One-step Solvothermal Process Research Articles

Yellow Emissive Carbon Dots - A Robust Nanoprobe for Highly Sensitive Quantification of Jaundice Biomarker and Mitochondria Targeting in Cancer Cells.

The abnormally high level of bilirubin (BR) in biofluids (human serum and urine) indicates a high probability of jaundice and liver dysfunction. However, quantification of BR as the Jaundice biomarker is difficult due to the interference of various biomolecules in serum and urine. To address this issue, we developed a fluorescence-based detection strategy, for which yellow emissive carbon dots (YCDs) were produced from a one-step solvothermal process using phloroglucinol and thionin acetate as chemical precursors. The as-fabricated YCDs exhibited a strong fluorescence peak at the wavelength of 542 nm upon excitation at 390 nm. We used YCDs for detecting BR through the fluorescence turn-off mechanism, unveiling the excellent sensitivity in the linear range of 0.5-12.5 μM with a limit of detection (LOD) of 9.62 nM, which was far below the clinically relevant range. The analytical nanoprobe also offered excellent detection specificity for quantifying BR in real samples. Moreover, the biocompatible fluorescent nanoprobe was successfully employed to target mitochondria in live cancer cells. A colocalization study confirmed that YCDs possessed the ability to target mitochondria and overlapped completely with MitoTracker Red. The developed nanoprobe of YCDs turned out to be straightforward in their synthesis, noninvasive, and can be utilized for biomedical sensors to diagnose the onset of jaundice as well as for mitochondria targeting.

One-Step Synthesis of Graphene-Covered Silver Nanowires with Enhanced Stability for Heating and Strain Sensing.

Solution-processed silver nanowire (AgNW) networks have been considered as promising electrode candidates for next-generation electronic devices. However, they suffer from poor thermal and electrical stability and low mechanical properties, hindering their practical applications. In this work, graphene nanosheets are successfully introduced into AgNW via a facile one-step solvothermal process. Benefiting from increased conductive paths, the resultant AgNW/graphene films exhibit high electrical conductivity. More importantly, the interlocking NW morphology can be maintained under high temperature and applied voltage due to suppressed Ag migration, which is enabled by the introduction of graphene. This feature leads to enhanced thermal and electrical stability, making them suitable for use as transparent heaters. Furthermore, the composite films present excellent mechanical performance, and negligible resistance change is observed after 10 000 repeated bending cycles. To demonstrate their feasibility toward sensor applications, sandwiched strain sensors are designed, which can endure larger tensile strains and show higher sensitivity and repeatability compared with pure AgNW-based device. Furthermore, various hand gestures can be easily recognized by the resultant sensors based on unique combinations of sensing response. This work not only provides a low-cost method to realize large-scale synthesis of AgNW/graphene composites but also offers guidance to prepare high-performance electrodes for advanced electronics.

New solvothermal flow synthesis of strontium titanate nanoparticles based on the use of acetylacetonate precursors in water/ethanol mixture

In this study, strontium titanate (SrTiO3) nanoparticles were obtained utilizing a one-step supercritical continuous solvothermal synthesis process involving acetylacetonate precursors for both strontium and titanium cations instead of the historical alkoxide ones. These precursors are expensive, difficult to access (especially for strontium isopropoxyde) and inadequately stable, forcing the use of a glove box and controlled atmospheres, which is not the case for acetylacetonates. Pure SrTiO3 nanoparticles with a crystallite size of roughly 20 nm were successfully synthesized. In addition to the cubic structure of SrTiO3, FTIR revealed surface functions that are typical of "wet" processes, while Raman spectroscopy showed the activation of non-centrosymmetric modes brought on by non-linear contributions. The nanoparticles show a faceted shape and are stable at elevated temperatures (up to 800 °C), according to in-situ high temperature XRD measurements. However, due to a chemical deficiency in strontium, titanium dioxide (TiO2) phases are formed at higher temperatures. In-situ high temperature HRTEM investigations showed the existence of two populations of particles, with a better stability for the bigger-sized particles after thermal treatment as well as the sintering and restructuring of the smallest ones. Also, the microscopy results suggest the possibility of a chemical inhomogeneity within the crystallites. Overall, this study offers important new knowledge on the physicochemical characteristics of the synthesized SrTiO3 nanoparticles and their thermal stability using a novel supercritical continuous solvothermal approach based on the use of acetylacetonate precursors.

