, with shifts indicating successful Ni incorporation into the ZnS lattice. UV–visible spectroscopy revealed a decrease in the optical band gap from 3.72 eV for undoped ZnS to 3.54 eV for 6% Ni-doped ZnS, demonstrating tunable optical properties due to Ni doping, which could enhance photocatalytic performance under visible light. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses confirmed the uniform distribution of Ni within the ZnS matrix, while X-ray photoelectron spectroscopy (XPS) provided further confirmation of the chemical states of the elements. Ni doping of ZnS nanoparticles alters the surface area and pore structure, optimizing the material’s textural properties for enhanced performance. These findings suggest that Ni-doped ZnS nanoparticles offer promising potential for applications in photocatalysis, optoelectronics, and other fields requiring specific band gap tuning and particle size control.

Rapid, inexpensive, and low-power/solar light-driven photocatalytic degradation of organic pollutants to deal with annually produced trillion tons of synthetic dye wastewater to prevent water scarcity issues, ecotoxicological risks, and human health has always been challenging. To overcome this limitation, the present study synthesized earth-abundant, inexpensive copper oxide nanosheets using a simple single-step hydrothermal route. The structural, physicochemical, and functional properties of the nanosheets have been characterized using several characterization techniques. The photocatalytic activity was studied for two commonly industrially used organic dyes, Methylene Blue (MB) and Rhodamine B (RhB). The importance of this work is the usage of a cheap commercially available Phillips UV light (11 W) as well as direct sunlight. With several optimized conditions, almost complete degradation of both dyes was achieved within 35 minutes under low-power UV light and within 70 minutes by the direct illumination of natural sunlight. The enhanced photocatalytic performance can be correlated to the synergetic effect of a higher charge transfer mechanism, good catalytic ‘active surface area’ availability (13.2 m2/g), and several optimized parameters that affect the reaction efficacy. Additionally, five repeated uses of nanosheets without sacrificing performance confirmed their stability and sustainability as a promising candidate for large-scale industrial textile wastewater remedies.

In this study, we conducted the hydrothermal synthesis of cobalt (Co)–doped NiWO4, resulting in the formation of Co–NiWO4 nanoparticles (NPs), followed by calcination at 550℃ for 12 h. Comprehensive analyses were performed to characterize the composition, structure, and morphology of the synthesized material. X-ray diffraction results confirmed the successful inclusion of Co in the NiWO4 lattice, with the presence of characteristic peaks of CoWO4. The crystallite size, determined using the Scherrer equation, was measured to be 22 nm. Using UV-Vis spectroscopy and Tauc’s equation, we calculated the band gap energy (E g) to be 3.75 eV for NiWO4 and 1.75 eV for Co–NiWO4. The potential application of the synthesized material as a photocatalyst was investigated for the degradation of the diazo dye Congo red (CR). Under optimized reaction conditions, Co–NiWO4 NPs demonstrated outstanding efficiency, degrading a total of 95% of CR. The degradation kinetics were well-described by the Langmuir–Hinshelwood (L–H) kinetic model, indicating that photoabsorption played a crucial role in the rate-controlling step. These encouraging results suggest that Co–NiWO4 NPs hold promise as a viable option for addressing other pollutants in various applications.

Zirconia (also known as zirconium dioxide, ZrO2) is a white crystalline naturally occurring mineral that offers excellent optical, dielectric, and mechanical properties. Considering these properties and referring to previous studies on the optimization of ZrO2 NPs synthesis, in the present study, we studied the crystalline, optical, and fluorescence properties of ZrO2 nanoparticles (NPs) formed by the hydrothermal synthesis route. The physicochemical features of the nanoparticles were examined in the photocatalytic oxidation of rhodamine B. From the powder XRD analysis, the ZrO2 NPs were found to be highly crystalline, while the fluorescence (FL) spectra indicated an emission band at 473 nm, which could be linked to a blue shift. Also, the FTIR and Raman spectroscopies confirmed the functionality and bonding, and in addition, the XPS analysis provided the elemental peaks of Zr 3d and O 1s, where all these analyses evidenced the successful formation of ZrO2. Examination of the photocatalytic activity of ZrO2 NPs revealed the capability of the material for rhodamine B photocatalytic degradation effectively, with a degradation efficiency of 86% after 2 h of treatment. Moreover, the nanoparticles exhibited stability and reusability over five cycles. Overall, from the analysis, ZrO2 NPs can be easily formed via the hydrothermal route with tailored optical and fluorescence properties to find applications in the electronics industry for the manufacturing of light emitting devices.

