ChemNanoMat最新文献

Direct ethanol fuel cells have attracted significant attention due to their high energy density, environmental friendliness, fuel availability, and low toxicity. However, their broader application is constrained by the anode catalyst limitations such as low active site density and low stability caused by the CO* intermediate poisoning. In this work, Pd metallene was synthesized via a hydrothermal method, and transition metal Cu was introduced to obtain PdCu bimetallene supported with porous Cu nanoparticles (NPs). The results indicate that the unique configuration of Cu not only enhances the CO* intermediate tolerance of Pd through electronic interactions but also leverages the intrinsic catalytic activity of Cu, leading to a further improvement in catalytic performance. Therefore, the designed PdCu bimetallene/Cu NPs exhibits a high mass activity of 1.26 A mg_Pd⁻¹ for the ethanol electro oxidation reaction, which is 8.4 times that of commercial Pd/C and superior to recently reported Pd-based catalysts. In addition, it maintains a current density of 7.87 mA cm⁻² after a 3000 s stability test, demonstrating considerable potential for practical applications. This work provides feasible ideas for the microstructure design and electronic control optimization of metallene in small molecule catalysis.

Organic–inorganic hybrid manganese(II) halide materials have attracted attention for their stimuli-responsive luminescence switching, making them promising candidates for anticounterfeiting applications. Furthermore, these materials have also emerged as efficient scintillators due to their remarkable X-ray absorption properties. Herein, we developed a novel zero-dimensional manganese(II) halide, (pr-ted)₂MnBr₄·H₂O (pr-ted = 1-propyl-1,4-diazabicyclo[2.2.2]octan-1-ium), which exhibits water-molecule-induced reversible photoluminescence transformation. Specifically, thermal dehydration of (pr-ted)₂MnBr₄·H₂O induces a structural transition to anhydrous (pr-ted)₂MnBr₄, accompanied by a distinct emission color change from red to green. Remarkably, the original hydrated phase can be fully restored upon re-exposure to moisture, demonstrating excellent reversibility. Based on this unique property, we successfully applied (pr-ted)₂MnBr₄·H₂O in information encryption–decryption, optical anticounterfeiting, and optical logic gate. Additionally, both (pr-ted)₂MnBr₄·H₂O and (pr-ted)₂MnBr₄ exhibit outstanding scintillation performance, with measured light yields of 30,120 photons MeV⁻¹ and 26,320 photons MeV⁻¹, respectively. This work provides a strategic approach for designing multifunctional manganese(II) halide materials.

Lemna minor is an aquatic plant with a high growth rate, which can cause problems in freshwater bodies. In this work, Lemna minor was valorized for the development of bifunctional electrocatalysts for rechargeable and flexible zinc–air batteries (FZABs), by synthesizing cobalt-doped and cobalt–manganese co-doped electrocatalysts (L-Co and L-CoMn). Raman spectroscopy revealed structural disorder, particularly in L-Co, which was further confirmed by TEM and attributed to a high density of surface defects. Moreover, TEM and STEM imaging indicated the formation of both spinel nanoparticles and atomically dispersed metal sites, which together with surface defects, contributed to the electrocatalytic activity. Electrochemical tests showed that L-Co exhibited superior activity in the oxygen reduction reaction, while L-CoMn demonstrated enhanced activity for the oxygen evolution reaction, achieving a low overpotential of 1.56 V at 10 mA cm⁻². When used as bifunctional electrocatalysts in FZABs, the L-Co presented better performance, higher cycling stability (>100 cycles), and improved capability to operate at elevated current densities, while achieving an areal specific capacity of 14.7 mA.h cm⁻². These results demonstrate the potential of Lemna minor valorization for applications in electrochemical and sustainable energy technologies.

