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Nanoparticles of spinel ferrites with a composition of Co0.9Cu0.1Fe2O4 (AM NPs) were effectively synthesized via a hydrothermal route. The structure of ferrite nanoparticles was characterized with X-ray diffraction, which showed a single cubic spinel phase. Energy-dispersive X-ray (EDX) spectroscopy and field emission-scanning electron microscopy (FE-SEM) were employed to analyse elemental composition and surface morphology, respectively. Moreover, the effects of the Co0.9Cu0.1Fe2O4 on the morphology of [PLA = polylactic acid] nanocomposites were examined through polarized light optical microscopy (POM) and X-ray diffraction (XRD). The thermal behaviours for tested samples were studied through [DSC = differential scanning calorimetry] and [TGA = thermal gravimetric analysis]. A great number of minor PLA spherulites were detected using POM in the presence of the Co0.9Cu0.1Fe2O4 ceramic magnetic nanoparticles (AM), increasing with AM nanoparticle contents. X-ray diffraction (XRD) analysis showed that the presence of nanoparticles led to an increase in the intensity of diffraction peaks. The DSC findings implied that the crystallization behaviours for the efficient PLA as well as its nanocomposites were affected by the addition of AM nanoparticles. They act as efficient nucleating agents because they shift the temperature of crystallization to a lower value. The Avrami models were used to analyse kinetics data. The experimental data were well described using the Avrami method for all samples tested. The addition of AM to the PLA matrix resulted in a decrease in the crystallization half-time t1/2 values, indicating a faster crystallization rate. TGA data showed that the occurrence of AM nanoparticles decreased the thermal stability of PLA. [ABSTRACT FROM AUTHOR]

This current study assessed the impacts of morphology adjustment of perovskite BiFeO3 (BFO) on the construction and photocatalytic activity of P-infused g-C3N4/U-BiFeO3 (U-BFO/PCN) heterostructured composite photocatalysts. Favorable formation of U-BFO/PCN composites was attained via urea-aided morphology-controlled hydrothermal synthesis of BFO followed by solvosonication-mediated fusion with already synthesized P-g-C3N4 to form U-BFO/PCN composites. The prepared bare and composite photocatalysts' morphological, textural, structural, optical, and photocatalytic performance were meticulously examined through various analytical characterization techniques and photodegradation of aqueous rhodamine B (RhB). Ellipsoids and flakes morphological structures were obtained for U-BFO and BFO, and their effects on the successful fabrication of the heterojunctions were also established. The U-BFO/PCN composite exhibits 99.2% efficiency within 20 min of visible-light irradiation, surpassing BFO/PCN (88.5%), PCN (66.8%), and U-BFO (26.1%). The pseudo-first-order kinetics of U-BFO/PCN composites is 2.41 × 10−1 min−1, equivalent to 2.2 times, 57 times, and 4.3 times of BFO/PCN (1.08 × 10−1 min−1), U-BFO, (4.20 × 10−3 min−1), and PCN, (5.60 × 10−2 min−1), respectively. The recyclability test demonstrates an outstanding photostability for U-BFO/PCN after four cyclic runs. This improved photocatalytic activity exhibited by the composites can be attributed to enhanced visible-light utilization and additional accessible active sites due to surface and electronic band modification of CN via P-doping and effective charge separation achieved via successful composites formation. [ABSTRACT FROM AUTHOR]

Design of experiments is a powerful planning technique that optimizes processes and reduces experimental variability. This research aims to optimize the hydrothermal synthesis of TiO2 nanotubes with a high specific surface area (SSA). A 22 factorial design was applied to investigate the influence of temperature and time on nanotube formation, achieving SSA above 350 m2 g−1. A Doehlert design combining SSA with morphology reveals closely related responses and a defined maximum surface. Microscopy shows that nanotube formation is favored at lower temperatures and longer treatment times, with the optimal condition at 120 °C for 36 h. Higher temperatures yield cauliflower-like nanostructures and provide insight into how synthesis conditions affect the morphology and nanoparticle properties. XRD and Raman spectroscopy analysis revealed that, although the anatase phase played a vital role in nanotube formation, the materials exhibited a combination of crystalline phases, including the discovery of an unidentified phase. [ABSTRACT FROM AUTHOR]

Simple hydrothermal method can be applied for synthesizing rod shape Gd2O3:Eu3+ phosphors. X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscopy are used for the characterizations of samples. Increase of Eu3+ concentration in Gd2O3:Eu3+ can cause red shift in the charge transfer band (CTB) of Eu – O. The nature of Eu3+ surroundings is asymmetric. It is ascertained from PL emission studies. The calculation of second order crystal field parameter from PL spectra corroborates the asymmetric environment of Eu3+. PL emission and decay lifetime studies confirm the existence of quenching due cross-relaxation. The quantum yield for Y2O3:Eu3+ (19 at.%) under 265 nm excitation is found to be 7%. [ABSTRACT FROM AUTHOR]

We report on Ru-doped self-supported honeycomb nickel molybdate nanoflakes (Ru-NiMoO 4 /NF) with abundant OV on Ni foam and its application in both electrocatalytic NO 2 –RR and Zn-NO 2 – battery. The catalytic activity of Ru-NiMoO 4 /NF was significantly enhanced due to the Ru doping and the existence of oxygen vacancies, achieving high Faraday efficiency of 95.56 ± 0.72% and large ammonia yield of 17192.52 ± 1136.64 μg h−1 cm−2 at –0.6V vs. RHE in 0.5 M Na 2 SO 4 and 0.1 M NO 2 – solution, as well as preferable long-term stability. In addition, it was verified that Zn-NO 2 – battery with Ru-NiMoO 4 /NF as cathode delivers a good energy supply (13.87 mW cm−2), as well as simultaneously ammonium yield of 1524.74 μg h−1 cm−2 and Faradaic efficiency of 96.15% at 15 mA cm−2. [Display omitted] The electrocatalytic reduction of nitrite to recyclable ammonia (NH 3) is essential to maintain nitrogen balance and meet growing energy requirements. Herein, we report that Ru doped honeycomb NiMoO 4 nanosheet with copious oxygen vacancies grown on nickel foam substrate has been prepared by a facile hydrothermal synthesis and immersion process, which can act as an efficient electrocatalyst for NH 3 synthesis by reduction of nitrite. By optimizing the concentration of RuCl 3 solution, 0.01Ru-NiMoO 4 /NF possesses excellent NO 2 −RR performance with NH 3 yield of 20249.17 ± 637.42 μg h−1 cm−2 at −0.7 V and FE of 95.56 ± 0.72 % at −0.6 V. When assembled into a Zn–NO 2 − battery, it provides a remarkable level of power density of 13.89 mW cm−2, outperforming the performance of virtually all previous reports. The efficient adsorption and activation of NO 2 − over Ru-doped NiMoO 4 with oxygen vacancy have been verified by density functional theory calculations, as well as the possible reaction pathway. [ABSTRACT FROM AUTHOR]

Usage of cost effective synthesis methods are inevitable due to increasing economic conditions worldwide. In this study, zinc oxide nano-structures were synthesized by low cost chemical methods. Outcomes of X-ray diffraction analysis revealed dominating plane was c-axis for ZnO seed layer and nano-rods deposited by sol–gel spin coating and chemical bath deposition method (CBD), respectively. However, a-axis plane dominance was observed for ZnO nano-rods prepared by hydrothermal method. Scanning electron microscopy offered the surface morphology of granular structure and well aligned compact ZnO nano-rods by sol–gel and CBD, respectively. Conversely, randomly oriented ZnO nano-rods were found by hydrothermal method. Presence of zinc and oxygen in the samples was confirmed by EDS results. Optical band gap of 3.29 eV, 3.25 eV and 3.21 eV were obtained by sol–gel, CBD and hydrothermal method, respectively. Likewise, photoluminescence results were also analyzed for all the samples. The super-hydrophobic state with water contact angle (WCA) of 150° was observed for ZnO nano-rods by CBD. However, hydrophilic and hydrophobic state was detected for ZnO seed layer and nano-rods with WCA of 70° and 118°, respectively. The super-hydrophilic state was also noticed after the induction of Ultra-Violet (UV) light. The WCA reduction rate of the values 0.067 and 0.17 were estimated for ZnO nano-rods. Furthermore, CA recovery time was also measured. The UV sensing photo-response was evaluated among seed layer and nano-rods, and better result was produced by ZnO nano-rods by CBD. [ABSTRACT FROM AUTHOR]

