Template-assisted Method Research Articles

Boosting the potassium storage property of spongia-like copper phosphide anode via nano-in-micro construction

Metal phosphides (MPs) show great promise as anode material in potassium-ion batteries (PIBs) owing to their cost-effectiveness and high theoretical capacity. Despite that, MPs anode usually manifests inferior poor cyclability as a result of dramatic volume fluctuation during discharge–charge cycling. Herein, a scalable salt template-assisted spray-drying method is developed to fabricate the porous carbon microspheres wrapped CuP2 nanoparticles (p-CuP2/C) with a nano-in-micro structure. The combination of the CuP2 nanoparticles, large meso-porous carbon microspheres can simultaneously offer plenty of reactive sites, promote electrolyte penetration, and maintain structural integrity. Additionally, the proposed synthesis strategy is suit for the industrial manufacture. As an anode for PIBs, the p-CuP2/C anode presents a high reversible capacity (494 mAh/g at 0.05 A/g), excellent cycling stability (a capacity degradation rate of 0.04 % per cycle during 2000 cycles at 2 A/g), and superior rate capability (244 mAh/g at 2 A/g). More impressively, pairing with a potassium Prussian blue cathode, the potassium-ion coin cell shows an excellent cycling lifespan with 87.1 % capacity retention after 200 cycles at a current density of 0.1 A/g, the assembled pouch cell also maintains stable cycling at 0.3 A/g over 80 cycles. This research could offer a facile approach to develop other advanced anodes with industrial practicability for alkali ion batteries.

Template-assisted fabrication of PVK microwire arrays for high-performance flexible photodetectors

The development of flexible photodetectors is crucial for advancing wearable electronics and optoelectronic systems, but it faces significant challenges, such as maintaining high performance under mechanical strain and achieving cost-effective fabrication. Here, we fabricated a photodetector using poly(N-vinylcarbazole) (PVK) microwire arrays through a template-assisted method. The resulting devices exhibit high responsivity and exceptional mechanical flexibility, with the ability to maintain their photoelectric properties even when bent up to 150°. The photodetector exhibits high responsivity of 0.9 A W−1 and detectivity of 1.6 × 1010 Jones. This study demonstrates the potential of PVK microwire arrays for imaging applications, highlighting their suitability for integration into flexible and wearable devices.

Preparation of highly hydrophilic cesium ion sieve and its performance in adsorbing Cs+

The unique properties of cesium compounds have garnered increasing attention, among which Cs2Ti6O13 shows great potential for applications. This paper synthesized Cs2Ti6O13(CTO-3) using a template-assisted solvothermal method with cesium carbonate as the cesium source and tetrabutyl titanate as the titanium source. Among them, F127 and hexadecylamine are used as template agents to modulate the surface morphology and hydrophilicity of the precursor. The cesium ion sieve H2Ti6O13 (HTO-3) synthesized after hydrochloric acid pickling has a large specific surface area and good hydrophilicity. This structure is conducive to the ion exchange between Cs+ and H+, resulting in a fast adsorption rate. It is completed within 2 h, and the adsorption capacity reaches 360 mg/g, which is significantly greater than that of the traditional high-temperature solid-phase method. The adsorption process of Cs+ on HTO-3 is more consistent with the pseudo-second-order kinetic equation model, and the adsorption process is chemical adsorption. HTO-3 exhibited good selectivity and cycle stability. At the fifth time of the adsorption-resolution cycle, the adsorption capacity was 87.1 % of the first time.