In recent years, cerium dioxide (CeO2) has attracted considerable attention owing to its remarkable performance in various applications, including photocatalysis, fuel cells, and catalysis. This study explores the effect of nickel (Ni) doping on the structural, thermal, and chemical properties of CeO2 nanorods, particularly focusing on oxygen vacancy-related phenomena. Utilizing X-ray powder diffraction (XRD), alterations in crystal structure and peak shifts were observed, indicating successful Ni doping and the formation of Ni2O3 at higher doping levels, likely due to non-equilibrium reactions. Thermal gravimetric analysis (TGA) revealed changes in oxygen release mechanisms, with increasing Ni doping resulting in the release of lattice oxygen at lower temperatures. Raman spectroscopy corroborated these findings by identifying characteristic peaks associated with oxygen vacancies, facilitating the assessment of Ni doping levels. Ni-doped CeO2 can catalyze the ultrasonic degradation of methylene blue, which has good application prospects for catalytic ultrasonic degradation of organic pollutants. Overall, this study underscores the substantial impact of Ni doping on CeO2 nanorods, shedding light on tailored catalytic applications through the modulation of oxygen vacancies while preserving the nanorod morphology.

The present study investigates the photocatalytic properties of hydrothermally synthesized TiO2 nanowires (NWs) for CO2 reduction in H2O vapor. It has been demonstrated that TiO2 NWs, thermally treated at 500–700 °C, demonstrate an almost tenfold higher yield of products compared to the known commercial powder TiO2 P25. It has been found that the best material is a combination of anatase, TiO2-B and rutile. The product yield increases with increasing heat treatment temperature of TiO2 NWs. This is associated with an increase in the degree of crystallinity of the material. It is shown that the best product yield of the CO2 reduction in H2O vapor is achieved when the TiO2 NW photocatalyst is heated to 100 °C.

In this work, β-NiS nanoparticles (NPs) were efficiently prepared by a straightforward hydrothermal process. The difference in morphology between these NiS NPs was produced by adding different amounts of thiourea, and the corresponding products were denoted as NiS-15 and NiS-5. Through electrochemical tests, the specific capacity (Cs) of NiS-15 was determined to be 638.34 C g−1 at 1 A g−1, compared to 558.17 C g−1 for NiS-5. To explore the practical application potential of such β-NiS NPs in supercapacitors, a hybrid supercapacitor (HSC) device was assembled with activated carbon (AC) as an anode. Benefitting from the high capacity of the NiS cathode and the large voltage window of the device, the NiS-15//AC HSC showed a high energy density (Ed) of 43.57 W h kg−1 at 936.92 W kg−1, and the NiS-5//AC HSC provided an inferior Ed of 37.89 W h kg−1 at 954.79 W kg−1. Both HSCs showed excellent cycling performance over 6000 cycles at 10 A g−1. The experimental findings suggest that both NiS-15 and NiS-5 in this study can serve as potential cathodes for high-performance supercapacitors. This current synthesis method is simple and can be extended to the preparation of other transition metal sulfide (TMS)-based electrode materials with exceptional electrochemical properties.

In this work, Ni3V2O8 (NVO) and Ni3V2O8-reduced graphene oxide (NVO-rGO) are synthesized hydrothermally, and their extensive structural, morphological, and electrochemical characterizations follow subsequently. The synthetic materials’ crystalline structure was confirmed by X-ray diffraction (XRD), and its unique marigold-like morphology was observed by field emission scanning electron microscopy (FESEM). The chemical states of the elements were investigated via X-ray photoelectron spectroscopy (XPS). Electrochemical impedance spectroscopy (EIS), Galvanostatic charge–discharge (GCD), and cyclic voltammetry (CV) were used to assess the electrochemical performance. A specific capacitance of 132 F/g, an energy density of 5.04 Wh/kg, and a power density of 187 W/kg were demonstrated by Ni3V2O8-rGO. Key electrochemical characteristics were b = 0.67; a transfer coefficient of 0.52; a standard rate constant of 6.07 × 10−5 cm/S; a diffusion coefficient of 5.27 × 10−8 cm2/S; and a series resistance of 1.65 Ω. By employing Ni3V2O8-rGO and activated carbon, an asymmetric supercapacitor with a specific capacitance of 7.85 F/g, an energy density of 3.52 Wh/kg, and a power density of 225 W/kg was achieved. The series resistance increased from 4.27 Ω to 6.63 Ω during cyclic stability tests, which showed 99% columbic efficiency and 87% energy retention. The potential of Ni3V2O8-rGO as a high-performance electrode material for supercapacitors is highlighted by these findings.