Nitro-functionalization on MIL-53(Fe) for PCMX degradation: Elevating Fenton-like catalytic propelled by abundant reaction sites and iron cycle

To address the issue of excessive residues of 4-chloro-3,5-dimethylphenol (PCMX) in the water environment. In a one-step solvothermal process, iron-based metal-organic frameworks (Fe-MOFs) material MIL-53(Fe) undergoes a synthetic modification strategy. 2-Nitroterephthalic acid as an organic ligand reacted with Fe3+ in a solvothermal process lasting 18 h to yield the nitro-functionalized MIL-53(Fe)–NO2(18h). The objective was to augment the abundance of Fe central unsaturated coordination sites (Fe CUCs) and expedite the Fe(III)/Fe(II) redox cycle, thereby enhancing the heterogeneous Fenton-like treatment capability of pollutants. MIL-53(Fe)–NO2(18h) has excellent hydrogen peroxide (H2O2) catalytic activity and PCMX degradation across a broad pH spectrum (4.0∼8.0). Almost complete removal of PCMX was achieved within 30 min, while pseudo-first-order kinetic rate constants (kobs) increased 4.37 times over MIL-53(Fe). The confirmation of increased Fe CUCs abundance in MIL-53(Fe)–NO2(18h) was achieved through Lewis acidity, oxygen vacancies (OVs) signals, and Fe–O coordination characterization results. Density functional theory (DFT) calculations revealed that Fe CUCs in MIL-53(Fe)–NO2(18h) exhibits heightened affinity for H2O2 adsorption, showcasing stronger charge transfer and enhanced H2O2 dissociation ability. The Fe(III)/Fe(II) redox cycle, a driving force of Fenton-like reactions, was notably improved in the nitro-modified materials. These enhancements significantly expedited the Fenton-like process, resulting in the generation of increased amounts of reactive oxygen species (ROSs), with hydroxyl radicals (OH·) being pivotal components in degradation. The MIL-53(Fe)–NO2(18h)/H2O2 system has demonstrated versatility in treating a variety of emerging contaminants, achieving removal efficiencies exceeding 99.7% for other antibiotics and endocrine disruptors within 60 min. Furthermore, MIL-53(Fe)–NO2(18h) demonstrated outstanding reusability and adaptability in actual water environments. This study introduces a straightforward and environmentally friendly strategy for remediating environmental pollution using Fe-MOF-catalysed heterogeneous Fenton-like technology.

Surface-enhanced Raman spectroscopy sensing of Huangjiu's total antioxidant capacity utilizing polyoxometalate-based frameworks nanozymes

The ability to accurately assess the total antioxidant capacity (TAC) of Huangjiu is essential for the comprehensive assessment of its nutritional and medicinal benefits. Consequently, developing a rapid, sensitive and specific analytical methodology to determine TAC is an urgent research need. In this work, we explored the potential of a one-step solvothermal process, leading to the synthesis of polyoxometalates-metal-organic frameworks (POMs-MOFs), H3PW12O40 (HPW)-CuBTC materials, which possess a high surface area and considerable active sites. Our results demonstrated that HPW-CuBTC materials exhibit remarkable surface-enhanced Raman scattering (SERS) activity, capable of detecting 10–8 M methylene blue (MB). SERS activity was attributed to both the localized surface plasmon resonance (LSPR) and charge transfer (CT) synergistic enhancement mechanisms. Furthermore, HPW-CuBTC materials exhibited peroxidase (POD)-like activity, with a catalytic mechanism involving a synergistic catalytic effect between HPW and CuBTC. We developed a catechin sensor based on the POD-like properties of HPW-CuBTC, with a linear range from 4 μM to 8 μM (R2=0.98). Additionally, we utilized the HPW-CuBTC materials to construct a TAC sensing platform in Huangjiu. This work introduces new technologies and methodologies for rapid trace detection of TAC in Huangjiu, providing a valuable tool for evaluating its nutritional and medicinal benefits.

Hydrothermal Synthesis of SnO2 with Different Morphologies as Sensing Materials for HCHO Detection.