Bi-reforming of model biogas to syngas over ultrasmall Ru/MgO nano-catalysts prepared via soft template-assisted mechanochemical method

The upgrading of renewable biogas into value-added fuel and chemicals via syngas is of great significance. Ru/MgO nano-catalysts were prepared via novel soft template-assisted mechanochemical method. Comprehensive characterizations (XRD, N2 physisorption, ICP-OES, CO-chemisorption, CO2-TPD, XPS, HAADF-STEM, HRTEM, CH4-TPSR/CO2-TPO, TGA and Raman spectroscopy, etc.) were conducted to deeply analyze the fresh/spent catalysts. The 0.2Ru/MgO-0.2CTAB catalyst showed high initial activity in terms of CH4/CO2 conversion (∼94 %/61 %) and maintained catalytic stability over 120 h in bi-reforming of model biogas, at 800 °C under CH4/CO2/N2/H2O molar ratio of 3:2:1:2.6 and weight hourly space velocity of 30960 mL g-1h−1. CTAB and other soft templates were effective in enhancing the dispersion of Ru nanoparticles (NPs), which contribute to the inhibition of the deep cracking of CH4 and coke accumulation. Alkaline MgO oxide was crucial in the activation of CO2 and the production of active O* species, thus promoting the removal of carbonaceous precursor and inhibiting the coke accumulation. Additionally, the strong interaction between ultrafine Ru NPs and the MgO support significantly contributed to its anti-sintering performance. The combined advantages of narrow size distribution of ultra-small Ru NPs, suitable basicity of MgO as well as the interaction between ultrafine Ru NPs and MgO over 0.2Ru/MgO-0.2CTAB catalyst led to satisfying catalytic performance in bi-reforming of model biogas.

Predesigned perovskite crystal waveguides for room-temperature exciton-polariton condensation and edge lasing.

Perovskite crystals-with their exceptional nonlinear optical properties, lasing and waveguiding capabilities-offer a promising platform for integrated photonic circuitry within the strong-coupling regime at room temperature. Here we demonstrate a versatile template-assisted method to efficiently fabricate large-scale waveguiding perovskite crystals of arbitrarily predefined geometry such as microwires, couplers and splitters. We non-resonantly stimulate a condensate of waveguided exciton-polaritons resulting in bright polariton lasing from the transverse interfaces and corners of our perovskite microstructures. Large blueshifts with excitation power and high mutual coherence between the different edge and corner lasing signals are detected in the far-field photoluminescence, implying that a spatially extended condensates of coherent polaritons has formed. The condensate polaritons are found to propagate over long distances in the wires from the excitation spot and can couple to neighbouring wires through large air gaps, making our platform promising for integrated polaritonic circuitry and on-chip optical devices with strong nonlinearities.

Influence of iron doping in mesoporous ceria on the physicochemical properties and catalytic activity in styrene oxidation

A series of nanosized Fe-Ce binary oxides (2, 5, 10, 20, and 30 wt% Fe) and pure oxides of Fe and Ce were prepared by the template-assisted coprecipitation method and evaluated for styrene oxidation. The synthesised binary oxides were investigated by Powder X-ray diffraction(PXRD), N2-physisorption, X-ray fluorescence (XRF), Field emission scanning electron microscopy (FE-SEM), Highresolutiontransmission electron microscopy (HR-TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Ultraviolet–Visiblediffuse reflectance spectroscopy (UV–Vis DRS), X-ray photoelectron spectroscopies (XPS), and Hydrogen-temperature programmed reduction (H2-TPR). In particular, the influence of quantity of doped iron on the structure, phase composition, surface morphology, reducibility, and the catalytic performance of ceria is deeply investigated. All the synthesized Fe-doped ceria catalysts exhibited the formation of solid solutions, but a little α-Fe2O3 segregated on the surface of ceria at 20 and 30 wt% Fe doped ceria. Among all Fe-Ce binary oxides, the 10 wt% Fe-doped ceria catalyst demonstrated superior efficiency due to its optimal Fe content which achieved the high surface area, lattice oxygens, reducibility, and low crystallinity, as confirmed by BET (Brunauer-Emmett-Teller) measurements, XPS, H2-TPR and powder XRD analysis, respectively. To optimize the reaction conditions, effect of several experimental variables, such as reaction temperature, duration, catalyst quantity, styrene/tert-Butyl hydroperoxide (TBHP) mole ratio, and solvent polarity were investigated. Furthermore, the catalyst stability and consistent activity were confirmed by testing six reusability cycles.