Zinc indihuhium sulfide (ZIS), among various semiconductor materials, shows considerable potential due to its simplicity, low cost, and environmental compatibility. However, the influence of precursor anions on ZIS properties remains unclear. In this study, we synthesized ZIS via a hydrothermal method using four different anionic precursors (ZnCl2/InCl3, Zn(NO3)2/In(NO3)3, Zn(CH3CO2)2/In(CH3CO2)3, and Zn(CH3CO2)2/In2(SO4)3), resulting in distinct morphologies and crystal structures. Our findings reveal that ZIS produced from Zn(CH3CO2)2/In2(SO4)3 (ZIS-AceSO4) exhibited the highest photocatalytic CO2 reduction efficiency, achieving a CO production yield of 134 μmol g−1h−1. This enhanced performance is attributed to the formation of more zinc and indium vacancy defects, as confirmed by EDS analysis. Additionally, we determined the energy levels of the valence band maximum (VBM) and the conduction band minimum (CBM) via UPS and absorption spectra, providing insights into the band alignment essential for photocatalytic processes. These findings not only deepen our understanding of the anionic precursor’s impact on ZIS properties but also offer new avenues for optimizing photocatalytic CO2 reduction, marking a significant advancement over previous studies.

In this study, we investigated the influence of pH on the hydrothermal synthesis of copper (II) oxide CuO nanostructures with the aim of tuning their morphology. By varying the pH of the reaction medium, we successfully produced CuO nanostructures with three distinct morphologies including nanoparticles, nanorods, and nanosheets according to the pH levels of 4, 7, and 12, respectively. The observed variations in surface morphology are attributed to fluctuations in growth rates across different crystal facets, which are influenced by the presence of intermediate species within the reaction. This report also compared the structural and optical properties of the synthesized CuO nanostructures and explored their potential for photoelectrochemical glucose sensing. Notably, CuO nanoparticles and nanorods displayed exceptional performance with calculated limits of detection of 0.69 nM and 0.61 nM, respectively. Both of these morphologies exhibited a linear response to glucose within their corresponding concentration ranges (3–20 nM and 20–150 nM). As a result, CuO nanorods appear to be a more favorable photoelectrochemical sensing method because of the large surface area as well as the lowest solution resistance in electroimpedance analysis compared to CuO nanoparticles and nanosheets forms. These findings strongly suggest the promising application of hydrothermal-synthesized CuO nanostructures for ultrasensitive photoelectrochemical glucose biosensors.

LaFeO3 thin films were successfully epitaxially grown on single-crystalline SrTiO3 substrates by the one-step hydrothermal method at a temperature of 320 °C in a 10 mol/L KOH aqueous solution using La(NO3)3 and Fe(NO3)3 as the raw materials. The growth of the films was consistent with the island growth mode. Scanning electronic microscopy, elemental mapping, and atomic force microscopy demonstrate that the LaFeO3 thin films cover the SrTiO3 substrate thoroughly. The film subjected to hydrothermal treatment for 4 h exhibits a relatively smooth surface, with an average surface roughness of 10.1 nm. X-ray diffraction in conventional Bragg–Brentano mode shows that the LaFeO3 thin films show the same out-of-plane orientation as that of the substrate (i.e., (001)LaFeO3||(001)SrTiO3). The in-plane orientation of the films was analyzed by φ-scanning, revealing that the orientational relationship is [001]LaFeO3||[001]SrTiO3. The ω-rocking curve indicates that the prepared LaFeO3 films are of high quality with no significant mosaic defects.