Morphology regulation is an effective strategy for improving the sensor sensitivity of transition metal oxide nanostructures. In this work, SnO2 with three different morphologies (nanorods, nanoparticles, and nanopillars) has been synthesized by a simple one-step solvothermal process with the addition of various solute ratios at 180 °C for 6 h for detecting formaldehyde (HCHO) at the optimum working temperature of 320 °C. Compared to nanorods and nanopillars, the created SnO2 nanoparticles exhibit a much faster response time and sensitivity than other samples, showing the fastest recovery time (18 s) with the highest sensitivity of 6-100 ppm of the HCHO gas. The sensing mechanism of the sensors is investigated by Brunauer-Emmett-Teller (BET) methods and X-ray photoelectron spectroscopy (XPS) analysis, revealing that the pore size distribution and amount of OV and OC improve the charge transfer and HCHO adsorption of nanoparticle sensors. Such an effect of morphology control on sensing performance paves an idea for the development of different structure-based HCHO sensors.

Tailored thickness engineering of Bi2Se3 nanosheets for superior cathodic performance in aqueous zinc-ion batteries

Bi2Se3 is considered a suitable cathode material for zinc-ion batteries (ZIBs) because of its high conductivity and large layer spacing. Herein, Bi2Se3 nanosheets with varying thicknesses are successfully synthesized using a one-step solvothermal process with adding different amounts of ethylenediamine. The introduction of ethylenediamine reduces the thickness of Bi2Se3 from 250 nm to 22.7 nm. The thin structure exposes more active sites and shortens ion transport paths. Therefore, the optimized Bi2Se3 nanosheet exhibits outstanding specific capacity (410 mA h g−1 at 0.2 A/g), high-rate performance (230 mA h g−1 at 5 A/g), and remarkable cycling stability (82.3 % capacity retention after 1200 cycles at 5 A/g). Furthermore, an in-depth exploration of cathodes during cycling is conducted to investigate the charge/discharge mechanism. A dynamic phase transition from Bi2Se3 to BiSe, accompanied by nanosheet exfoliation, is observed during the initial few cycles, designating BiSe as the primary active material. Moreover, an additional redox reaction involving multiple electrons has been proposed. This study offers a valuable guidance for utilizing Bi2Se3 as a cathode in ZIBs.

Eco-friendly and efficient sulfamic acid functionalized MIL-53 (Al) nanocomposite for removal of hazardous pollutants from wastewater and catalytic synthesis of 3,4-dihydropyrimidinone pharmacological moiety

This study proposed the facile synthesis of sulfamic acid functionalized MIL-53 (Al) (SA@MIL-53(Al)) nanocomposite for dual-functional pollutant removal and catalytic synthesis. The composite was synthesized through a facile, straightforward, and one-step solvothermal process. Furthermore, different analysis techniques like XRD, SEM, XPS, FT-IR, and TGA were applied to examine the prepared composites' structure properties, confirming the successful preparation of functionalized frameworks. Several factors, including the initial concentration of pollutants, adsorbent dosage, pH, and pHpzc, have been established to optimize the suitable parameters for adsorption. 25 wt.% SA@MIL-53(Al) has the greatest adsorption capacities of 146.5, 97.7, and 35.5 mg g−1 for removing MB, CR dyes, and Pb (II), respectively. The rate-limiting steps were also discussed, and the experimental adsorption measurements obeyed the Langmuir and the pseudo-second-order kinetic models. Moreover, the fabricated composites were used as catalysts to produce 3,4-dihydropyrimidinone (3,4-DHP). 50 wt.% SA@MIL-53(Al) demonstrated the highest efficiency, nearly 92.0 %, with great durability and stability.

Deep eutectic solvent-induced controllable synthesis of bifunctional Ni–Fe–P catalysts for electrochemical water splitting

Developing electrocatalysts with excellent activity, high stability, and low cost is vital for large-scale hydrogen production through electrochemical water splitting. Herein, a bifunctional Ni–Fe–P catalyst in situ grown on Fe foam (Ni–Fe–P/FF) is developed by a simple one-step solvothermal process in the deep eutectic solvent (DES) of ethylene glycol and choline chloride (named Ethaline). The unique solvent environment of Ethaline assisted with the regulating effect of the introduced Fe(III) ions shows an essential role in governing the preparation process. The developed Ni–Fe–P/FF acts as the efficient bifunctional electrocatalyst for water splitting in 1.0 M KOH, requiring overpotentials of 82 mV (229 mV) and 263 mV (370 mV) to deliver 10 mA cm−2 (100 mA cm−2) for oxygen and hydrogen evolution reactions, respectively. Furthermore, the self-supported catalyst-assembled electrolyzer also exhibits good catalytic performance with a low voltage of 1.83 V to drive 100 mA cm−2 and good stability over 100 h. This work offers a facile approach to fabricating high-performance bifunctional Ni–Fe–P electrocatalysts to catalyze water splitting.