In this work, distinct-morphological Co 3 O 4 /Nickel foams were prepared through a simple hydrothermal method and a subsequent heat treatment process. The morphology of Co 3 O 4 can be efficiently modulated from hexagonal nanosheets to nanobunches and urchin-like microspheres by manipulating the NH 4 F concentration. For the urchin-like Co 3 O 4 /Nickel foam composites, the minimum reflection loss (RL min) value can reach −42.53 dB at a matching thickness of 2.7 mm. Theoretical analysis shows that the enhanced microwave absorption intensity is mainly originated from dielectric losses including significant interfacial polarization of the abundant interfaces, intrinsic dipoles of Co 3 O 4 and magnetic losses containing natural resonance and eddy current loss are favorable for the impedance matching. Simultaneously, multiple scattering occurring within the 3D Ni network skeleton are considered to promote the microwave absorption performance. Furthermore, a quadrilateral cone array of the resultant urchin-like Co 3 O 4 /Nickel foam composites has a RL min of −56.7 dB and an effective absorption bandwidth can achieve 9.44 GHz. This work could be beneficial for exploiting high-efficient magnetic-dielectric microwave absorption materials via the microstructural design. [ABSTRACT FROM AUTHOR]

Metallogenic models of polyphase mountain belts critically rely on robust geochronology. We combine petrology with Rb--Sr and U--Th--Pb in situ geochronology, paired at thin-section scale, to date mineralization in deformed hydrothermal Pb--Zn--Ag deposits along an east-west transect in the Western Alps, France. The Pb--Zn--Ag veins occur in shear zones with kinematic structures consistent with the mylonitized host rocks. The ore consists mainly of galena in a quartz-phengite gangue. The paragenesis can be related to hydrothermal crystallization during periods of variable strain. Both isotope systems yield only Cenozoic ages (ca. 35 Ma and 15-20 Ma) without any pre-Alpine inheritance, clearly indicating orogenic mineralization. The metallogenic model proposed here includes significant fluid circulation along major tectonic contacts between basement and sedimentary cover during Alpine convergence. [ABSTRACT FROM AUTHOR]

The study of lubricating oil is paramount for the optimal functioning of modern engines, and it has generated intensive research in the automotive industry. The aim is to improve the tribological properties of lubricants by including nanomaterials as additives in base oils. This article presents an exhaustive bibliographic review of the experiments carried out to optimize the tribological properties of nano-lubricants in order to identify the nanoparticles and experimental processes used and analyze the results obtained. The methodology adopted combines inductive and deductive elements. It begins with the formulation of a general theory on the application of nanoparticles in lubricants, followed by the collection of specific data on the conceptualization and preparation of nano-lubricants. A total of 176 articles focused on the application of nanoparticles in lubricants, especially to reduce the coefficient of friction, are reviewed. These works, with impact levels Q1 and Q2, delve into the application and are analyzed to review the obtained results. Most researchers worked with a nanoparticle concentration range of 0% to 1% by volume. [ABSTRACT FROM AUTHOR]

The present study utilized zinc-tin nanoflowers (ZT-NFs) in a batch adsorption treatment process to effectively remove cadmium from synthetic wastewater. The batch adsorption strategy was optimized using the univariate approach to enhance the efficiency of the adsorption process. The dominant parameters examined in the optimization experiments were pH/volume of buffer solution, nanoflower amount, and sample agitation type/period. After determining the optimal batch adsorption conditions, equilibrium studies were performed by adding cadmium to synthetic wastewater at concentrations in the range of 1.0 – 40 mg/L. The quantification accuracy for cadmium was improved by developing the calibration plot with spiked sample matrix. The equilibrium data were subjected to mathematical modelling utilizing the Langmuir adsorption isotherm model. The calculated isotherm constants indicated a well-fitted isotherm model to the experimental data. The reported ZT-NFs-based adsorptive removal strategy was effectively employed to remove cadmium from synthetic wastewater. [ABSTRACT FROM AUTHOR]

Utilizing Aloe vera gel (AVG) extracts as reducing agents, the hydrothermal synthesis of dual-functional iron oxide nanoparticles (Fe2O3 NPs) offers a straightforward and environmentally friendly approach. AVG extract, rich in polyphenol complexes and antimicrobial compounds, serves both as a reducing agent for ferric chloride in aqueous solutions and as a stabilizing agent for the resulting nanoparticles. This method showcases the potential of natural plant biomolecules in nanoparticle synthesis. UV–Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), vibrating sample magnetometry (VSM) and energy dispersive X-ray spectroscopy (EDX) were used to characterise the Aloe vera gel –Fe2O3 nanoparticles (AVGF NPs). The pattern on the XRD indicated the production of crystalline material, which matched JCPDS card no. 89–0596 precisely. Nondestructive XRD analysis indicated a rhombohedral phase crystalline structure, whereas scanning electron microscopy revealed a spherical form. Surface morphology images exhibited that the NPs have sphere-shaped with a size in the range 10–40 nm and magnetic measurements is a high saturation magnetization value of 73.9 emu were synthesised. Bragg's reflection speaks indicated that the rhombohedral phase structure of AVGF NPs. The thermal stability and functional groups analysis results indicated that the presence of the AVG on the Fe2O3 surface. Moreover, the AVGF NPs had different coloring reflectance on the solution to confirm by absorption spectra. These findings suggest that the formation of AVGF NPs in producing great stable, fluorescence lifetime (26.21 ns), more lasting magnetic characteristics ideal for a variety scenarios primarily effective antimicrobial properties against Gram-positive bacteria and potential conversion of hazardous Cr6+ to less harmful Cr3+ and promising AVGF catalyst efficacy for methylene blue discoloration. [ABSTRACT FROM AUTHOR]

This study presents the use of a low-temperature hydrothermal method for extracting calcium sources from green mussel shell (P. Viridis) wastes and converting them into synthetic nanosized hydroxyapatite (HA). In this study, raw mussel shells were washed, pulverised, and sieved to start producing a fine calcium carbonate-rich powder. XRD quantitative analysis confirmed that the powder contains 97.6 wt. % aragonite. This powder was then calcined for 5 h at 900 °C to remove water, salt, and mud, yielding a calcium-rich feedstock with major minerals of calcite (68.7 wt.%), portlandite (24.7 wt.%), and minor aragonite (6.5 wt.%). The calcined powders were dissolved in aqueous stock solutions of HNO3 and NH4OH before hydrothermally reacting with phosphoric acid [(NH4)2HPO4], yielding pure, nanoscale (16-18 nm) carbonated HA crystals, according to XRD, FT-IR, and SEM analyses. The use of a low-temperature hydrothermal method for a feedstock powder produced by the calcination of low-cost mussel shell wastes would be a valuable processing approach for the industry's development of large-scale hydroxyapatite nanoparticle production. [ABSTRACT FROM AUTHOR]