Highly dispersed Ni nanoparticles confined in mesoporous SBA-15 for methane dry reforming with improved coke resistance and stability

Methane dry reforming (DRM) is a promising route for sustainable syngas production, in which Ni-based catalysts face challenges of metal sintering and coke formation. In this work, highly dispersed Ni nanoparticles (NPs) embedded in the mesopores of SBA-15 were prepared using a simple solid-state impregnation (SSI) method. TEM and cross-section HRTEM results clearly indicated that ultra-small Ni NPs (3–4 nm) were orderly dispersed within the mesopores of the SBA-15 support. Compared with the conventional wetness impregnation (WI) method, the Ni/SBA-15 catalyst prepared by solid-state impregnation method possessed much better catalytic activity, stability, and coke resistance in DRM. In-situ DRIFTS and semi-in-situ XRD were used to elucidate the dispersion and encapsulation mechanism of Ni within the mesopores of SBA-15 during the sample preparation process. Specifically, WI formed large NiO particles, while SSI formed smaller NiO NPs with stronger interaction between metal and support (SIMS) via forming Ni-O-Si species which is beneficial for the DRM reactivity. This work establishes relationships among catalyst preparation, structure, and DRM performance, paving the way for general template-assisted methods to prepare nanometallic catalysts for various applications.

Ultrasensitive carbon nanotube-bridged MXene conductive network arrays for one-step homogeneous electrochemical immunosensing of tumor markers

Developing non-passivating and fully integrated electrode arrays for point-of-care testing of carcinoembryonic antigen (CEA) is crucial, as the serum level of CEA is closely associated with colorectal cancer. Herein, we propose a simple, low-cost, and eco-friendly template-assisted filtration method for the scalable preparation of carbon nanotube-bridged Ti3C2Tx MXene (MX@CNT) electrode arrays with a conductive network. Furthermore, we fabricate a homogeneous electrochemical (HEC) sensor for CEA detection by integrating a magnetic-bead-based alkaline phosphatase-linked immunoassay (MB-aElisa), which enables the in-situ generation of the electroactive substance 1-naphthol (1-NP). Benefiting from the unique electrochemical characteristics of a MX@CNT electrode array, such as ultra-low background signal and superior electrocatalytic activity towards the hydrolyzed 1-NP, the MB-aElisa-based HEC sensor specifically measures CEA within a detection range spanning from 0.005 to 1.0 ng mL−1, achieving a detection limit of 1.6 pg mL−1. Subsequently, this biosensing prototype is successfully utilized for the detection of CEA in serum specimens obtained from colorectal cancer patients. More importantly, the integration of MB-aElisa with a MX@CNT electrode array not only marks a significant advancement but also enables the creation of a one-step homogeneous electrochemical immunosensing platform, serving as a paradigm for the highly sensitive and selective measurement of trace tumor markers in complex biological samples.

Perovskites synthesized by soft template-assisted hydrothermal method: A bibliometric analysis and new insights

Hydrothermal synthesis is a technique which enables preparing many perovskites with specific crystal structures, chemical compositions, and morphologies. Thus, a bibliometric analysis of 1087 articles from the Scopus database (1975–2023) related to the keywords “perovskites” and “hydrothermal synthesis” was conducted using the VOSviewer software program. The results of the bibliometric analysis showed that the 1087 articles have 23,286 citations. Materials Letters has the highest number of publications (2.85%) regarding the journals in which these articles are published. China has the highest number of publications (34.50%) and citations (33.56%) related to these articles. Regarding the institutions affiliated with these articles, Jilin University in China concentrates 5.34% of the publications and 6.08% of the citations. In terms of authors, Han, G. has the highest number of publications (2.02%). Finally, the top three keywords with the highest number of occurrences were “perovskite”, “hydrothermal synthesis” and “scanning electron microscopy”. Based on bibliometric analysis, LaNiO3 perovskites were chosen to evaluate the influence of hydrothermal synthesis parameters on their morphologies and, consequently, how these morphologies affect their applications. Thus, the temperature and time ranges used for the synthesis parameters were 160–230 °C and 6–48 h, respectively. Furthermore, the pH range used was 7.6–13, and the mineralizers used to adjust the pH were ammonia, potassium hydroxide, and sodium hydroxide. The temperature and time ranges used for the calcination parameters were 550–800 °C and 2–6 h, respectively. Additionally, LaNiO3 perovskites obtained sphere, cube, rod, disc, and hollow morphologies. The soft templates used to obtain these morphologies were glycine, glycerin, isopropanol, polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), citric acid, and urea. The specific surface areas of the perovskites varied between 5.2 and 35.8 m2 g−1. Finally, the most common application for LaNiO3 perovskites was the methane reforming for hydrogen production.