Carbon materials are widely used as supports in heterogeneous catalysis. They offer high conductivity, thermal and chemical stability, as well as a desirable porous structure that enables the use of their surface to anchor catalytically active sites. The distribution of metals within a carbon matrix enables a higher dispersion of active sites, stabilizing the atoms or nanoparticles, while ideally increasing the activity per unit mass of metal present. Investigating the synergistic combination of a metal source deposited onto different carbon materials provides a guideline for selecting support materials in catalyst design. In this work, carbons with various pore size distributions, including DUT-108, a commercial activated carbon (ACC), and Ketjen Black EC-600 JD, were investigated as supports for an iron–based complex, Fe(II) tris-1,10-phenanthroline sulfate, incorporated via incipient wetness impregnation followed by pyrolysis. The resulting iron-doped carbon catalysts were evaluated in the oxygen reduction reaction (ORR) in alkaline media. Pore size distribution, structural descriptors, iron, and nitrogen content reveal correlations of activity, morphology, and surface chemistry. Ketjen Black was found to be the best support among the carbons investigated, resulting in a more positive onset potential, high selectivity toward the 4e^– pathway, and twice the limiting current density compared with other carbons.

All-inorganic CsPbX₃ quantum dots combine high efficiency, narrow emission, and solution processability , however, their scalable full-color implementation requires pixel-level patterning with minimal performance loss. Herein, we developed a spray-driven halide exchange strategy that enabled spatially programmable color tuning and patterning of green CsPbBr₃ films. By spraying a chlorine-based ligand through a mask, we obtained a surface-confined Br → Cl exchange, creating precise patterns without reprocessing the underlying film. After ligand exchange with phenethylammonium chloride (PEACl) at various concentrations, the photoluminescence peak shifted from 516 to 495/462/433 nm, while maintaining a full width at half maximum of approximately 20 nm. In addition, the crystalline phases and surface morphologies of the films were preserved. Furthermore, devices fabricated from halide exchange-treated films successfully converted the emission from green to blue. This strategy achieved an engineering tradeoff between pronounced color tuning and limited efficiency loss, providing a practical route for full-color pixelation on a single substrate.

The catalytic oxidation of toluene holds considerable theoretical and practical importance for the improvement of air quality and the safeguarding of human health. Nevertheless, enhancing the efficiency of toluene oxidation continues to pose a significant problem to be overcome. Recently, morphology optimization and bimetallic strategy have emerged as the most effective approaches for enhancing catalytic performance. Herein, variety of CoCu oxide catalysts with a spinel nanoflower structure were fabricated using a solvent thermal method combined with a sodium borohydride reduction process. Among the catalysts examined, the CoCuO-5 catalyst demonstrates superior morphology and catalytic activity. This was caused by the advantageous morphology of the nanoflower and the synergistic effects arising from the combination of Cu and Co components. The emergence of nanoflower structures significantly enhances the specific surface area following reduction, thereby facilitating an improvement in catalytic activity. Cu is introduced into the system increases the concentration of oxygen vacancy and accelerates the redox cycle of Co²⁺/Cu²⁺ ↔ Co³⁺/Cu⁺. This work exhibits a prospective strategy for the degradation of volatile organic compounds found in atmospheric pollutants.

Lithium–sulfur batteries (LSBs) are an interesting new energy storage alternative because of their high capacity (1675 mAh g⁻¹), low manufacturing costs, and the high availability of sulfur. Still, even with great progress, certain issues like poor sulfur conductivity, the loss of elemental sulfur and movement of lithium polysulfides (LiPSs), and extreme volume expansion make them unsuitable for mass production. This review offers a comprehensive, up-to-date roadmap through state-of-the-art cathode designs, focusing on how recent advances in porous carbon hosts, doped and defect-engineered graphene, and robust metal-based compounds have progressively overcome core bottlenecks by combining electron/ion conduction, physical confinement, and strong chemical binding. The detail progression from early carbon-based hosts often limited by weak polysulfide retention and sluggish redox kinetics to modern composite frameworks that integrate hierarchical porosity, heteroatom doping, and catalytic interfaces, sharply improving cycle life and reversible capacity at realistic sulfur loadings. Metal-based hosts and hybrid materials, including transition metal sulfides, oxides, and single-atom catalysts, are shown to greatly accelerate redox chemistry. The review demonstrates that individual strategy fails to solve all challenges associated with LSBs so it supports integrated design which combines chemistry with structural engineering and computational innovations to create complete solutions. We discuss the transformative role of in situ and operando characterization, machine learning, and open data benchmarking, which now make it possible to quickly identify and optimize hosts, understand mechanisms, and push LSBs toward commercial requirements. Special attention is given to emerging material classes like high-entropy alloys and covalent organic frameworks, as well as to sustainable design and recycling. By connecting innovations in materials, architecture, and advanced analytics, this review not only summarizes the latest scientific progress, but also identifies the shared strategies likely to drive LSBs from continued hype to practical deployment in real-world applications.