Giant Nb deposits hosted by alkaline igneous rocks worldwide are characterized by hydrothermal and/or metamorphic modifications after magmatic crystallization. However, the impact of secondary processes on Nb mineralization in alkaline igneous rocks remains controversial. In this study, U–Pb ages, elemental, and Nd isotope compositions of titanite from a series of Nb-rich dyke swarms in the Ziyang region of South Qinling (China) have been investigated to unveil Nb remobilization and enrichment histories during magmatic and hydrothermal processes. Three types of titanite are documented: magmatic, deuteric, and hydrothermal. The magmatic titanite (Ttn I) grains are euhedral wedge-shaped, while the deuteric type (Ttn II) occurs as coronas on magmatic ilmenite. The hydrothermal titanite (Ttn III) occurs as either bead-like clusters within the cleavage planes of chloritized biotite or as anhedral grains (lesser than 200 μm in diameter) coexisting with hydrothermal actinolite, chlorite, fluorite, and/or REE-rich oxides. The magmatic titanite grains from the most primitive igneous rocks have U–Pb ages of 455 ± 25 Ma and are characterized by high levels of Nb2O5 (up to 1.4 wt%) and other high field strength elements (HFSE, up to 1.3 wt% ZrO2), rare earth elements (REE), and V, and high mean crystallization temperatures (880 ± 40 °C), suggesting that they nucleated and crystallized in a high-T and Nb-rich alkaline magma during the Early Paleozoic. The gradual decrease in V, Sr, and Ba in Ttn I from mafic to intermediate dykes exemplifies the role of fractionation on magmatic enrichment of Nb (mean of 170 ppm and 7300 ppm for Ttn I in mafic and intermediate dykes, respectively) and other incompatible elements (e.g., Ta, Zr, Hf, Sn, Y, and REE) in the residual melt. The deuteric and hydrothermal types of titanites in each lithology have lower concentrations of HFSE (e.g., Nb mean of 140 ppm and 860 ppm for Ttn II in mafic and intermediate dykes, respectively), Sn, LREE, and Y but higher Al, F, V, Sr, and HREE contents than their magmatic counterpart. The deuteric and hydrothermal types of titanite have U–Pb ages of 420 ± 25 Ma and 232 ± 49 Ma, respectively, supporting two distinct hydrothermal events at Ziyang. The magmatic and deuteric types of titanite have similar ranges of εNd(t) values (+ 1.4 to + 3.5 and + 2 to + 4.2, respectively), indicative of a common source for these two generations. The hydrothermal titanite also has comparable εNd(t) values (+ 0.8 to + 2.7) to the magmatic and deuteric types, indicating a minimal external contribution to Nd (and by analogy Nb as well) from the late hydrothermal fluids. The deuteric and late hydrothermal F-rich fluids in Ziyang dyke swarms both remobilized the dispersed Nb in magmatic ilmenite, amphibole, and biotite to form secondary titanite (Ttn II, III), which is beneficial to the metallurgical extraction of this critical metal. Therefore, both magmatic fractional crystallization and hydrothermal remobilization contributed to Nb mineralization. [ABSTRACT FROM AUTHOR]

Titanates are one of promising sorbents for toxic heavy metal ions and radionuclides due to various chemical formulas and crystal structures, and their functional properties. Herein, we present a unique seaweed-like sodium titanate mat (SST) with randomly distributed layered sodium dititanate nanofibers synthesized by a simple hydrothermal process. We focused on the effect of NaOH concentration during the hydrothermal process on crystallographic properties and investigated the synthesis conditions for SST. Furthermore, Sr2+ sorption properties of SST and related titanates, which were synthesized by hydrothermal process, was studied by batch tests. SST, which consist of a dititanate phase, was synthesized at 10 mol/L NaOH concentration and trititanate phase was formed when the NaOH concentration was increased to 15 mol/L. The SST showed a high ion-exchange selectivity of Sr2+ against H+ and a high maximum sorption capacity (2 mmol/g), compared with the case of trititanate phase (0.49 mmol/g), which shows the precipitation of SrCO3. This was presumably due to the difference of crystal structure of two titanates. This study demonstrates that the design of the crystal structure is important for controlling the sorption mechanism of sorbents for water treatment. [ABSTRACT FROM AUTHOR]

Proton-exchange-membrane hydrogen fuel cells (PEMFCs) are an important energy device for achieving a sustainable hydrogen society. Carbon-based catalysts used in PEMFCs' cathode can degrade significantly during operation-voltage shifts due to the carbon deterioration. The longer lifetime of the system is necessary for the further wide commercialization of PEMFCs. Therefore, carbon-free catalysts are required for PEMFCs. In this study, highly crystallized conducting Sb-doped SnO2 (Sb-SnO2) nanoparticles (smaller than 7 nm in size) were synthesized using an ozone-assisted hydrothermal synthesis. Pt nanoparticles were loaded on Sb-SnO2 supporting particles by polyol method to be "Pt/Sb-SnO2 catalyst". The Pt/Sb-SnO2 catalyst showed a high oxygen reduction reaction (ORR) mass activity (178.3 A g−1-Pt @ 0.9 V), compared to Pt/C (149.3 A g−1-Pt @ 0.9 V). In addition, the retention ratio from the initial value of electrochemical surface area (ECSA) during 100,000-voltage cycles tests between 1.0 V and 1.5 V, Pt/SnO2 and Pt/Sb-SnO2 catalyst exhibited higher stability (90% and 80%), respectively, than that of Pt/C catalyst (47%). Therefore, the SnO2 and Sb-SnO2 nanoparticles synthesized using this new ozone-assisted hydrothermal method are promising as carbon-free catalyst supports for PEMFCs. [ABSTRACT FROM AUTHOR]

This article is devoted to the study of the effect of ZnO nanoparticles on the development of tolerance to salt stress in rye samples. As a quantitative criterion for assessing the degree of oxidative stress, the amount of H2O2 released in the samples during growth was determined. For these purposes, an electrochemical sensor based on hydrothermally synthesized wall-shaped NiO nanostructures was developed. This sensor has been proven to demonstrate high sensitivity (2474 µA·mM−1), a low limit of detection (1.59 µM), good selectivity against common interferents, and excellent long-term stability. The investigation reveals that the incorporation of ZnO nanoparticles in irrigation water notably enhances rye's ability to combat salt stress, resulting in a decrease in detected H2O2 levels (up to 70%), coupled with beneficial effects on morphological traits and photosynthetic rates. [ABSTRACT FROM AUTHOR]

The present work involves the design and validation of an electrochemical sensor for precise and selective sensing of nicotinamide adenine dinucleotide (NADH). The designed electrochemical sensor consists of TCNQ and Pd-Co@NC nanocomposite–modified electrodes (TCNQ-Pd-Co@NC/CPE). The designed electrode was validated by cyclic voltammetry, amperometry, and electrochemical impedance spectroscopy (EIS). The results revealed potent electrocatalytic activity towards NADH oxidation and sensing. Cyclic voltammetry revealed the superior capability of TCNQ-Pd-Co@NC-based carbon paste electrode in electron transfer than TCNQ-Co@NC/CPE and TCNQ/CPE, validating better conductivity of TCNQ-Pd-Co@NC/CPE for NADH sensing. Amperometry study provided a wide linear range of 10 to 250 µM for NADH detection with a low detection limit (LOD) of 5.17 µM and a sensitivity of 21.5 µA mM. EIS study revealed the lowest Rct value of 12.5 × 102 for TCNQ-Pd-Co@NC/CPE compared to TCNQ-Co@NC/CPE and TCNQ/CPE, demonstrating high electron transfer capability and thus sensitivity towards NADH. Besides this, the modified TCNQ-Pd-Co@NC-based carbon paste electrodes offered exceptional selectivity, reproducibility, and stability over time. Therefore, designed TCNQ-Pd-Co@NC nanocomposite–based carbon paste electrodes can be efficiently used for precise and selective NADH sensing. [ABSTRACT FROM AUTHOR]

Chiral surfaces are an object of interest due to their application in catalysis, separation and sensors. Such surfaces can exhibit chirality on the molecular or supramolecular level. Previously, we have studied the thermodynamic features of adsorption on non-porous surfaces with supramolecular chirality. However, for their application in enantiomer separation, enantioselectivity and capacity should be greater. Porous adsorbents are promising for this purpose. In this work, the enantioselectivity of copper borophosphate LiCu2[BP2O8(OH)2] was studied. This zeotype material was obtained by hydrothermal synthesis without any source of chirality. Supramolecular chirality was achieved by spontaneous symmetry breaking via Viedma ripening. XRD and SEM were used to prove the synthesis accuracy. Enantioselectivity during adsorption was studied using the adsorption isotherms of α-pinene and limonene enantiomer analysis. The experimental isotherms were approximated by Langmuir, Dubinin–Radushkevich, Freundlich and Fowler–Guggenheim equations. The t-test was used to prove the reliability of the differences in enantiomer adsorption. The isosteric heats of adsorption were calculated from the adsorption isotherms. The data obtained have shown the ability of the LiCu2[BP2O8(OH)2] surface to recognize both α-pinene and limonene enantiomers. The molecules of α-pinenes adsorbed without pores, with the maximum enantioselectivity coefficient of 1.23 at 80 °C. Limonene molecules adsorbed in pore volume as single molecules or 1D chains. This phenomenon was proved by analysis of isosteric heats. The enantioselectivity of copper borophosphate to limonenes and α-pinenes was similar. The ability of pores with supramolecular chirality (and without molecular chirality) to recognize enantiomers was discovered in this paper for the first time. [ABSTRACT FROM AUTHOR]

