Hydrogen energy as a renewable resource has drawn wide attention. However, the lack of efficient and durable catalysts for ammonia borane (AB) dehydrogenation hinders its practical application. In this work, CoCuP nanoparticles were anchored on Ti3C2 MXene nanosheets through a molten-salt-assisted strategy and subsequent phosphidation. The optimized CoP2-Cu3P/Ti3C2 catalyst integrates Co-Cu bimetallic synergy, phosphorus–induced electronic modulation, and metal-support interactions, thereby enabling efficient interfacial charge transfer and abundant accessible active sites. As a result, CoP2-Cu3P/Ti3C2 delivers rapid hydrogen generation from ammonia borane hydrolysis under visible light, with complete H2 release within 0.68 min at 298 K, a turnover frequency of 1168.8 h−1, and an apparent activation energy of 42.46 kJ mol−1. These findings highlight CoCuP/Ti3C2 interface engineering as a viable strategy for constructing low-cost and high-performance catalysts for chemical hydrogen storage.

The strategy for catalyzing ammonia borane (NH3BH3) hydrolysis represents a potential hydrogen production technology, yet its practical application is restricted primarily due to the high-cost of catalysts. In this study, supported Co-Sr-B thin film catalysts have been constructed on Ni foam substrate via chemical deposition route and adopted for catalyzing NH3BH3 hydrolysis. By adjusting the depositional pH value to 12 and fixing the molar ratio of Co2+ and Sr2+ to 3:7, the Co-Sr-B thin film catalyst exhibits an enhanced catalytic performance. On this basis, the optimized Co-Sr-B/TiO2 thin film catalyst is prepared on Ni foam by controlling the amount of TiO2 at 0.1 g, delivering an outstanding H2 generation rate of 5794 ml·min−1·g−1 at 298 K and lower activation energy value of 25.8 kJ·mol−1 under light condition. In addition, the fabricated Co-Sr-B/TiO2 thin film catalyst maintained satisfactory cyclic stability. Comparative results demonstrate that the catalytic performance Co-Sr-B/TiO2 thin film catalyst has obviously outstripped Co-B and Co-Sr-B thin film catalysts deposited at the identical conditions, and even most reported catalysts. Combined with microstructural characterizations, spectral analysis and electrochemical measurement, it is revealed that Co-Sr-B/TiO2 thin film catalyst shows the high surface roughness, efficiently suppresses the recombination rate of the photogenerated electron-hole pairs, and enhances the separation and mobility of photogenerated charges. These factors synergistically contribute to the remarkable improvement of its catalytic activity toward NH3BH3hydrolysis, which illustrates that the utilization of TiO2 and Ni foam to prepare supported Co-Sr-B thin film catalyst represents an effective strategy.

This review summarizes the catalytic mechanisms, confined synthesis strategies, and structure–activity relationships of HDSACs in key electrochemical energy conversion reactions, aiming to guide the rational design of high-performance HDSACs.

In this work, the optimal Co-Ce-B/g-C3N4 thin-film catalyst was prepared on high-purity Ti foil by chemical deposition after optimizing pH value. It manifested an outstanding hydrogen generation rate of 6330ml·min-1·g-1 at 298K, together with a notably low apparent activation energy of 33.9kJ·mol-1 toward NaBH4 hydrolysis under light irradiation. The results substantiated that the ternary Co-Ce-B/g-C3N4 delivered superior catalytic activity relative to the binary Co-B/g-C3N4 and many of the reported catalysts. It might be attributed to the its distinctive microstructural features and synergistic interaction of multi-component system. Characterization analysis confirmed that the recombination of photoinduced electron–hole pairs was effectively suppressed within the ternary catalyst, meaning accelerated separation and interfacial transfer of photogenerated charge carriers, and leading to a pronounced improvement of catalytic efficiency for hydrogen generation from NaBH4 hydrolysis. In addition, after 5 cycles, the catalytic activity of Co-Ce-B/g-C3N4 remained 63.7% of its initial value, revealing moderate cycling stability that requires further enhancement for practical implementation.

Isopropanol (IPA), a volatile organic compound linked to diabetic ketosis (DK), has emerged as a critical biomarker for early diabetes detection and management. Developing portable, room-temperature sensors for exhaled IPA analysis could enable non-invasive, point-of-care diagnostics. Here, we present a compact, surface plasmon resonance (SPR) fiber-optic sensor functionalized with Pt-doped ZnO nanoparticles for ultrasensitive IPA detection at room temperature. This material design amplifies the sensing performance through a synergetic effect of the catalysis of oxygen chemisorption on the ZnO and electronic sensitization by the Pt/ZnO Schottky junction. Systematic evaluation demonstrates that operating stably at 26 °C, the sensor exhibits a remarkable sensitivity of -0.405 a.u./ppm, a detection limit of 7.407 ppm, and high interference resistance. This successful integration of nanomaterial-enhanced sensitivity with a portable fiber-optic platform offers a transformative route for developing accessible tools for early diabetes detection and personalized metabolic monitoring.