Increasing the density of accessible active sites is a general strategy in the development of solid catalysts. Delamination of layered double hydroxides (LDHs) offers an attractive route to obtain mixed metal oxides (MMOs) with enhanced morphological and basic properties via thermal decomposition. However, the role of post-delamination treatments, particularly the drying step, has received little attention. Here, we investigate the combined effects of aqueous-phase delamination and subsequent drying methods on the textural and surface characteristics of MMOs. Delamination introduces structural disorder and yields thinner, crumpled layers, as confirmed by cryogenic transmission electron microscopy and powder X-ray diffraction. Freeze-drying (FD) is essential for preserving the disordered structure, whereas oven-drying leads to reassembly into ordered layers due to atmospheric CO₂ exposure. CO₂ chemisorption measurements show a 4.3-fold increase at 400°C for an MMO synthesized via sonication-assisted delamination followed by FD, relative to its nondelaminated counterpart. Temperature-programmed desorption combined with in situ fourier transform infrared spectroscopy confirms the generation of stronger surface basic sites that effectively retain CO₂ at elevated temperatures. These findings demonstrate that the stacking state of nanosheet aggregates during the LDH-to-MMO transformation governs not only textural properties but also the distribution and strength of surface basic sites, extending beyond textural improvements.

This study reports the hydrothermal synthesis of PdX/CDs nanocomposites with varying palladium contents, confirmed by inductively coupled plasma mass spectrometry (ICP–MS) analysis, and their comprehensive physicochemical and electrochemical characterization for ethanol oxidation reaction (EOR) in alkaline media. The carbon dots (CDs), synthesized from D-galactose and L-histidine, serve as a porous, conductive support that enhances Pd nanoparticle dispersion and electronic conductivity. Among the catalysts tested, the Pd2/CDs nanocomposite exhibited superior performance, delivering a high anodic peak current density of 26 mA cm⁻², a low charge transfer resistance of 450 Ω, and a small Tafel slope of 61.97 mV dec⁻¹. Electrochemical stability was demonstrated through chronoamperometric tests, highlighting the catalyst's durability under alkaline conditions. Enhanced activity is attributed to the increased electrochemically active surface area, suppressed nanoparticle agglomeration, and efficient charge transport facilitated by the CDs. These findings position Pd2/CDs as a promising, cost-effective electrocatalyst alternative to platinum for direct ethanol fuel cells (DEFCs), addressing key challenges such as catalyst poisoning and slow kinetics while leveraging the advantageous structural and electronic properties of both Pd nanoparticles and carbon dots.

Developing efficient and durable nonprecious metal anode catalysts for visible-light-assisted methanol fuel cells remains challenging. This work innovatively constructs a Ni nanoparticle-decorated anatase TiO₂ heterojunction on Ti substrates (Ti/TiO₂-Ni) via a three-step anodization-calcination-electrodeposition strategy. The optimized Ti/TiO₂-Ni exhibits exceptional photo-electrocatalytic methanol oxidation performance, achieving a current density of 11.03 mA cm⁻² and a photocurrent density of 0.62 mA cm⁻² at 1.5 V (vs. NHE) under visible light. Crucially, it retains 85% activity after 12 h of continuous operation, demonstrating remarkable stability. Mechanistic studies reveal that the Ti/TiO₂-Ni heterojunction narrows the bandgap from 3.1 to 2.2 eV, extends visible-light absorption, and suppresses charge recombination. Furthermore, interfacial oxygen vacancies promote •OH generation, while photogenerated holes (h⁺) and •OH synergistically oxidize methanol and intermediates, mitigating surface passivation. This work provides a viable noble-metal-free heterojunction strategy for high-performance photo-assisted fuel cell catalysts.