Zeolites are a class of catalysts with specific pore structures as well as different pore sizes, which are now widely used in various shape-selective catalytic reactions. In this paper, a uniform micro/mesoporous core–shell composite HZSM-@MCM-41 comprising zeolite was successfully prepared by coating mesoporous MCM-41 shells on nanosized ZSM-5 cores using a two-step hydrothermal method. Nanoscale ZSM-5 cores with different acidity were successfully prepared by changing the Si/Al of the initial solution of pristine ZSM-5, and three different thicknesses of MCM-41 shell layers were easily encapsulated on the surface of ZSM-5 with different acidity by varying the amount of silicon source added in the secondary hydrothermal crystallization process. The synthesized series of micro-mesoporous core–shell catalysts were also applied to the catalytic fast pyrolysis in lignin. In the catalytic fast pyrolysis of lignin, the mesoporous structure promoted the transition of biomass pyrolysis intermediate to liquid products, and the acidity of the HZSM-5 core facilitated their catalytic transformation to aromatic hydrocarbons. Among all the tested catalysts, the HZ@M-80-ll catalyst with an internal Si/Al = 80 and MCM-41 shell thickness of ∼25 nm exhibited the highest production of light aromatics and phenols. [ABSTRACT FROM AUTHOR]

Chiral surfaces are an object of interest due to their application in catalysis, separation and sensors. Such surfaces can exhibit chirality on the molecular or supramolecular level. Previously, we have studied the thermodynamic features of adsorption on non-porous surfaces with supramolecular chirality. However, for their application in enantiomer separation, enantioselectivity and capacity should be greater. Porous adsorbents are promising for this purpose. In this work, the enantioselectivity of copper borophosphate LiCu2[BP2O8(OH)2] was studied. This zeotype material was obtained by hydrothermal synthesis without any source of chirality. Supramolecular chirality was achieved by spontaneous symmetry breaking via Viedma ripening. XRD and SEM were used to prove the synthesis accuracy. Enantioselectivity during adsorption was studied using the adsorption isotherms of α-pinene and limonene enantiomer analysis. The experimental isotherms were approximated by Langmuir, Dubinin–Radushkevich, Freundlich and Fowler–Guggenheim equations. The t-test was used to prove the reliability of the differences in enantiomer adsorption. The isosteric heats of adsorption were calculated from the adsorption isotherms. The data obtained have shown the ability of the LiCu2[BP2O8(OH)2] surface to recognize both α-pinene and limonene enantiomers. The molecules of α-pinenes adsorbed without pores, with the maximum enantioselectivity coefficient of 1.23 at 80 °C. Limonene molecules adsorbed in pore volume as single molecules or 1D chains. This phenomenon was proved by analysis of isosteric heats. The enantioselectivity of copper borophosphate to limonenes and α-pinenes was similar. The ability of pores with supramolecular chirality (and without molecular chirality) to recognize enantiomers was discovered in this paper for the first time. [ABSTRACT FROM AUTHOR]

Hydrogen holds great promise in the pursuit of decarbonizing energy systems. One of the key processes in hydrogen production is the hydrogen evolution reaction (HER), which relies on efficient catalysts. Cobalt sulfide (CoS) has attracted significant attention owing to its exceptional catalytic activity for HER. However, it suffers from low intrinsic catalytic activity. In this study, we aimed to enhance the catalytic activity of CoS materials for HER by fabricating cobalt sulfide on Ni foam (NF@CoS) through hydrothermal synthesis and applying surface modification techniques such as plasma treatment. Various gases, including H2, O2, N2, and Ar, were used to subject CoS to plasma treatment. The results demonstrated that the optimal sample, named AP-NF@CoS, obtained through Ar plasma treatment, exhibited the lowest overpotential of 133 mV at a current density of 50 mA cm–2. Furthermore, the AP-NF@CoS sample displayed excellent performance, with a Tafel slope of 129 mV dec–1. These findings indicate that plasma treatment on NF@CoS is an effective method for producing high-performance electrocatalysts for the HER. [ABSTRACT FROM AUTHOR]

Hydroxyapatite is a biocompatible material with various applications. To meet the demand for industrial use of this material, a rapid and upscalable process for the synthesis of hydroxyapatite nanoparticles was developed using an in-house developed two-stage continuous flow hydrothermal reactor. In the framework of this study, phase pure and highly crystalline 30 to 115 nm long hydroxyapatite nanorods were produced for potential use as nanofertilizers. The phase composition of the nanorods was confirmed by X-ray diffraction. Particle size and shape were investigated using transmission electron microscopy. Inductively coupled plasma mass spectrometry was used to determine the Ca:P ratio. It was shown that the use of a second mixing stage allows the particle length to be decreased down to 30 nm without compromising on crystallinity. In addition to using different mixing stages, adjusting the pH and controlling the flow speed allow wide range size tuning of the produced particles. The experimental setup allows for continuous synthesis of phase pure and highly crystalline hydroxyapatite nanorods, ensuring the reproducibility and scalability of the process. Dispersive behavior and dissolution in citrate buffer at a hydroponic pH of 5.5 were studied to evaluate further possibilities of applying produced NPs on the plants. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries have been extensively researched due to their distinctive advantages such as low cost and high safety. Vanadium oxides are important cathode materials, however, poor cycle life caused by vanadium dissolution limits their application. Recent studies show that the lattice NH4+ in vanadium oxides can act as a pillar to enhance structural stability and play a crucial role in improving its cycling stability. Nevertheless, there is still a lack of research on the effect of the lattice NH4+ content on structural evolution and electrochemical performance. Herein, we synthesize vanadium oxides with different contents of lattice NH4+ by a one‐step hydrothermal reaction. The vanadium oxides with lattice NH4+ exhibit high initial capacity, as well as good cycling stability and rate performance compared to bare vanadium oxide. Combined with electrochemical analyses, ex‐situ structural characterizations, and in‐situ X‐ray diffraction tests, we reveal that the lattice NH4+ content plays a positive role in vanadium oxides′ structural stability and cation diffusion kinetics. This work presents a direction for designing high–performance vanadium cathodes for aqueous zinc ion batteries. [ABSTRACT FROM AUTHOR]

Polymetallic composites can significantly affect the structure and active sites of materials. In this study, we prepared polymetallic organic structures using a metal-organic framework (MOF) synthesis strategy and a hydrothermal method. We controlled and adjusted the ratio of metals to create precursors, which were then calcined to produce targeted polymetallic oxides. The polymetallic oxides prepared (RuCoMoCuO x /C) demonstrated excellent properties for both HER and OER in 1.0 M KOH, with an overpotential of 136 mV @ 10 mA cm−2 for HER and 296 mV @ 10 mA cm−2 for OER. The efficient catalytic performance of dual hydrolysis is attributed to the lamellar porous structure of RuCoMoCuO x /C and the synergistic effect of each metal element in the polymetallic catalyst. DFT theoretical calculations show that when H 2 O molecules adsorb around Ru, Co, and Mo sites, OH* adsorbs at electron-deficient centers, while H+ is more readily adsorbed by electron-rich Cu sites. This unique configuration is more conducive to water dissociation. Herein, the strategy of hydrothermal synthesis of the polymetallic MOF precursor RuCoMoCuO was proposed, followed by calcination at 500 °C to form the final polymetallic oxide RuCoMoCuO x /C with abundant oxygen vacancies. The prepared RuCoMoCuO x /C nanosheets have excellent OER and HER properties. In alkaline electrolyte, when the current density was 10 mA cm−2, the overpotential was η 10 = 296 mV and 136 mV, respectively. The DFT calculation revealed that Cu as the electron-rich center was beneficial to the adsorption energy of hydrogen, while Ru, Co and Mo were the best OH adsorption sites in the electron loss center. [Display omitted] • We report the bifunctional water electrolysis catalyst RuCoMoCuO x /C. • The synthesis strategy includes ion-exchange and calcination-oxidation processes. • The porous sheet structure and metal synergism improve the OER and HER performance. • The calcination strategy promotes the formation of pores on the catalyst surface. • Oxygen vacancies exist in RuCoMoCuO x /C. [ABSTRACT FROM AUTHOR]