Highly responsive double-shell ZnO hollow microspheres based gas sensor for acetic acid detection in vinegar

Acetic acid sensing materials for environmental and related food quality control requiring high sensitivity and selectivity, and ppb-level detection limit, remain challenging. Double-shell ZnO hollow microspheres were prepared by a surfactant assisted template method, and the resultant gas sensor showed excellent acetic acid sensing performance. The sensor response reached 116 to 100 ppm acetic acid at 270°C with a short response time of 3.2 s. The relationship between acetic acid concentration and the response was established, and the detection limit reached 100 ppb. DFT theory computational results demonstrated the highest adsorption energy of the ZnO gas sensor to acetic acid among all tested gases, proving its high selectivity to acetic acid. Besides, the unique double-shell hollow structure with abundant oxygen vacancy and large surface area might be the other factors that gave rise to its excellent acetic acid gas sensing performance. Based on the gas sensor, a method for fast quantitative detection of acetic acid content in vinegar was developed. The linear relationship between sensor response and acetic acid gas concentration of vaporized white vinegar was established, and the acetic acid content in the vinegar can be quickly determined. The result proved our acetic acid sensor to be a promising candidate for practical applications.

Traditional Chinese Medicine Integrated Multifunctional Responsive Core-Shell Microneedles for Dermatosis Treatment.

Microneedles have demonstrated value in targeted treatment of dermatosis. Current investigation aims to enhance the functions and optimize substance delivery to improve therapeutic effects. Here, we present innovative shell-core microneedles with light-pH dual responsiveness for spatiotemporal sequential release of multiple Chinese herb drugs to treat scleroderma. By using a stepwise template-assisted method, we effectively prepare a hydrogel-based core layer containing polydopamine-MXene (P-MXene) loaded with triptolide (TP), and a shell layer composed of polyvinyl alcohol (PVA) encapsulating paeoniflorin (Pae). P-MXene can adsorb the sparingly soluble TP to ensure its encapsulation efficiency and contribute to the synergistic photothermal effect benefitting from its excellent photothermal conversion ability. Besides, PVA can rapidly dissolve upon microneedle piercing into the skin and quickly release the anti-inflammatory and detoxifying Pae, establishing a favorable low-acid subcutaneous environment. In response to pH changes and near-infrared effects, TP is sustainably released from P-MXene and delivered through the swollen pores of the hydrogel. On the basis of these characteristics, we demonstrate that these microneedles could effectively reduce profibrotic key cytokines interleukin-1β and transforming growth factor-β, thereby reducing collagen deposition and decreasing epidermal thickness, ameliorating skin fibrosis and capillary lesion in scleroderma mouse models. These findings highlight the important clinical potential of these microneedles in the treatment of skin diseases.

Small animal PET imaging with the 68Ga-labeled pH (low) insertion peptide-like peptide YJL-4 in a triple-negative breast cancer mouse model