Since nitrogen dioxide (NO2) is an air pollutant that can seriously harm human health, developing high-performance gas sensors capable of efficiently detecting nitrogen dioxide at room temperature is of great significance for environmental monitoring and health protection. In this work, we synthesized hierarchical spherical MoS2 with a high specific surface area via a hydrothermal method and uniformly loaded Pd nanoparticles onto its surface through an in-situ reduction strategy, successfully constructing a Pd/MoS2 composite material. Characterization techniques including SEM, TEM，XPS confirmed the successful loading of Pd nanoparticles and the electronic interaction between Pd and MoS2. Experimental results demonstrate that the 1% Pd/MoS2 composite exhibits optimal sensing performance toward NO2 at room temperature: a high response value (Rg/Ra) of 9.33 toward 10 ppm NO2, along with excellent selectivity, repeatability, and long-term stability. Density Functional Theory (DFT) calculations further elucidated the enhancement mechanism: the introduction of Pd significantly increased the adsorption energy of NO2 on the material surface (from -0.253eV to -1.41eV), thereby greatly improving the sensor's sensitivity and response kinetics. This research provides an effective material design strategy and theoretical foundation for developing high-performance, low-power-consumption room-temperature NO2 gas sensors.

The advancement of titanium-based solid-state hydrogen storage technologies and titanium manufacturing processes inherently involves the formation of hydrogen/titanium dust hybrid mixtures, which present substantial explosion hazards. To investigate the explosion behavior of such two-phase systems, this study systematically examined the variation patterns of explosion intensity parameters in hydrogen/titanium dust hybrid systems using a standardized 20 L spherical explosion vessel. The experimental matrix covers hydrogen volume fraction ranging from 0% to 30% and titanium dust mass concentrations from 100 to 700 g/m3. Specifically, titanium dust concentrations were tested at seven discrete levels (100, 200, 300, 400, 500, 600, and 700 g/m3), while hydrogen volume fractions were selected at eight critical values (4%, 5%, 10%, 15%, 20%, 25%, 29%, and 30%). Dynamic parameters, including explosion pressure and rate of explosion pressure rise, were synchronously recorded. Furthermore, the phase composition and surface chemical states of explosion residues were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). This integrated approach provides in-depth insights into the macroscopic evolution of explosion intensity with varying gas-solid ratios and elucidates the underlying microscopic reaction mechanisms. Experimental results demonstrate that hydrogen volume fraction critically modulates explosion severity. The explosion pressure exhibits a characteristic three-stage dependence on hydrogen volume fraction: it initially decreases, reaching a minimum at 4% H2, subsequently increases to a maximum at 29% H2, and finally declines at higher volume fractions. Correspondingly, the maximum rate of pressure rise rate decreases to its lowest value at 4% H2 before increasing continuously up to 30% H2. The maximum explosion pressure shows an analogous trend, peaking at 29% H2 after an initial reduction, while the maximum rate of pressure rise reaches its minimum at 4% H2 and peaks at 30% H2. Residue analysis indicates that at low hydrogen volume fraction (<4%), incomplete oxidation of titanium predominates, thereby reducing explosion intensity. Beyond the critical threshold of 4% H2, hydrogen self-combustion promotes titanium-nitrogen reactions and facilitates the transition from heterogeneous to homogeneous combustion, significantly enhancing explosion severity. This investigation provides fundamental insights into the explosion dynamics of hydrogen/titanium dust mixtures and delivers essential parameters for risk assessment and safety mitigation in related industrial applications.

The hydrolysis of sodium borohydride (NaBH4) can release high-pure hydrogen (H2) in the presence of a suitable catalyst. In this work, Co-Ce-B/Ti foil catalysts were fabricated by electroless plating method. After optimizing the depositional time and pH value, the influence of nCe:Co on the structure and catalytic activity was investigated for the NaBH4 hydrolysis catalyzed by Co-Ce-B/Ti foil. When the nCe:Co value was 3:7, Co-Ce-B/Ti foil demonstrated the hydrangea-like nanostructures with small particle diameters and high surface roughness. It helped to adsorb NaBH4 and H2O on the catalyst surface, stabilize the intermediate and then reduce the reaction barrier. The H2 generation rate of catalyzing NaBH4 hydrolysis was 5774 mL center dot min- 1 center dot g- 1 at 298 K and 15503 mL center dot min- 1 center dot g- 1 at 313 K, and the apparent activation energy was 48.5kJ center dot mol- 1 under the action of Co-Ce-B/Ti foil (nCe:Co = 3:7). This performance was superior to that of many previous reported catalysts, which could be attributed to the distinctive microstructure, high surface roughness and the synergistic action of the multiple elements. Moreover, the catalyst still maintained relatively high activity after 5 cycles, and the partial attenuation could be due to the structure collapse and cracks, and the continuous accumulation of the by-product NaBO2 on catalyst surface.