One-step growth of ultrathin CoSe2 nanobelts on N-doped MXene nanosheets for dendrite-inhibited and kinetic-accelerated lithium–sulfur chemistry

The practical application of lithium–sulfur (Li–S) batteries is inhibited by the shuttle effect of lithium polysulfides (LiPSs) and slow polysulfide redox kinetics on the S cathode as well as the uncontrollable growth of dendrites on the Li metal anode. Therefore, both cathode and anode sides must be considered when modifying Li−S batteries. Herein, two-dimensional (2D) ultrathin CoSe2 nanobelts are in situ grown on 2D N-doped MXene nanosheets (CoSe2@N-MXene) via one-step solvothermal process for the first time. Owing to its unique 2D/2D structure, CoSe2@N-MXene can be processed to crumpled nanosheets by freeze-drying and flexible and freestanding films by vacuum filtration. These crumpled CoSe2@N-MXene nanosheets with abundant active sites and inner spaces can act as S hosts to accelerate polysulfide redox kinetics and suppress the shuttle effect of LiPSs owing to their strong adsorption ability and catalytic conversion effect with LiPSs. Meanwhile, the CoSe2@N-MXene film (CoSe2@NMF) can act as a current collector to promote uniform Li deposition because it contains lithiophilic CoSe2 and N sites. Under the systematic effect of CoSe2@N-MXene on S cathode and Li metal anode, the electrochemical and safety performance of Li–S batteries are improved. CoSe2@NMF also shows excellent storage performances in flexible energy storage devices.

Solvothermal growth of silver-doped vanadium pentoxide microurchins as a cathode material for all-solid-state asymmetric supercapacitors

This study aims to improve the electrochemical properties of vanadium pentoxide by inserting silver cations into the vanadium oxide lattice. The porous silver-doped V2O5 (Ag-V2O5) microurchins were grown via a facile one-step solvothermal process. The enhanced mesoporosity and interlayer d-spacing upon silver-doping, as confirmed by Brunauer–Emmett–Teller (BET) and X-ray diffraction analyses, played an important role in facilitating the intercalation/de-intercalation of electrolyte ions and thus enhancing the capacitive performance of V2O5. The Ag-V2O5 electrode delivered a superior capacitance of 535.6 F/g at 0.5 A/g and a higher rate capacity of 78.8% in non-aqueous lithium perchlorate electrolyte compared to sodium perchlorate electrolyte. Furthermore, the specific capacitance of V2O5 was remarkably increased by ∼56% upon 5.33 at% Ag-doping. An all-solid-state asymmetric supercapacitor (ASC) was fabricated using Ag-V2O5 as the cathode, activated carbon cloth as the anode, and LiClO4-loaded poly(acrylonitrile-co-1-vinylimidazole-co-itaconic acid) as a solid electrolyte. The ASC was stably operating in a wide potential window of 0–1.6 V and delivered a high energy of 53.8 Wh kg−1. Most importantly, the ASC exhibits a slow self-discharge rate with only 7.7% voltage loss after 17 h when charged at 1.6 V. Hence, these impressive electrochemical performances of Ag-V2O5 make it a promising cathode material for next-generation supercapacitors.

Green synthesis of iron-doped graphene quantum dots: an efficient nanozyme for glucose sensing.

Single-atom nanozymes with well-defined atomic structures and electronic coordination environments can effectively mimic the functions of natural enzymes. However, the costly and intricate preparation processes have hindered further exploration and application of these single-atom nanozymes. In this study, we presented a synthesis technique for creating Fe-N central single-atom doped graphene quantum dot (FeN/GQDs) nanozymes using a one-step solvothermal process, where individual iron atoms form strong bonds with graphene quantum dots through nitrogen coordination. Unlike previous studies, this method significantly simplifies the synthesis conditions for single-atom nanozymes, eliminating the need for high temperatures and employing environmentally friendly precursors derived from pineapple (ananas comosus) leaves. The resulting FeN/GQDs exhibited peroxidase-like catalytic activity and kinetics comparable to that of natural enzymes, efficiently converting H2O2 into hydroxyl radical species. Leveraging their excellent peroxide-like activity, FeN/GQDs nanozymes have been successfully applied to construct a colorimetric biosensor system characterized by remarkably high sensitivity for glucose detection. This achievement demonstrated a promising approach to designing single-atom nanozymes with both facile synthesis procedures and high catalytic activity, offering potential applications in wearable sensors and personalized health monitoring.