The addition of 2,5-pyridinedicarboxylic acid (2,5-PDCA) to the Mg-Al LDH coating, which was prepared by one-step hydrothermal synthesis, had extremely enhanced the corrosion protection of AZ31 Mg alloy, although the 2,5-PDCA could not be intercalated into the interlayer spacing. The corrosion current density of 0.05 mol L−1 2,5-PDCA LDH containing LDH coating is 3.18 nA cm−2, reduced by two orders of magnitude compared to the LDH coating without inhibitor, and the corrosion inhibition efficiency of the coating is 98.05%. The coating formed on the surface of AZ31 was peeled off from the substrate by using a mechanical method and SEM observation of the cross-section showed that the coating consisted of three different layers. The innermost layer is a thick layer that consists of Mg(OH)2 and the intermediate layer is LDH, which is vertical to the substrate and the outmost layer is a thin but very dense deposit layer of LDH agglomerates with complexes of 2,5-PDCA and Mg. This kind of sediment/LDH/Mg(OH)2 three-layer composite structure was accountable for the increase in the corrosion resistance of AZ31 Mg alloy.

The current study focuses the nanocomposites of Ag/WO3 was synthesized via hydrothermal method and extract of Aloe-vera gel was used. Various characterization techniques were used for the analysis of Ag/WO3 nanocomposites which includes SEM (scanning electron microscope), EDX (Energy dispersive spectroscopy), XRD (X-ray diffraction), FTIR (Fourier transform infrared), UV (ultraviolet–visible-spectroscopy) to tell about elemental composition, shape and crystalline structure, band gap, functional group. The presence of composition of elements O, W, Ag in Ag/WO3 nanocomposites was confirmed through EDX spectrum. The hexagonal crystal structure and the border peaks in Ag/WO3 nanocomposites were examined through XRD spectra. The Anti-oxidant activity was synthesized by using (DPPH) free Radical in Ag/WO3 nanocomposites. The outcomes of present study exhibited an excellent anti-oxidant activity and also indicated the reduction of stabilized free radical DPPH analysis using Aloe vera extract. The result revealed that the anti-oxidant activity of Ag/WO3 nanocomposites is essential for biomedical application and various industries.

In this work, two magnetite-biochar composite materials obtained via hydrothermal and co-precipitation methods to degrade dyes were evaluated. The two composite materials alongside their biochar precursor were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), Raman spectroscopy and N2 adsorption–desorption studies. Results of characterization showed a change in the amorphous structure of the biochar to a crystalline form after modification by both methods, the incorporation of magnetic particles into the carbonaceous matrix of the biochar precursor. In addition, the effect of solution pH, initial dye concentration H2O2 concentration, mass of composite material and the time of stirring on dye degradation were analysed by the response surface methodology. Both materials demonstrate appreciable stability over repeated cycles and more interestingly, Fe3O4-BC2 retains its catalytic efficiency much more than Fe3O4-BC1. Statistical analysis of the degradation results by ANOVA revealed a good correlation between the five parameters and the expected response with coefficients of correlation very close to unity. The degradation of reactive red-198 in the presence of both materials is best described by the second order kinetic rate law.

Calumnar basalt structure-based nanorods of Bi2S3 nanomaterial have been synthesized via hydrothermal processes. Through powder X-ray diffraction and Rietveld refinement analysis, the single phase and orthogonal structural nature of the Bi2S3 nanoparticle were confirmed, and the surface of the Bi2S3 nanoparticle was examined by a scanning electron microscope, which revealed that the nanoparticle has a pentagonal top surface and is a calumnar basalt nanorod type. For the measurement of the length and width of the nanorods, an image analysis tool has been employed, and the energy storage activities of this nanomaterial have been investigated by CV and GCD studies. It reveals that the specific capacitance of material through CV ranges from 3.20 to 5.28 farad /g, and concerning GCD it varies from 0.84 to 1.128 F/g Energy density 0.152–0.20 F/g V2, and the power density ranges from 109 to 1098 FV2/g. Stability attained at 0.237 volts and estimated capacitance 4.0117 mF identified with 0.8 R2 value from ESI study for this nanoparticle.