BackgroundThe aim of this study was to prepare a novel 68Ga-labeled pH (low) insertion peptide (pHLIP)-like peptide, YJL-4, and determine its value for the early diagnosis of triple-negative breast cancer (TNBC) via in vivo imaging of tumor-bearing nude mice. The novel peptide YJL-4 was designed using a template-assisted method and synthesized by solid-phase peptide synthesis. After modification with the chelator 1,4,7‑triazacyclononane-N,N′,N″-triacetic acid (NOTA), the peptide was labeled with 68Ga. Then, the biodistribution of 68Ga-YJL-4 in tumor-bearing nude mice was investigated, and the mice were imaged by small animal positron emission tomography (PET).ResultsThe radiochemical yield and radiochemical purity of 68Ga-YJL-4 were 89.5 ± 0.16% and 97.95 ± 0.06%, respectively. The biodistribution of 68Ga-YJL-4 in tumors (5.94 ± 1.27% ID/g, 6.72 ± 1.69% ID/g and 4.54 ± 0.58% ID/g at 1, 2 and 4 h after injection, respectively) was significantly greater than that of the control peptide in tumors at the corresponding time points (P < 0.01). Of the measured off-target organs, 68Ga-YJL-4 was highly distributed in the liver and blood. The small animal PET imaging results were consistent with the biodistribution results. The tumors were visualized by PET at 2 and 4 h after the injection of 68Ga-YJL-4. No tumors were observed in the control group.ConclusionsThe novel pHLIP family peptide YJL-4 can adopt an α-helical structure for easy insertion into the cell membrane in an acidic environment. 68Ga-YJL-4 was produced in high radiochemical yield with good stability and can target TNBC tissue. Moreover, the strong concentration of radioactive 68Ga-YJL-4 in the abdomen does not hinder the imaging of early TNBC.

PBA-Derived Heteroatom-Doped Mesoporous Graphitic Spheroids as Peroxidase Nanozyme for In Vitro Tumor Cells Detection.

Inspired by the two kinds of naturally occurring peroxidases (POD) with vanadium or heme (iron)-based active catalytic centers, we have developed a dual metal-based nanozyme with dual V and Fe-based active catalytic centers. Co-doping of graphene with heteroatoms has a synergistic effect on the catalytic properties of the nanomaterial as the distances of migration of the substrates drastically reduce. However, a few studies have reported the codoping of heterometallic elements in the graphene structure due to the complexity of the synthesis procedures. Herein, we report the synthesis of in situ doped bimetallic VNFe@C mesoporous graphitic spheroids nanozyme via pyrolysis without the assistance of any template assisted method. The Prussian-blue analog-based precursor material was synthesized by a facile one-step low-temperature synthesis procedure. The bimetallic spheroids showed an excellent affinity toward H2O2, with a Km value of 0.26 mM when compared to 0.436 for the natural POD, which is much better than the natural POD, which was utilized to detect tumor cells in vitro through the intracellular H2O2 produced by these cells under high oxidative stress. The VNFe@C mesoporous spheroids generate dual reactive oxygen species, including the •OH and •O2H- radicals, in the presence of H2O2, which are responsible for the POD-like activity of these nanozymes, while the bimetallic V/Fe doping plays a synergistic role in the enhancement of the activity of codoped graphitic spheroids.

Study on the flow characteristics of microscale copper inverse opal wick structures

Ultra-thin heat pipes are extensively used to address heat dissipation challenges in compact electronic devices with limited space. Research on new types of micro-porous wick is crucial for enhancing the heat transfer of ultra-thin heat pipes. The hydraulic transport properties of micro-porous wick structures are crucial factors for the applications. The inverse opal (IO) micro-porous metal structure has gained extensive attention for its ordered periodic arrangement and high porosity characteristics. In the paper, the copper inverse opal (CIO) and gradient CIO are fabricated by a template-assisted deposition method. Experimental measurements are conducted to study the fluid ascent process within the CIO structure. In addition, a face-centered cubic geometric model is established based on the structure information obtained by a scanning electron microscope (SEM). The calculation employs a porous media model and takes into account the resistance characteristics in the initial phase. The relative error between the simulation and experimental results is less than 7.7%. Furthermore, the fabricated gradient CIO structure is uniform and exhibits a higher permeability than single-pore CIO. The permeability of this gradient CIO is about 1.9–3.2 × 10−14 m2. Understanding the microscopic liquid transport process within CIO structures is of great importance in the selection and optimization of capillary wick structures.

Encapsulating Sulfur into a Gel-Derived Nitrogen-Doped Mesoporous and Microporous Carbon Sponge for High-Performance Lithium-Sulfur Batteries.