A dual-ligand lanthanide-based metal-organic framework for highly selective and sensitive colorimetric detection of Fe2.

Accumulation of heavy metals in humans and mammals causes health problems due to their abundance as transition metal ions. Iron (Fe2+) serves significantly in numerous biological processes as a heavy metal ion. In this study, we have designed and prepared a metal-organic framework (MOF) utilizing a one-step solvothermal process, incorporating a dual-ligand combination of terephthalic acid (H2BDC) and α,α',α''-tert-pyridine (TPY) with Eu3+ as the metal node. For this MOF, we termed it Eu-BDC/TPY. Eu-BDC/TPY has superior selectivity over other metal cations. It provides an accurate, sensitive, broad linear range colorimetric method for detecting Fe2+ in a concentration range of 1-50 μM with a modest limit of detection (0.33 μM). Eu-BDC/TPY detects the absence of Fe2+ quickly (within 5 seconds), which is very valuable in practical applications. In addition, the results can be used to create a digital image colorimetric card (DIC) using colorimetric software, enabling instantaneous detection of Fe2+ concentration using a smartphone.

ZIF-8 membranes on ZIF-8-PVDF/PVDF dual-layer polymeric hollow fiber supports for gas separation

ZIF-8 membranes have attracted extensive research attention due to their ease of synthesis, stable properties, and wide applicability. Compared to expensive inorganic supports, organic polymer supports are more flexible and inexpensive. However, addressing the issue of weak adhesion between the surface of the organic support and the ZIF-8 membrane layer poses a significant challenge. In this study, we present a strategy for preparation of ZIF-8 membrane by the fabrication of an asymmetric dual-layer polymeric hollow fiber support using polyvinylidene fluoride (PVDF) as the material. The outer layer of the support is composed of PVDF embedded with ZIF-8 seeds, while the inner layer consists of pure PVDF. This approach addresses the weak adhesion between the support and the ZIF-8 membrane layer formed through a one-step solvothermal crystallization process. The effects of ZIF-8 seed size, content, and crystallization conditions on the membrane structure and performance are investigated. Under the synergistic molecular sieving effects of ZIF-8 continuous membrane layer and ZIF-8 crystals within the outer layer of the support, larger gas molecules are difficult to penetrate the membrane layer, making the resulting membrane highly selective for the gas separation. Under the optimal fabrication conditions, the H2 permeability of the ZIF-8 membrane is determined to be 1.52 ± 0.1 × 10−7 mol·Pa−1·s−1·m−2, with a H2/N2 ideal separation selectivity of 69.5 ± 4. This method demonstrates simplicity and high reproducibility for preparation of ZIF-8 membranes on dual-layer hollow fibers, and it is expected to be extended to the growth and fabrication of other MOF membranes.

S vacancies engineering ZnIn2S4 nanosheets for boosted photocatalytic hydrogen evolution

2D-layered ZnIn2S4 nanosheets (ZIS NSs) have been considered as a promising photocatalysts to produce H2. Nevertheless, the carrier recombination of 2D ZnIn2S4 is still severe, which limits its photocatalytic efficiency and practical applications. Herein, the defective ZnIn2S4 nanosheets with S vacancies (DZIS NSs) is fabricated via an easy one-step solvothermal process only by changing the used solvent without a complex physical or/and chemical secondary treatment, which can realize efficient photocatalytic H2 generation. The resultant DZIS NSs show enhanced photocatalytic hydrogen evolution reaction (HER) activity and well stability after 5 cycles. And the photocatalytic HER rate of DZIS NSs is up to 5437 μmol−1 h−1 g−1, nearly 2.6 times of pristine ZIS NSs (2090 μmol−1 h−1 g−1). The experimental data suggest that the excellent photocatalytic HER performance of DZIS NSs is attributable to the existence of S vacancies, which can form a S defect energy level under the lower conduction band (CB), offering abundant active sites for hydrogen activation, extending the visible light absorption range and narrowing the bandgap of DZIS NSs. Such defect engineering strategy opens new avenues for other sulfide photocatalysts to further boost photocatalytic activity.