Researchers worldwide are working hard to develop nanoparticles that can be used for the photocatalytic degradation of dangerous substances and antibiotics. In this report, we present a study on how to make yttrium-incorporated magnesium oxide nanoparticles using hydrothermal and calcination methods. These particles measure around 50 nm and have excellent photocatalytic properties. We analyzed them using various physiochemical techniques like X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy with EDAX, transmission electron microscopy, X-ray photoelectron spectroscopy, and ultra-violet diffused reflectance spectroscopy. The nanohexagons created in this study showed reduced band gap energy from 4.8 eV to 3.8 eV when yttrium was incorporated into MgO nanohexagons resulting in an unusual increase in light absorption within the visible light region. Experimental reports show these synthesized nanoparticles could degrade about 66.5 % antibiotic Ciprofloxacin (CIP) and 79 % Methylene Blue (MB) dye respectively with .O2– playing a significant role at every step during the degradation process. This study demonstrates that these synthesized nanohexagons have practical applications as promising photocatalysts for treating toxic contaminants found in industrial effluents.

A microstructured cover flow mixer equipped with two cyclone structures was used for stable continuous hydrothermal synthesis of ZnO nanoparticles from Zn(NO3)2 and NaOH aqueous solutions in supercritical water. The effects of the NaOH/Zn(NO3)2 ratio, Zn(NO3)2 molality, and flow rate on Zn conversion, crystal structure, particle size, particle morphology, and mixer clogging were examined. The advantages of this mixer were identified by comparing with the results obtained using the same chemical conditions with tee-type, cross-type, and central collision-type mixers.

A thin film of polyvinylpyrrolidone (PVP) polymer doped with different weight ratios of magnesium oxide nanoparticles produced by using the low-temperature hydrothermal method was prepared, and the morphology of the doped thin film was verified using a scanning electron microscope and an atomic force microscope. The X-ray diffraction pattern showed that magnesium oxide has a multi cubic crystal structure with a diffraction peak of high density associated with the level (200) (at the diffraction angle of 42.69◦) and a crystal drop size of 25 nm. Measurements of the Fourier A transformation of the infrared spectrum of a polyvinylpyrrolidone polymer doped with metal oxides was carried out. It showed a clear difference from the pure polymer, where a (Mg-O-Mg) bond appeared at a wavelength of 450 cm^-1 to confirm the effect of MgO addition on the chemical bonding of polyvinylpyrrolidone. Optical properties, including absorbance, maximum wavelength, and energy gap, have been studied. Determined by ultraviolet examination. The band gap decreased when MgO was doped with PVP films, and the Hall coefficient effect was used to calculate the electrical properties, including the conductivity, kinetics of charge carriers, and their type. The highest conductivity was (0.1*10^-2 Sm), and the tainted membrane was of the n type), where it can be used in optical applications.

In the present study, single phase nickel based disulphide (NiS2) and diselenide (NiSe2) nanostructures were prepared hydrothermally in a short time span (4 h) under subcritical temperature (160 °C). The nanostructures grow in cubic crystal phases. Average crystallite sizes and intrinsic microstrains were determined using Williamson–Hall (W–H) plot analysis. Hollow NiS2 nanospheres and bipyramidal NiSe2 nanostructures are reported that are suitable for surface related applications. Thermal gravimetric analysis (TGA) indicated high stability of the nanostructures at elevated temperatures. Optical studies indicated visible light activeness of the nanostructures exhibiting sharp band edges. The nanostructures are mesoporous in nature with NiS2 and NiSe2 having respectively a large specific surface area of 310 m2/g and 177 m2/g. A primarily work done to determine the electrochemical nature of the nanostructures showed the materials are pseudo-capacitive in nature with specific capacitances of 1022 F/g and 480 F/g respectively for NiS2 and NiSe2. The photo-catalytic activity of the nanostructures was explored against a colourless pollutant; phenol. The nanostructures degraded most of the phenol (>90 %) under visible light illumination and the reusability experiments performed determined industrial value of the photocatalysts.