Here, doubly protonated Lindqvist‐type niobium oxide cluster [H2(Nb6O19)]6–, fabricated by microwave‐assisted hydrothermal synthesis, exhibited superbase catalysis for Knoevenagel and crossed aldol condensation reactions accompanied by activating C−H bond with pKa >26 and proton abstraction from a base indicator with pKa=26.5. Surprisingly, [H2(Nb6O19)]6− exhibited water‐tolerant superbase properties for Knoevenagel and crossed aldol condensation reactions in the presence of water, although it is well known that the strong basicity of metal oxides and organic superbase is typically lost by the adsorption of water. Density functional theory calculation revealed that the basic surface oxygens that share the corner of NbO6 units in [H2(Nb6O19)]8− maintained the negative charges even after proton adsorption. This proton capacity and the presence of un‐protonated basic sites led to the water tolerance of the superbase catalysis. [ABSTRACT FROM AUTHOR]

FeNbO4 sonocatalysts were successfully synthesized by a simple hydrothermal route at pH values of 3, 5, 7, 9 and 11. The catalysts were characterized by XRD, XPS, TEM, SEM, N2 adsorption and DRS to analyse the effect of pH parameters on the physicochemical properties of the materials during hydrothermal synthesis. The sonocatalytic activity of FeNbO4 microspheres was evaluated by using acid orange 7 (AO7) as the simulated contaminant. The experimental results showed that the best sonocatalytic degradation ratio (97.45%) of organic dyes could be obtained under the conditions of an initial AO7 concentration of 10 mg L−1, an ultrasonic power of 200 W, a catalyst dosage of 1.0 g L−1, and a pH of 3. Moreover, the sonocatalysts demonstrated consistent durability and stability across multiple test cycles. After active species capture experiments and calculation of the energy band, a possible mechanism was proposed based on the special Fenton-like mechanism and the dissociation of H2O2. This research shows that FeNbO4 microspheres can be used as sonocatalysts for the purification of organic wastewater, which has a promising application prospect. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) have gained recognition as a promising indoor photovoltaic technology, drawing considerable attention for their ability to convert light into electricity. In this study, we present a straightforward one-step hydrothermal synthesis method for producing cobalt sulfide nanoparticles decorated with reduced graphene oxide (CoS2/RGO) nanocomposites, serving as an efficient counter electrode (CE) material for DSSCs. The CoS2/RGO nanocomposites exhibited a chain-like structure formed by RGO nanosheet-decorated spherical particles interconnected with CoS2. Demonstrating excellent electrocatalytic activity with a low Epp (peak-to-peak separation) value, the CoS2/RGO nanocomposites outperformed pristine CoS2 nanoparticles. Moreover, the power conversion efficiency of the CoS2/RGO hybrid structure-based CE surpassed that of the pristine CoS2 nanoparticles. These findings suggest that the facile synthesis of CoS2/RGO nanocomposites holds great promise as an electrode material for effective CEs in DSSC applications. [ABSTRACT FROM AUTHOR]

A biocompatible and versatile silk‐based functional ink with hydrophilic upconversion nanoparticles (UCNPs) that can be printed or painted on arbitrary substrates, including biological surfaces is demonstrated. Hydrophilic UCNPs, ready to be dispersed in aqueous silk fibroin solution, are synthesized in large quantities via facile hydrothermal synthesis using citric acid. Based on a systematic study of dopant control to achieve robust red emission from citrate‐capped UCNPs, three primary colors are obtained, which serve as the basis for the expansion of the color palette. The synthesized UCNPs are homogeneously dispersed in regenerated silk fibroin solutions derived from Bombyx mori cocoons to produce water‐based functional inks. Cyan, magenta, and yellow (CMY) inks are created by combining red, green, and blue (RGB) inks. Demonstrator devices, where a variety of colorful patterns and codes are revealed only under near‐infrared irradiation, are realized through stencil printing or brush painting on flexible polymer films, fruit, leaves, silkworm cocoons, and pig skin. The patterns and codes are highly heat resistant (≈230 °C) and can be easily washed off with water after use. The printable/paintable inks and functions proposed here will provide new opportunities for applications where sustainability, biocompatibility, and intentional luminescence are simultaneously required. [ABSTRACT FROM AUTHOR]

Doping and particle size controlling are two important approaches to improve the electrochemical performance of LiMn x Fe 1−x PO 4 cathode materials. By employing a straightforward hydrothermal method and utilizing cost-effective lithium phosphate (Li 3 PO 4) as the precursor, we successfully synthesized high Mn-content LiMn 0.79 Fe 0.2 Mg 0.01 PO 4 /C composites. The results reveal that the minute amount of Mg substantially enhances the electrochemical performance. In the subsequent mechanism study using Li 3 PO 4 precursors with different particle size, we found that the nucleation process, dependent on specific surface area and diffusion rate, is likely to play a critical role for the size and morphology of formed LiMn 0.79 Fe 0.2 Mg 0.01 PO 4. LiMn 0.79 Fe 0.2 Mg 0.01 PO 4 /C (LMFP-1), synthesized from initially smaller-sized and less agglomerated Li 3 PO 4 (LPO-1), exhibited the most diminutive average particle size coupled with the highest specific surface area, which further facilitated electrolyte interfacial interaction and promoted Li+ diffusion kinetics. At 1C, LMFP-1 displayed a specific capacity of 110.7 mAh g−1, with 97.07% capacity retention after 200 cycles. This study provides pivotal insights for the synthesis of high-performance LiMn x Fe 1−x PO 4 materials. [Display omitted] [ABSTRACT FROM AUTHOR]

We report a study to improve the ternary oxide Ni3V2O8′s electrochemical energy storage capabilities through correct surfactanization during hydrothermal synthesis. In this study, Ni3V2O8 nanomaterials were synthesized in three different forms: one with a cationic surfactant (CTAB), one with an anionic surfactant (SLS), and one without any surfactant. FESEM study reveals that all the synthesized Ni3V2O8 nanomaterials had a small stone-like morphology. The electrochemical study showed that anionic surfactant-assisted Ni3V2O8 (NVSLS) had a maximum of 972 F g−1 specific capacitance at 1 A g−1 current density, whereas cationic surfactant-assisted Ni3V2O8 (NVCTAB) had the lowest specific capacitance of 162 F g−1. The specific capacitance and the capacitance retention of the NVSLS (85% after 4000 cycles) based electrode was much better than that of the NVCTAB (76% after 4000 cycles) based electrode. The improved energy storage properties of the NVSLS electrode are attributed to its high diffusion coefficient, high surface area, and enriched elemental nickel, as compared to the NVCTAB electrode. All these excellent electrochemical properties of NVSLS electrode indicates their potential usage in asymmetric supercapacitor application. [ABSTRACT FROM AUTHOR]

Novel flake-like Ni1−xSnxO2 particles were successfully prepared by template-free hydrothermal synthesis. The prepared samples were investigated for their properties by different characterization techniques. Scanning micrographs showed that the obtained particles consisted of nanoflakes. The X-ray diffraction results of the Ni1−xSnxO2 revealed the formation of mixed-phase Ni/SnO2 having the typical tetragonal structure of SnO2, and the cubic structure of Ni in a nanocrystalline nature. The doping with Ni had a certain influence on the host's lattice structure of SnO2 at different doping concentrations. Confirmation of the functional groups and the elements in the nanomaterials was accomplished using FTIR and EDS analyses. The electrochemical performance analysis of the prepared nanomaterials were carried out with the help of the CV, GCD, and EIS techniques. The specific capacitance of the synthesized nanomaterials with different concentrations of Ni dopant in SnO2 was analyzed at different scanning rates. Interestingly, a 5% Ni-doped SnO2 nanocomposite exhibited a maximum specific capacitance of 841.85 F g−1 at 5 mV s−1 in a 6 M KOH electrolyte. Further, to boost the electrochemical performance, a redox additive electrolyte was utilized, which exhibited a maximum specific capacitance of 2130.33 at 5 mV s−1 and an excellent capacitance retention of 93.22% after 10,000 GCD cycles. These excellent electrochemical characteristics suggest that the Ni/SnO2 nanocomposite could be utilized as an electrode material for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