The practical application of Li-S batteries (LSBs) has long been impeded by the inefficient utilization of sulfur and slow kinetics. Utilizing conductive carbonaceous frameworks as a host scaffold presents an efficient and cost-effective approach to enhance sulfur utilization for redox reactions in LSBs. However, the interaction of pure carbon materials with lithium polysulfide intermediates (LiPSs) is limited to weak van der Waals forces. Hence, the development of an economical method for synthesizing heteroatom-doped carbon materials for sulfur fixation is of paramount importance. In this study, we introduce a hierarchical porous nitrogen-doped carbon sponge (NPCS) with an exceptionally high BET surface area of 3182.2 m2 g-1, achieved through a facile template-assisted polymerization method. The incorporation of inorganic salts, free radical polymerization, and deuteric freeze-drying techniques facilitates the formation of hierarchical pores within the NPCS. After sulfur fixation, the resulting S/NPCS electrode demonstrates remarkable electrochemical performance in LSBs. Specifically, it achieves an 80% sulfur utilization rate, maintains a high reversible specific capacity of 400 mA h g-1 even after 600 cycles at a demanding current density of 5.0 A g-1, and exhibits superior rate capability. It is believed that this work will inspire the rational design of cost-effective carbon-based electrodes for high-performance LSBs.

A template-assisted method for synthesizing TiO2 nanoparticles and Ni/TiO2 nanocomposites for urea electrooxidation

The exploration of electrocatalytic urea-assisted wastewater treatment as a method for sustainable energy generation presents a compelling approach within the domain of green chemistry. In this context, titanium dioxide (TiO2) and nickel-doped TiO2 (Ni@TiO2) nanocomposites were developed through an innovative organic template-assisted synthesis strategy. These were denoted as m-TiO2-org and Ni@m-TiO2-org, respectively, to create cost-effective and high-performance electrodes for urea electrooxidation in urea-based fuel cells. The structural and chemical properties of the fabricated m-TiO2-org and Ni@m-TiO2-org materials were meticulously analyzed using a suite of physicochemical characterization techniques, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Energy-Dispersive X-ray Spectroscopy (EDX). These investigations revealed that both m-TiO2-org and Ni@m-TiO2-org materials predominantly consisted of irregular monolithic microparticles formed through the aggregation of spherical nanoparticles, with diameters ranging from 8.16 nm to 13.1 nm. Subsequent evaluations of these TiO2-based materials as electrocatalysts for urea electrooxidation demonstrated their efficacy, as evidenced by voltammetric and electrochemical impedance spectroscopy measurements. Notably, the Ni@m-TiO2-org variant exhibited enhanced electrochemical performance, attributed to the presence of Ni2+ sites. These sites facilitated electrochemical activation and the formation of active NiOOH sites, leading to a significant increase in the current density (0.78 mA/cm2 at 1.523 V vs. the Reversible Hydrogen Electrode (RHE)), as a fiftyfold enhancement compared to m-TiO2-org@Glassy Carbon Electrode (GCE) under similar conditions (3 M KOH containing 3 M urea), with a Tafel slope of 33 mV/decade. This research not only elucidates the potential of TiO2-based nanocomposites in the electrooxidation of urea but also heralds the development of innovative electrode materials for commercial electrochemical cells, marking a significant advancement in the field of electrocatalysis and sustainable energy technology.

Assisted Self-Assembly of Nanoporous Ices via Carbon Nanomaterial Templates.

Self-assembly is a widely used synthetic method in nanoscience to assemble well-organized structures. Self-assembly processes usually occur in a water solvent environment. However, the self-assembly of water molecules is rarely studied. Herein, we show a strategy to fabricate porous ice via carbon nanomaterial-assisted self-assembly. Diverse frameworks of nanoporous ice are formed by using orthorhombic and tetragonal arrays of carbon nanotubes or carbon-atom chains as templates. In contrast to many bulk ices discovered in nature, nanoporous ices are shown to be stable only under negative pressure. Hence, nanoporous ices cannot be produced through the direct nucleation of water at negative pressure. The template-assisted self-assembly method is shown to be the most effective method to fabricate nanoporous ice in quantity. Several key factors for the self-assembly of nanoporous ices are identified, including proper gap spacings in the carbon nanomaterial template and suitable interactions between water and the carbon nanomaterials.