Electrocaloric cooling systems require components with large entropy change at the desired working temperature, high electric breakdown strength and low dielectric losses. We here report on hydrothermal synthesis (HTS) route for preparation of lead-free electrocaloric (EC) material Ba0.82Sr0.18Sn0.065Ti0.935O3 (BSSnT-18-6.5) with a median particle size of d50 = 150 nm. Influence of molar ratio (Ba,Sr):(Sn,Ti) on the purity and particle size of hydrothermally synthesized powders is investigated. The sintering behavior and the resulting microstructure of bulk ceramic samples prepared with HTS powders as well as their dielectric, ferroelectric, and electrocaloric properties are analyzed and discussed in detail. By using HTS powders we could significantly reduce sintering temperature from 1400 °C to 1275 °C. Samples prepared with a molar ratio (Ba,Sr):(Sn,Ti) of 1.6 show a maximum EC temperature change |ΔTEC| of 0.59 K around 30 °C with a broad peak of |ΔTEC| > 0.3 K in the temperature range from 5 °C to 65 °C under an applied electric field change of 5 V μm−1. Our results show that hydrothermal synthesis is well suited to produce starting powders of lead-free electrocaloric materials for future fabrication of multilayer ceramic (MLC) components.

In the pursuit of efficient, renewable, and cost-effective electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), a flower-like 1T phase molybdenum disulfide (1T-MoS2) was synthesized using an ambient plasma technique. With superior electrocatalytic activity and conductivity, it delivered a low Tafel slope of 74 mV/dec with the overpotential of -154 mV at the current density of -10 mA/cm2 for HER and improved Tafel slope of 94 mV/dec with overpotential of 216 mV at +10 mA/cm2 for OER. This study demonstrates the formation of 1T phase on the flower-like 2H-MoS2 by the easy ambient plasma method.

A new metal-organic hybrid complex [Cu(5,5′-dmbipy) (D-cam) (H2O)]n (1), (5,5′-dmbipy = 5,5′-dimethyl-2,2′-bipyridine, D-cam = D-camphoric acid anion) was hydrothermally synthesized. This complex was characterized by FTIR spectroscopy, TGA, and single-crystal X-ray diffraction. Crystallographic studies show that the title complex 1 crystallizes in an orthorhombic system with a P212121 space group with a = 06.9518(05) Ǻ, b = 13.5516(13) Ǻ, c = 22.6380(02)Ǻ; V = 2132.7(3) Ǻ3. The title CuII complex adopts a square pyramidal configuration. DFT study and Hirshfeld topology analysis of complex 1 was also done. The crystal achieves its three-dimensional structure and stability through polymeric chains having helical motifs of arrangement in between moieties and interconnected through hydrogen bonding interactions between the apical water molecule and non-coordinated oxygen atoms of the D-cam2- ligands. TGA, DFT calculations and Hirshfeld topology analysis revealed that the title complex 1 was stable.

Herein, we demonstrate the sample and low coast hydrothermal synthesis of a nanocomposite of Bi2O3/MoSe2 for hybrid photocatalyst. The structure of as-synthesized samples was characterized by using several techniques, including XRD spectroscopy, Raman spectroscopy, XPS, SEM, BET, and UV-visible absorption spectroscopy. The nitrogen adsorption–desorption measurements show that the samples have a mesoporous texture with slits like pores. The Bi2O3/MoSe2 nanocomposite had BET surface areas of 36.439 m2/g, which were more than those of Bi2O3 (18.342 m2/g) and MoSe2 (12.923 m2/g). Under visible illumination, the photocatalytic activities of pure samples ( Bi2O3 and MoSe2) and the hybrid Bi2O3/MoSe2 sample for the disintegration of methylene blue were assessed. The results show that the Bi2O3/MoSe2 sample showed the highest photocatalytic degradation efficiency (i.e. 96.5% after an exposure time of 80 min). The increased photocatalytic activity is due to the mixed sample's high crystallinity and surface area, as well as the small particle size.