An anode bimetallic catalyst comprising Ni-Pd alloy nanoparticles was loaded on acid-treatedmulti-walled carbon nanotubes (MWCNTs) for application in a direct urea fuel cell. The bimetallic catalyst and MWCNTs were synthesized by a hydrothermal method at 160°C for 5 h. To reduce the catalyst particle size, alkaline resistance, and facilitate their uniform distribution on the surface of the MWCNTs, phosphorus (P) was added to the Ni-Pd/MWCNT catalyst. The effects of P on the distribution and reduction in size of catalyst particles were investigated by Brunauer-Emmett-Teller analysis, transmission electron microscopy, and X-ray diffraction analysis. The enhanced catalytic activity and durability of the P-containing catalyst was confirmed by the high current density [1897.76 mA/cm² (vs. Ag/AgCl)] obtained at 0.45 V in a 3M KOH/1.0M urea alkaline aqueous solution compared with that of the catalyst without P [604.87 mA/cm² (vs. Ag/AgCl)], as determined by cyclic voltammetry and chronoamperometry. A Urea-O2 fuel cell assembled with a membrane electrode assembly comprising the Ni-Pd(P)/MWCNT catalyst delivered peak power densities of 0.756 and 3.825 mW/cm² at 25 and 60°C, respectively, in a 3M KOH/1M urea solution. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles (NPs) possess properties that make them suitable for a wide range of applications. In recent years, interest in the synthesis of magnetite NPs and their surface functionalization has increased significantly, especially regarding their application in biomedicine such as for controlled and targeted drug delivery. There are several conventional methods for preparing magnetite NPs, all of which mostly utilize Fe(iii) and Fe(ii) salt precursors. In this study, we present a microwave hydrothermal synthesis for the precipitation of magnetite NPs at temperatures of 200 °C for 20 min and 260 °C for 5 min, with only iron(iii) as a precursor utilizing chamomile flower extract as a stabilizing, capping, and reducing agent. Products were characterized using FTIR, PXRD, SEM, and magnetometry. Our analysis revealed significant differences in the properties of magnetite NPs prepared with this approach, and the conventional two-precursor hydrothermal microwave method (sample MagH). FTIR and PXRD analyses confirmed coated magnetite particles. The temperature and magnetic-field dependence of magnetization indicate their superparamagnetic behavior. Importantly, the results of our study show the noticeable cytotoxicity of coated magnetite NPs—toxic to carcinoma cells but harmless to healthy cells—further emphasizing the potential of these NPs for biomedical applications. [ABSTRACT FROM AUTHOR]

Hydrogen is one of the most promising green energy alternatives due to its high gravimetric energy density, zero-carbon emissions, and other advantages. In this work, a CoFeBP micro-flower (MF) electrocatalyst is fabricated as an advanced water-splitting electrocatalyst by a hydrothermal approach for hydrogen production with the highly efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The fabrication process of the CoFeBP MF electrocatalyst is systematically optimized by thorough investigations on various hydrothermal synthesis and post-annealing parameters. The best optimized CoFeBP MF electrode demonstrates HER/OER overpotentials of 20 mV and 219 mV at 20 mA/cm2. The CoFeBP MFs also exhibit a low 2-electrode (2-E) cell voltage of 1.60 V at 50 mA/cm2, which is comparable to the benchmark electrodes of Pt/C and RuO2. The CoFeBP MFs demonstrate excellent 2-E stability of over 100 h operation under harsh industrial operational conditions at 60 °C in 6 M KOH at a high current density of 1000 mA/cm2. The flower-like morphology can offer a largely increased electrochemical active surface area (ECSA), and systematic post-annealing can lead to improved crystallinity in CoFeBP MFs. [ABSTRACT FROM AUTHOR]

A composite material composed of anodized aluminum oxide (AAO), carbon (C), and magnesium oxide (MgO) was developed for CO2 capture applications. Inspired by the bryophyte organism, the AAO/C/MgO composite mirrors two primary features of these species—(1) morphological characteristics and (2) elemental composition—specifically carbon, oxygen, and magnesium. The synthesis process involved two sequential steps: electroanodization of aluminum foil followed by a hydrothermal method using a mixture of glucose and magnesium chloride (MgCl2). The concentration of MgCl2 was systematically varied as the sole experimental variable across five levels—1 mM, 2 mM, 3 mM, 4 mM, and 5 mM—to investigate the impact of MgO formation on the samples' chemical and physical properties, and consequently, their CO2 capture efficiency. Thus, scanning electron microscopy analysis revealed the AAO substrate's porous structure, with pore diameters measuring 250 ± 30 nm. The growth of MgO on the AAO substrate resulted in spherical structures, whose diameter expanded from 15 nm ± 3 nm to 1000 nm ± 250 nm with increasing MgCl2 concentration from the minor to major concentrations explored, respectively. X-ray photoelectron spectroscopy (XPS) analysis indicated that carbon serves as a linking agent between AAO and MgO within the composite. Notably, the composite synthesized with a 4 mM MgCl2 concentration exhibited the highest CO2 capture efficiency, as determined by UV-Vis absorbance studies using a sodium carbonate solution as the CO2 source. This efficiency was quantified with a 'k' constant of 0.10531, significantly higher than those of other studied samples. The superior performance of the 4 mM MgCl2 sample in CO2 capture is likely due to the optimal density of MgO structures formed on the sample's surface, enhancing its adsorptive capabilities as suggested by the XPS results. [ABSTRACT FROM AUTHOR]

Zeolite has good physicochemical properties such as adsorption, cation exchange, molecular sieving and catalysis to be widely used as selective scavengers of heavy metals from liquid effluents. In this paper, the synthesis method of 13X zeolite using fine granite dust (FGD) resulting from granite processing has been investigated. Both alkaline fusion method (770–830 °C, 80 min) and hydrothermal process (95–100 °C, 8–12 h) were selected and applied to the synthesize of 13X zeolite. A major disadvantage of synthesis of zeolite by using alkaline fusion method is high sintering temperature. The sintering temperature was lowered from 1300 to 800 °C by putting FGD into water and maintaining for 5 min to remove crystalline quartz which has low reactivity. On the other hand, it is important to find rational sintering temperature at which albite is decomposed more easily than kalifeldspar in FGD because 13X zeolite is chemically concerned with sodium (Na). For this, reaction heats of kalifeldspar and albite were calculated at the temperature range of 770–830 °C. As a result, it was proved that albite has the possibility to be dissolved thermodynamically more easily than kalifeldspar, but the difference between the heat effects of albite and kalifeldspar is not altered too much in proportion to the increase of temperature. Eventually, 13X zeolite has been successfully synthesized from FGD with low energy and all the other stone processing waste can be recycled by this method. [ABSTRACT FROM AUTHOR]

We report a study to improve the ternary oxide Ni3V2O8′s electrochemical energy storage capabilities through correct surfactanization during hydrothermal synthesis. In this study, Ni3V2O8 nanomaterials were synthesized in three different forms: one with a cationic surfactant (CTAB), one with an anionic surfactant (SLS), and one without any surfactant. FESEM study reveals that all the synthesized Ni3V2O8 nanomaterials had a small stone-like morphology. The electrochemical study showed that anionic surfactant-assisted Ni3V2O8 (NVSLS) had a maximum of 972 F g−1 specific capacitance at 1 A g−1 current density, whereas cationic surfactant-assisted Ni3V2O8 (NVCTAB) had the lowest specific capacitance of 162 F g−1. The specific capacitance and the capacitance retention of the NVSLS (85% after 4000 cycles) based electrode was much better than that of the NVCTAB (76% after 4000 cycles) based electrode. The improved energy storage properties of the NVSLS electrode are attributed to its high diffusion coefficient, high surface area, and enriched elemental nickel, as compared to the NVCTAB electrode. All these excellent electrochemical properties of NVSLS electrode indicates their potential usage in asymmetric supercapacitor application. [ABSTRACT FROM AUTHOR]