The tellurium-induced CoSe polyhedral porous nano-structured materials as high-performance cathodes for rechargeable magnesium batteries

Rechargeable magnesium batteries (RMBs) are cost-effective and dendrite-free, making them desirable for large-scale applications. Nevertheless, the exploration of high-performance cathodes still remains a great challenge in magnesium battery research. Herein, the CoSe porous polyhedra induced by Te heteroatoms (CoSe/Te) are successfully prepared by two-step metal-organic framework (MOF)-template assisted method and investigated as high-efficiency cathodes for rechargeable MIBs. In this regard, the affluent porous structure can facilitate the transport of Mg2+ ions while the introduction of Te heteroatoms can reduce the conversion reaction barrier, boost the kinetics and redox reversibility and excite the electron conduction to build active nanostructured domains for highly reversible Mg storage reactions. As a consequence, the CoSe/Te maintains the high specific capacity of 150.6 mAh g−1 after 600 cycles at 200 mA g−1, with a superior capacity retention rate of 75.3%. Moreover, the specific capacity of such electrode materials changed from 260 mAh g−1 to 41 mAh g−1 when the current density increased from 100 mA g−1 to 2000 mA g−1, and gradually recovered to 256.5 mAh g−1 when the current density returned to 100 mAh g−1, exhibiting a better rate performance. This work highlights how micro-nanostructures can favor magnesium storage reaction reversibility and cyclability and also provide insights into rational electrode design for storing magnesium cations in future studies.

Elevating hydrogen evolution performance with plasma-induced sulfur vacancies and heteroatom doping in hollow-structured MnS–CoS catalysts

Transition-metal sulfides doped with various elements show great promise as highly effective catalysts for the hydrogen evolution reaction (HER), potentially serving as alternatives to Pt-based electrocatalysts. Defect engineering has been identified as a key strategy to enhance the HER activity of such catalysts. This study proposes an effective strategy to generate numerous topological/geometric defects on hollow spherical Mn-doped cobalt sulfide (MnS–CoS) via plasma etching. MnS–CoS catalysts with well-defined cavity structures were successfully prepared using a combination of template-assisted and hydrothermal synthesis methods. Under plasma induction, these catalysts exhibited uniformly formed nanocavity structures with a built-in electric field, which uniformly enhanced their topological/geometric defect levels. The plasma-etched MnS–CoS catalyst demonstrated significantly enhanced HER activity, exhibiting an excellent overpotential of 172 mV at a current density of 10 mA·cm⁻2 in alkaline media and a low Tafel slope of 120 mV·dec⁻¹. These improvements can be attributed to the remarkable conductivity of Co and Mn, along with the unique hollow spherical nanostructure of the material, which contained numerous gaps that promoted electron movement and electrolyte penetration, thereby enhancing the overall catalytic performance. The synergistic effects of heteroatom doping and plasma modulation played a crucial role in achieving outstanding catalytic performance toward the HER. Density-functional theory calculations based on a structural model of MnS–CoS-p confirmed that the introduction of defects and heteroatoms reduced hydrogen adsorption: the Gibbs free energy decreased from 0.72 eV for CoS to 0.23 eV for MnS–CoS-p. The excellent HER activity of the MnS–CoS materials stemmed from the abundance of reactive heterostructured interfaces, which optimized the electronic configuration and, thus, accelerated H2O adsorption and dissociation. This study highlights the potential of combining plasma-assisted defect manipulation and transition-metal-element doping to design high-performance catalysts. The findings also offer valuable insights into the development of environment-friendly energy-conversion technologies.

Template-assisted synthesis of 3D ordered mesoporous graphitic carbon nitride decorated with gold nanoparticles for dopamine sensing

Three-dimensional mesoporous graphitic carbon nitride (Au/3Dom CN) decorated with a gold nanoparticle composite was successfully prepared via a template-assisted method using Au–SiO2 nanospheres as sacrificial agents.