Crystalline hematite nanoparticles as adsorbents for anionic Congo red dye were prepared by a hydrothermal process using urea hydrolysis. To examine the effects of coexisting anions in a solution on the formation of hematite nanoparticles, different iron(III) salts, including iron chloride hexahydrate, iron nitrate nonahydrate, iron sulfate n-hydrate, ammonium iron sulfate dodecahydrate, and basic ferric acetate, were employed as iron-ion sources. After the hydrothermal treatment of the solution, consisting of an iron salt and urea at 423 K for 20 h, a single phase of hematite was formed from the iron-nitrate solution. The results suggested that the hydrothermal formation of hematite depended on the stability of iron complexes formed in the starting solution. The average crystallite size and median diameter of hematite nanoparticles also depended on the coexisting anions, suggesting that the appropriate selection of the coexisting anions in the starting solution can allow for control of the crystallite size and particle diameter of hematite nanoparticles. The Congo red adsorption kinetics and isotherms of the hematite nanoparticles were described by the Elovich model and Langmuir model, respectively. The adsorption thermodynamics parameters were estimated, which suggested an exothermic and spontaneous process. The results demonstrated good adsorption properties for Congo red adsorption.

Layered silicates with a montmorillonite structure are widely used in various fields related to adsorption, gas and water treatment, catalysis, cosmetology and medicine. Under conditions of directed hydrothermal synthesis, montmorillonites with the specified characteristics can be obtained. The influence of the preparation method for montmorillonites of two compositions (Mg3Si4O10(OH)2 H2O and Na1.5Al0.5Mg1.5Si4O10(OH)2 H2O) on their sorption properties, moisture absorption, porous textural characteristics and surface properties has been studied. The nature of the initial reagents, the pH of the reaction medium and the synthesis temperature were chosen as the variable synthesis parameters. It has been established that the synthesis conditions significantly affect the properties of montmorillonite, which, in turn, determines the possibilities of using the materials obtained in specific areas.

It is well known that sulfonamide derivatives, through exchange of different functional groups without modification of the –S(O)2N(H)– function, can exhibit a wide variety of pharmacological activities. In addition, some metal complexes of these ligands have been prepared to promote rapid healing of burns in humans and animals, for example, the complex of Zn(ii) sulfadiazine. Their effectiveness does not depend solely on the slow release of the metal ion, but rather strongly on the nature of the material to which the metal is bound. Given the ability of sulfonamide derivatives to coordinate with metal atoms in different ways, considerable interest in the synthesis and structural aspects of new complexes has arisen. These results confirm that the significant chemical capacity of sulfonamides to act as ligands is based on the acidity of its –S(O)2N(H)– function, which gives a donor anionic ligand, allied to the presence of atoms vicinal to nitrogen, sulfur or oxygen of the heterocyclic ring, which provide the stereochemical requirements for the realization of complexes with monodentate ligand, chelating agent or bridging ligand, providing monomeric structures, dimeric arrangements and polymers. In addition, the aromatic amino group is responsible for the chemical versatility of the sulfonamides, since it can act as a coordination site, as well as a reactive site for chemical modifications of sulfonamide complexes with very interesting biological purposes. In the present work, the synthesis and structure of a novel sulfanilamide complex: nitro (4-aminobenzenesulfonamide) zirconium was presented. Characterization of the complex was performed by infrared spectroscopic, thermogravimetric and X-ray diffraction analysis.

In this study, we describe a facile hydrothermal method for synthesis of carbon nano-arrays, using materials available locally, resulting in an affordable autoclave system. Stainless steel type 1.4401 (with grade 316) possesses high temperature mechanical properties and anticorrosion characteristics and is therefore appropriate for autoclave device construction. For analysis, a systematic study of the three Von Misses stress models of an autoclave system was performed using Abaqus software. Also, the effect of the component's thickness on the stress concentration was examined. This was done to find the most optimal mode of the autoclave's resistance to stress caused by temperature and pressure. So, for further evaluation of this reactor in the laboratory, a series of experiments was designed. It is interesting to find that natural potato and chemical starch as low-cost precursors play a vital role in constructing carbon-based nanomaterials. In this study, by utilizing natural extracts and chemical precursors, the potential of designed autoclave systems has been explored in the fabrication of carbon materials with diverse shapes of nanorods and nanospheres. The structural, chemical compositional and morphological changes of the products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) analyses. As the precursor was changed, a significant difference was observed in the shape and morphologies of the black nano-products. Such results suggest competition between designed and commercial autoclaves in the fabrication of nanomaterials. More importantly, these structure-controlled carbon nanomaterials with unique properties can be explored in many practical applications.