Mechanical damage caused by compressive deformation represents a typical form of mechanical abuse in lithium-ion batteries. In this study, 18650-type NCM lithium-ion batteries were subjected to mechanical deformation at two levels (11% and 22%). The evolution of temperature, capacity, and internal resistance under mechanical abuse was investigated during 1C, 2C, and 3C charge-discharge cycles (1C rate = nominal capacity per hour). The thermal runaway behavior of the cells was further examined under overcharging and overheating conditions. The results reveal that with increasing damage severity, both the DC internal resistance and charging temperature increase correspondingly. NCM lithium-ion batteries subjected to critical compression exhibit a distinct bimodal temperature profile during high-rate charging. Moreover, mechanically damaged cells display artificially elevated capacity readings and accelerated performance degradation after repeated high-rate cycling. Specifically, batteries with approximately 22% compression show inflated capacity and prolonged charging durations at 2C and 3C rates, indicating irreversible internal damage. Under 3C high-rate overcharging, undamaged cells did not undergo significant thermal runaway, whereas their damaged counterparts experienced premature failure. Under thermal runaway conditions, critically compressed batteries exhibited faster onset of thermal runaway and higher peak temperatures. These findings demonstrate that partially damaged NCM lithium-ion batteries can still operate normally, but they present a substantially higher risk of thermal runaway compared to undamaged cells.

Trace formaldehyde (HCHO) breath analysis requires sensors with ultra-low detection limits and high humidity tolerance. Achieving thermodynamically stabilized Ce3+ in conventional oxides remains challenging due to the strong dependence of Ce valence on synthesis conditions. Herein, we show that the multication lattice of CuBi2O4 enables site-dependent Ce valence regulation: Ce prefers +3 at Bi sites and +4 at Cu sites (DFT/XPS: 51% Ce3+ in CBO:Ce 0.25%). 1H SSNMR reveals that Ce doping disrupts the surface hydrogen-bonded network responsible for humidity-induced degradation. Consequently, CBO:Ce 0.25% achieves a response retention of 49.32% from 10% to 90% RH (vs. 11.13% for pristine CBO) while preserving a high response (3.91 at 90% RH toward 50 ppb HCHO) via active hydroxyl scavenging through the Ce3+/Ce4+ redox cycle—in contrast to the physical blocking approach of FAS modification, which attains higher retention but severely compromises sensitivity. This work establishes site-specific Ce3+ stabilization as a design strategy for humidity-tolerant MOS sensors.

Developing an ozone (O3) sensor with high sensitivity and low detection limits under variable humidity conditions remains a longstanding challenge. Here, we report an oxygen-vacancy-rich In2O3 (Va-In2O3) sensor fabricated via vacuum annealing combined with a temperature-modulation strategy. These oxygen vacancies not only provide a large number of active sites for O3 adsorption but also decrease the band gap and increase the carrier concentration, thereby enhancing the electron mobility. As a result, the Va-In2O3 sensor can detect O3 at a lower limit of 10 ppb under 3% RH, and its response is 12.6 times that of In2O3. Meanwhile, it still maintains high sensitivity even at 73% RH, and the response to 30 ppb O3 is 63.7. Furthermore, the temperature modulation strategy enables decoupling of the sensing and recovery processes, achieving high response at low temperature and rapid recovery at elevated temperature. Additionally, the temperature modulation strategy optimally matches the response process with the recovery process, achieving rapid recovery (<5 s) under high response conditions. This work provides an effective oxygen vacancy regulation strategy for achieving high-performance O3 detection under actual conditions.