NIR luminescent materials have garnered widespread attention because of their exceptional properties, with high tissue penetration, low absorption and high signal-to-noise ratio in the field of optical imaging. However, producing nanophosphors with high quantum yields of emitting infrared light with wavelengths above 1000 nm remains a significant challenge. Here, we prepared a nanoscale ZnGa2O4:xCr3+,yNi2+ phosphor with good luminescence performance in near-infrared emission, which was synthesized via a hydrothermal method and subsequent calcination process. By co-doping with Cr3+ and Ni2+, the ZnGa2O4 phosphor shows a strong broadband emission of 1100-1600 nm in the second near-infrared (NIR-II) region, owing to the energy transfer from Cr3+ to Ni2+ with an efficiency up to 90%. Meanwhile, a near-infrared phosphor-conversion LED (NIR pc-LED) device is fabricated based on the ZnGa2O4:0.8% Cr3+,0.4%Ni2+ nanophosphor, which has under 100 mA input current, an output power of 23.99 mW, and a photoelectric conversion efficiency of 7.53%, and can be effectively applied in imaging and nondestructive testing. Additionally, the intensity ratio of INi/ICr of ZnGa2O4:0.8% Cr3+,0.4%Ni2+ with its high sensitivity value of 4.21% K-1 at 453 K under 410 nm excitation, indicates its potential for thermometry application. [ABSTRACT FROM AUTHOR]

Development of Nano-heterostructures based on transition metal chalcogenides is promising strategy to accelerate the catalytic performance for hydrogen evolution reaction (HER) and supercapacitor application. The design and development of non-noble transition metal based catalysts is required for the low-cost, efficient and earth-abundant electrodes for sustainable energy conversion and storage. ReS 2 /CoS heterostructures were synthesized by two step methods involving liquid phase exfoliation of ReS 2 and hydrothermal decoration of CoS. The prepared ReS 2 /CoS heterostructures shows high performance supercapacitor applications with specific capacitance of 663.2 F/g at 2 A/g and 643.1 F/g at scan rate 5 mV/s, showing enhanced redox reaction and number of electrochemically active sites due to synergistic effect and modulated electronic structure. Additionally, ReS 2 /CoS heterostructures shows the superior HER performance in alkaline condition with overpotential of 187 mV at 10 mA/cm2 due to accelerated kinetics, enhanced ECSA and low charge transfer resistance. The ReS 2 /CoS heterostructures shows the stable electrochemical performance for HER for more than 17 h. • This article reports the facile synthesis of ReS 2 /CoS heterostructure catalyst. • Nano-interface engineering facilitates the enhanced HER and supercapacitor performance. • The specific capacitance of 663.2 F/g at 2 A/g and 643.1 F/g at scan rate 5 mV/s are achieved. • Superior HER in alkaline condition with overpotential of 187 mV at 10 mA/cm2 have been achieved. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) is a promising anode material for lithium-ion batteries (LIBs) due to its distinctive graphene-like structure and high specific capacity. However, its commercial application is hindered by the severe volume expansion during lithiation/delithiation and poor conductivity. In this paper, we report a facile one-pot enhanced hydrothermal synthesis strategy to prepare high-performance MoS2/C composite materials. The results indicate that the as-prepared MoS2/C composite is a subspheroidal core–shell structure material, with uniform coating, good particle dispersion, and an average grain size of approximately 80 nm. The morphology of the composite remained unchanged even after annealing at 500 °C for 2 h. The addition of glucose can accelerate the nucleation and growth of MoS2, and higher hydrothermal temperatures can improve the product yield. The addition of PVP has little effect on the yield, but significantly reduces the particle size. The XPS analysis reveals that the MoO3 may be generated as an intermediate product during the hydrothermal process. The electrochemical test results show that the unannealed MoS2/C samples exhibit discharge-specific capacities of 705.2 mAh·g−1 and 625.7 mAh·g−1 after the first cycle and the 100th cycle, respectively, at a current density of 500 mA·g−1, with a capacity retention rate of 88.7%. In contrast, the specific capacity of the MoS2/C specimens after annealing at 500 °C for 2 h shows a tendency to decrease and then slowly increase during the cycles, and the discharge specific capacity is 582.3 mAh·g−1 after the 100th cycle, which is lower than that of the unheated sample. The impedance analysis reveals that the lithium-ion diffusion coefficient of the MoS2/C material without calcination is 2.11 × 10−18 cm·s−2, which is superior to that of the annealed MoS2/C and pristine MoS2 samples. This characteristic is favorable for lithiation/delithiation during the charge/discharge process. [ABSTRACT FROM AUTHOR]

Improving the electrochemical performance of electrode materials via structural design is critical in developing energy storage technologies. In this investigation, a nanoarray electrode composed of Co–Ni layered double hydroxide (Ni–Co LDH) nanosheets and Ni2SnO4 nanosheets (Ni2SnO4 NSs) stabilized on Ni foam (NF) is developed utilizing an in-situ growth method to its electrochemical properties in supercapacitors can be evaluated. The Ni2SnO4 was created in the first stage using a light hydrothermal reaction as the core. The Ni–Co LDH was then hydrothermally immobilized using the electrode, which had been made as a skeleton. The structural and textural study of the material was described using energy dispersive X-ray analysis (XRD), Fourier transforms infrared (FT–IR), field-emission scanning electron microscopy, and transmission electron microscopy. When the developed Ni–Co LDH/Ni2SnO4/NF electrode is compared to the Ni2SnO4/NF electrode, the electrochemical result shows a specific capacitance of up to 3,924 F g−1 at 1 A g−1 in a 2 mol L−1 KOH electrolyte, as well as a capacitance retention of 95% after 3000 cycles. Unsymmetrical supercapacitors made of Ni–Co LDH/Ni2SnO4/NF and activated carbon demonstrated exceptional electrochemical properties, including high rate capability, high energy, and power density (91.03 Wh kg−1 and 9.0 kW kg−1, respectively), and long cycle life. Due to its unique core/shell structural system, which facilitates ion diffusion and offers a fast electron transport kinetic model and good strain lodging, the rising pseudocapacitive behaviors render it an intriguing candidate for electrochemical energy storage. [ABSTRACT FROM AUTHOR]

Hydrothermally reduced chemical method synthesis of rGO-TiO2 nanocomposites (NCs) with varied concentrations of graphene oxide (GO) from 1 to 5 wt% was investigated for its morphological, structural, chemical bonding, structural defects, optical and electrochemical properties. Formation of rGO-TiO2 NCs was confirmed from SEM and EDX analysis where the average particle size of TiO2 nanoparticles dispersed over reduced graphene oxide (rGO) sheets increased from 46.2 to 71.2 nm. The diffraction peaks study from XRD reveals the TiO2 phase in the anatase structure which is well supported by Raman results presenting the vibrational modes of Eg (1), Bg (1), A1g+B1g (2), and Eg (2) located at 146.1, 392.1, 513.2, and 638.1 cm−1. The average crystallite size of rGO-TiO2 NCs varied from 37.6 to 39.8 nm and lattice strain decreased from 0.0014 to 0.00135. The presence of the combination of Ti–O–Ti and Ti–O–C vibrational signatures indicates the effective interaction between Ti and C and the chemical bond formation between TiO2 and rGO which is justified by X-ray photoelectron spectroscopy. Electrochemical measurements showed that the specific capacitance of rGO-TiO2 NCs varied from 204.7 to 276.4 F g−1 at a 5 mV s−1 scan rate with the maximum specific capacitance obtained for 5% rGO-TiO2 NC. The lowest charge transfer resistance was recorded for 5% rGO-TiO2 NC (63.86 Ω) which is consistent with the maximum specific capacitance achieved. Moreover, corrosion studies reveal that corrosion potential becomes more positive with more rGO content obtaining a maximum of 0.297 V in 5% rGO-TiO2 NC. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have demonstrated remarkable development potential and commercial prospects. However, in the current state of research, the development of high-energy-density, long-cycle-life, high-rate-performance anode materials for SIBs remains a huge challenge. Free-standing flexible electrodes, owing to their ability to achieve higher energy density without the need for current collectors, binders, and conductive additives, have garnered significant attention across various fields. In this work, we designed and fabricated a free-standing three-dimensional flexible Nb2O5@WS2@C carbon nanofiber (CNF) anode based on a hybrid adsorption–intercalation–conversion mechanism of sodium storage, using electrospinning and hydrothermal synthesis processes. The hybrid structure, aided by synergistic effects, releases the advantages of all materials, demonstrating a superior rate performance (288, 248, 211, 158, 90, and 48 mA h g−1 at the current density of 0.2, 0.5, 1, 2, 5, and 10 A g−1, respectively) and good cycling stability (160 mA h g−1 after 200 cycles at 1 A g−1). This work provides certain guiding significance for future research on hybrid and flexible anodes of SIBs. [ABSTRACT FROM AUTHOR]