Construction of Novel Z-scheme Heterojunction in ZnFe2O4/P25 @ MOF-5 Nanocomposite from Plastic Waste for Efficient Photodegradation of Aqueous BTX Under Visible Light

AbstractAn innovative strategy to reduce water pollution is adsorption-assisted photocatalysis. A novel mesoporous heterogeneous adsorbent MOF-5-based photocatalysts were successfully synthesized by a green method from plastic waste through a one-step solvothermal process. Additionally, ZnFe2O4 nanocrystals were physically ground with commercial Degussa P25 at room temperature to prepare ZF/P nanocomposite catalysts. These catalysts demonstrated significant photocatalytic activity for the removal of BTX from wastewater. BTX was successfully degraded in an aqueous solution utilizing integrated adsorption and photocatalytic degradation using the newly developed ZF/P@MOF-5 samples with 0.01% of ZF/P. The in-depth characterization of the ZF/P@MOF-5 confirmed its positive physicochemical properties, such as porous nature, stability, high surface area, beneficial functional groups on its surface, and photocatalytic activity. PL spectroscopy also shows that the ZF/P-incorporated MOF-5 nanocomposite has a lower electron-hole recombination rate. The as-prepared ZF/P@MOF-5 mesoporous heterogeneous adsorbent-photocatalyst presented high adsorption and maximum degradation of BTX under visible radiations after 180 min. The reusability results demonstrated that 20 P/ZF @MOF-5 composite can be used effectively for up to four cycles, which makes the process more economical. This experimental study demonstrates that the novel ZF/P-incorporated MOF-5 is a potential route to producing photocatalysts for dissociating BTX wastewater that is highly effective, stable, economical, and sustainable.

Energy storage characteristics and mechanism of organic-conjugated polyanthraquinoneimide for metal-free dual-ion batteries

Organic materials have gained significant attention in the battery energy storage field due to their good reaction kinetics and designable properties. However, conventional organic materials typically exhibit poor cycling stability in dual-ion batteries because of their high solubility and low electron conductivity. Herein, an organic conjugated polyanthraquinoneimide (PAQI) with stacked layered porous nanosheet structures by a one-step solvothermal process. After polymerization, not only the solubility of PAQI in electrolytes was reduced, but also the utilization of the active site (C=O) was significantly increased to enhance the electronic conductivity. Moreover, PAQI also exhibited a high ion diffusion coefficient (0.946 × 10−10 ∼ 1.293 × 10−10 cm2 s−1) and showed excellent electrochemical performance as the anode for a metal-free dual-ion battery, with a discharge specific capacity of up to 128 mAh g−1 and a capacity retention rate of 80% after 200 cycles under a high rate of 2 C (1 C = 228 mA g−1). Meanwhile, cyclic voltammetry tests and reaction kinetic calculations revealed that PAQI was a pseudocapacitive storage mechanism combining diffusion control and surface capacitance processes (the capacitance contribution is 82.59 % at a scan rate of 0.9 mV s−1). These abundant stacked layered porous nanosheet structures provided a new route for research and development of the next-generation green metal-free dual-ion batteries.

Honeycomb-Structured MoSe2 /rGO Composites as High-Performance Anode Materials for Sodium-Ion Batteries.

Sodium-ion batteries are a promising substitute for lithium batteries due to the abundant resources and low cost of sodium. Herein, honeycomb-shaped MoSe2 /reduced graphene oxide (rGO) composite materials are synthesized from graphene oxide (GO) and MoSe2 through a one-step solvothermal process. Experiments show that the 3D honeycomb structure provides excellent electrolyte penetration while alleviating the volume change during electrochemical cycling. An anode prepared with MoSe2 /rGO composites exhibits significantly improved sodium-ion storage properties, where a large reversible capacity of 215mAhg-1 is obtained after 2700 cycles at the current density of 30.0Ag-1 or after 5900 cycles at 8.0Ag-1 . When such an anode is paired with Na3 V2 (PO4 )3 to form a full cell, a reversible specific capacity of 107.5mAhg-1 can be retained after 1000 cycles at the current of 1.0Ag-1 . Transmission electron microscopy, X-ray photoelectron spectroscopy and in situ X-ray diffraction (XRD) characterization reveal the reversible storage reaction of Na ions in the MoSe2 /rGO composites. The significantly enhanced sodium storage capacity is attributed to the unique honeycomb microstructure and the use of ether-based electrolytes. This study illustrates that combining rGO with ether-based electrolytes has tremendous potential in constructing high-performance sodium-ion batteries.

Enhanced Alkaline Hydrogen Evolution on Gd1.0/Ndx (x = 0.5, 1.0, 3.0, and 6.0%)-Doped TiO2 Bimetallic Electrocatalysts

The work reports a facile synthesis of high thermally stable nanocrystalline anatase TiO2 nanoparticles (NPs) doped with different atomic concentrations (0.5, 1.0, 3.0, and 6.0%) of Gd3+ and Nd3+ ions by a template-free and one-step solvothermal process, using titanium(IV) butoxide as a titanium precursor and dimethyl sulfoxide (DMSO) as a solvent. The structure and morphology of the Gd3+, Nd3+, and 0.5%Gd3+-0.5%Nd3+/doped TiO2 NPs have been characterized by using various analytical techniques. The Gd3+/ and Nd3+/TiO2 molar ratios were found to have a pronounced impact on the crystalline structure, size, and morphology of TiO2 NPs. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies revealed the proper substitution of Ti4+ by Gd3+ and Nd3+ ions in the TiO2 host lattice. The as-prepared Gdx/TiO2, Ndx/TiO2, and Gd1.0/Ndx/TiO2 bimetallic NPs, x = 0.5, 1.0, 3.0, and 6%, have been investigated as electrocatalysts for hydrogen evolution reaction (HER) in 1.0 M KOH solution using a variety of electrochemical techniques. At any doping percentage, the Gd1.0/Ndx/TiO2 bimetallic NPs showed higher HER catalytic performance than their corresponding counterparts, i.e., Gdx/TiO2 and Ndx/TiO2. Upon increasing the Nd content from 0.5 to 6.0%, the HER catalytic performance of the Gd1.0/Ndx/TiO2 bimetallic NPs was generally enhanced. Among the studied materials, the bimetallic Gd1.0/Nd6.0/TiO2 NPs emerged as the most promising catalyst with an onset potential of −22 mV vs. RHE, a Tafel slope of 109 mV dec−1, and an exchange current density of 0.72 mA cm−2. Such HER electrochemical kinetic parameters are close to those recorded by the commercial Pt/C (onset potential: −15 mV, Tafel slope: 106 mV dec−1, and exchange current density: 0.80 mA cm−2), and also comparable with those measured by the most active electrocatalysts reported in the literature. The synergistic interaction of Gd and Nd is thought to be the major cause of the bimetallic catalyst’s activity.

Outstanding photo-thermo synergy in aerobic oxidation of cyclohexane by bismuth tungstate-bismuth oxychloride high-low heterojunction

The difficulty of achieving both high conversion rate and high selectivity is a huge challenge in the catalytic aerobic oxidation of cyclohexane. In this paper, bismuth tungstate-bismuth oxychloride (Bi2WO6-BiOCl) nanoflower heterojunctions prepared via a one-step solvothermal process were applied in the photo-thermo synergetic catalytic oxidation of cyclohexane in the dried air. With the addition of little water at different reaction temperature, the ratio of bismuth to tungsten and the mass ratio of Bi2WO6 to BiOCl can be precisely tailored in the nanoflower sphere composites with thin nanosheets. Their microscopic morphology, elemental composition, crystal structure, and photoelectrochemical characteristics were explored by different characterization methods. The Bi2WO6-BiOCl composites possessed poor photocatalytic and thermal performances with the low conversion rates of 1.43% and 2.68%, respectively. However, through the photo-thermo catalytic oxidation process, an exceptional conversion rate of 13.32% was achieved with excellent selectivity of 99.22% for cyclohexanone and cyclohexanol (KA oil) using the same Bi2WO6-BiOCl composites. This superior performance outstrips Bi2WO6 flowers, BiOCl nanosheets and Bi2WO6-BiOCl composites with other compounding ratios. The creation of a high-low heterojunction in the Bi2WO6-BiOCl composite was confirmed by band energy analysis. The opto-electronic analysis, band energy analysis, sacrifice experiments, and active radical analysis were employed to elucidate the mechanism for the exceptional photo-thermo catalytic performance in detail. This work offers an exploratory solution to the challenges of high energy consumption and the difficulty in simultaneously achieving high selectivity and high conversion rates in cyclohexane oxidation, thus holding significant value.