Titanium and its alloys are extensively applied in artificial tooth roots because of their excellent corrosion resistance, high specific strength, and low elastic modulus. However, because of their biological inertness, their surface needs to be modified to improve the osteointegration of titanium implants. The preparation of biologically active calcium–phosphorus coatings on the surface of an implant is one effective method for enhancing the likelihood of bone integration. In this study, osteoinductive peptides were extracted from oyster shells by using acetic acid. Two peptide-containing hydroxyapatite (HA) composite coatings were then prepared: one coating was prepared by hydrothermally synthesizing an HA coating in the presence of peptides (HA/P/M), and the other coating was prepared by hydrothermally synthesizing HA and then immersing the hydrothermally synthesized HA in a peptide solution (HA/P/S). Characterization results indicated that the composite HA coatings containing oyster shell-based peptides were successfully prepared on the alkali-treated pure titanium surfaces. The HA/P/M and HA/P/S composite coatings were found to exhibit excellent hydrophilicity. Protein adsorption tests confirmed that the HA/P/M and HA/P/S coatings had an approximately 2.3 times higher concentration of adsorbed proteins than the pure HA coating. [ABSTRACT FROM AUTHOR]

Cyano-bridged layered coordination polymer [Cu8(dpe)4(CN)8]·2dpe·H2O (1) is prepared by the hydrothermal reaction of CuCN and dpe (dpe = 1,2-di-4-pyridylethylene) in the presence of Cs3K[Re6S8(CN)6]·2H2O. The [Cu8(dpe)4(CN)8] complex is an isomer of the earlier described [Cu2(CN)2(dpe)] with a 3D framework structure. The structure of 1 is triclinic, space group, a = 11.9229(8) Å, b = 11.9549(8) Å, c = 14.1984(10) Å, α = 102.019(2)°, β = 102.370(2)°, γ = 104.151(2)°, V = 1842.8(2) Å3, Z = 1, dcalc = 1.647 g/cm3. The Cu atoms in 1 have a triangular coordination environment formed by N atoms of the bridging dpe molecule and N and C atoms of the ambidentate bridging CN ligands. [ABSTRACT FROM AUTHOR]

In this work, we synthesize hierarchical In2S3/NiFe-layered double hydroxide (In2S3/NiFe-LDH) nanoarrays on an F-doped SnO2 glass substrate via a two-step method, which the In2S3 electrode film was firstly prepared using chemical bath deposition on F-doped SnO2 glass substrate, and then the layered NiFe-LDH was deposited on In2S3 electrode film by hydrothermal synthesis. The two-component photoanode In2S3/NiFe-LDH exhibits significantly enhanced photoelectrochemical properties compared with the In2S3 single-component; due to that, the NiFe-LDH nanosheets depositing on the surface of In2S3 nanocrystal can reduce the accumulation of photogenic holes, facilitate the separation of photogenerated charge carriers, and enhance the light response and absorption. After being decorated with the NiFe-LDH nanosheets, the In2S3/NiFe-LDH photoanode displays a lower onset potential of 0.06 V and an enhanced photocurrent density as high as 0.30 mA·cm−2 at the potential of 1.0 V (vs. RHE). Furthermore, it also displays a 90% degradation rate of xylose oxidizing into xylose acid in 3 h under UV light. This work provides a promising approach for designing new heterojunctions applied to biomass degradation. [ABSTRACT FROM AUTHOR]

The present study uses the hydrothermal method to prepare nickel aluminum layered double hydroxidefunctionalized humic acid and magnetite. Scanning electron microscopy, Fourier transfer infra-red, X-ray diffraction, N2 adsorption-desorption isotherm, and vibrating sample magnetometer measurements are also used to determine the adsorbent’s physicochemical properties. The mesopore-filling activity of Ni/Al functionalized humic acid and magnetite facilitates malachite green adsorption. Ni/Al functionalized humic acid and magnetite was collected from the water solution with a small additional magnet. Ni/Al and Ni/Al functionalized humic acid and magnetite exhibited type-IV sorption isotherms with the surface area of Ni/Al quadruples following functionalization with humic acid and magnetite. The pseudo-second-order kinetic and Langmuir isotherm adequately describe the adsorption process of the batch system. In the current case, the interaction of humic acid, magnetite, and the Ni/Al component may impact the leaching kinetics. Various factors, including pH, temperature, and competing ions, can impact the release of malachite green from the adsorbent surface. Malachite green has maximal Langmuir adsorption capacities of 68.966 mg/g and 178.571 mg/g on Ni/Al and Ni/Alfunctionalized humic acid and magnetite, respectively. The result of the physisorption interaction processes was its efficient adsorption capacity for malachite green. This study offered recommendations on the development of adsorbents with high efficiency for the adsorption of malachite green. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting stands as a promising method for harnessing energy from renewable sources. However, substantial overpotential required for sluggish oxygen evolution reaction (OER) hampers its widespread adoption. In this study, a CuSe@PPy hybrid is being created by hydrothermally layering polypyrrole on top of CuSe. This hybrid electrocatalyst outperforms both pure CuSe and PPy in terms of OER efficiency. Structural and morphological analyses, including powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller (BET), confirm that the synthesized CuSe@PPy composite exhibits high crystallinity, nanostructured granular morphology, and a hexagonal structure with a large surface area. Evaluation of its electrocatalytic performance for water oxidation in a 1 M KOH alkaline medium reveals CuSe@PPy hybrid's exceptional durability, achieving 35 mA cm−2 for 100 h. This durability is attributed to PPy coating on its surface, which facilitates efficient electron conduction. Coupling of PPy with CuSe leads to reduced overpotential (248 mV), a lower Tafel slope (30 mV/dec), and decreased charge transfer resistance (2.16 Ω), enhancing OER efficiency. By modifying surface of CuSe with a conducting polymer like PPy, this study underscores potential for improving performance in various applications, including photoelectron-catalytic research and stabilizing material activity. [ABSTRACT FROM AUTHOR]

The low-temperature (α-/β-/γ-/δ-MnO2/CeO2-Nanorod) catalysts have been synthesized using the hydrothermal method followed by wet-impregnation and anaylzed in the Inconel reactor for selective catalytic reduction of NO using NH3 as a reducing agent. The catalysts were characterized by the Brunauer-Emmett characterized catalysts–Teller, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy-Energy dispersive X-ray spectroscopy, transmission electron microscopy and Raman spectroscopy. The characterization analysis of the catalysts revealed that the α-MnO2/CeO2-Nanorod has the highest specific surface area, surface Ce3+ and Mn4+, and oxygen storage capacity among all the catalysts. The activity results exhibited that in the 50–450 °C temperature range, the α-MnO2/CeO2-Nanorod has the maximum NO conversion and N2 selectivity. It showed the highest NO conversion (75%) and N2 selectivity (86%) at 250 °C. As the amount of α-MnO2 increased in the α-MnO2/CeO2-Nanorod catalyst, the NO conversion with N2 selectivity exceeded 94.25% and 95%, respectively. [ABSTRACT FROM AUTHOR]

This work presents a facile hydrothermal synthesis method for fabricating a multifunctional composite of copper zinc tin sulfide (CZTS) nanoparticles coated onto sepiolite fibers. Morphological analysis confirms the firm attachment of approximately 10 nm CZTS nanoparticles onto the sepiolite surface. Elemental analysis verifies the presence of constituent elements from both CZTS and sepiolite, with a slight deficiency in Cu and an abundance of Zn observed. The compositional formula of CZTS in the composite is estimated as Cu1.93Zn1.05Sn0.98S4.04. Notably, the material exhibits a narrow band gap of 1.5 eV, enabling effective utilization of the entire visible light spectrum, making it promising for photocatalytic applications. BET nitrogen adsorption/desorption measurements reveal a substantial surface area of approximately 85.720 m²/g, confirming the composite's versatility and applicability, particularly in photocatalysis and adsorption processes. Additionally, X-ray diffraction analysis indicates reflections consistent with the crystal structures of kasterite CZTS and sepiolite, further confirming the composite's composition. The multifunctional CZTS/Sepiolite composite demonstrates exceptional potential for simultaneous photocatalytic degradation and adsorption of organic pollutants, presenting a promising avenue for sustainable water treatment applications. [ABSTRACT FROM AUTHOR]