Machinability of Ti2AlNb alloy fabricated by additive manufacturing is investigated via temperature-controlled ultrasonic vibration assisted milling experiments. This study explores the mechanisms of surface defect suppression, material removal behavior, and near-surface grain refinement during the process. Results indicate that the tool path formed by ultrasonic vibration can promote the lifting and detachment of hard particles within workpiece microstructure, avoiding scratches on the workpiece surface and significantly improving surface quality. With the O phase and grain boundary α2 phase precipitated by heating, micro-voids are generated between the thermally precipitated O phase and B2 phase matrix, while microcracks form inside the α2 phase under ultrasonic vibration. As the micro-voids and microcracks propagate, a weakened zone is progressively developed within the cutting zone, leading to an 85% reduction in cutting force under optimal parameters. Based on the one-dimensional fluctuation equation, ultrasonic vibration enhances energy input during machining, promoting the healing of near-surface pores and the formation of a pore-free layer with a specific thickness. The thickness of the pore-free layer increases with escalation of ultrasonic vibration energy input, a phenomenon that is crucial for improving the material properties. Under the synergistic effect of thermal softening and ultrasonic vibration energy impact, the high-density dislocations in the microstructure of additive manufacturing material continuously accumulate, annihilate, and rearrange, ultimately achieving grain refinement. Experimental data demonstrate that, in comparison with conventional machining, the grain size of the near-surface layer is reduced by 56.1% when the amplitude is set to 3 μm.

In this study, three-dimensional hierarchical SnS2 nanoflowers assembled from nanosheets with an average thickness of 13 nm were synthesized via a facile hydrothermal method. Ag nanoparticles were then modified on the surface of SnS2 by an in-situ chemical reduction method to form Ag/SnS2 nanocomposites. The introduction of Ag nanocrystals could enhance the response and stability toward NO2 gas and decrease the optimal operating temperature from 100 degrees C to 80 degrees C. And the Ag/SnS2-based sensor with an Ag content of 1.0 at% (1.0-Ag/SnS2) exhibited the maximum sensitivity and excellent selectively. The response value (60) of the 1.0-Ag/SnS2 sensor to 8 ppm NO2 at 80 degrees C was 3.75 times higher than that (16) of the pristine SnS2 sensor at 100 degrees C. The improved sensing properties could be attributed to the spillover effect of Ag nanocrystals and the formation of Schottky junction between Ag and SnS2. Furthermore, the adsorption energies of Ag-modified SnS2 for NO2 molecules were calculated using first-principles calculations. The results suggested a strong adsorption capacity and interaction between NO2 and Ag/SnS2, which was beneficial for enhancing the gas-sensing performances.

In this study, Mo,W:BiVO4 was used as the photoanode substrate, and a Mo,W:BiVO4/CeFeO3-P composite photoanode was fabricated via a dual modification strategy combining CeFeO3 heterojunction construction with surface phosphorization. This constitutes the first reported n-n heterojunction between Mo,W:BiVO4 and CeFeO3. The well-matched band structures of the two semiconductors lay a solid foundation for subsequent phosphorization and outstanding photoelectrochemical performance. Structural characterization reveals that sheet-like CeFeO3 is in intimate contact with Mo,W:BiVO4 to form an n-n heterojunction, and amorphous surface P modification optimizes the surface electronic structure and coordination environment. The dual modification synergistically suppresses photogenerated carrier recombination, reduces interfacial charge transfer resistance, and enhances hole injection efficiency and surface catalytic kinetics. Under AM 1.5 G simulated sunlight, the optimized photoanode achieves a photocurrent density of 5.64 mA·cm−2 at 1.23 V vs. RHE by LSV at 50 mV·s−1, significantly higher than those of pristine Mo,W:BiVO4 and singly modified samples. Under potentiostatic conditions at the same potential, it delivers a stable photocurrent density of approximately 4.0 mA·cm−2, retaining 84.2% of its maximum value after 6 h of continuous operation. This work verifies the feasibility of the heterojunction and surface phosphorization synergistic strategy and clarifies interfacial electronic interactions and charge transfer mechanisms.

The growing concerns over environmental NO2 pollution have sparked considerable interest in developing highperformance metal oxide semiconductor (MOS) sensors featuring high sensitivity and satisfactory selectivity. In this work, a Ce-doping strategy was proposed to boost the NO2 sensing properties of MoO3. Ce-doped MoO3 nanobelts with varying Ce contents (0, 1, 2, and 3 mol%) were synthesized via a facile hydrothermal approach. Structural and compositional characterizations verified the substitution of Mo6+ by Ce3 + ions in the MoO3 lattice, resulting in an increased Mo5+/Mo6+ ratio and elevated oxygen vacancy concentration, while the morphology and specific surface were largely preserved. Gas-sensing measurements indicated that the optimal Ce-doped MoO3 (CM2) exhibited a response (Rg/Ra) of 5.22 for 4 ppm NO2 at 190 degrees C, approximately 2.56 times higher than that of pure MoO3. Moreover, the selectivity coefficients of CM2 for NO2 over various interfering gases were more than twice those of bare MoO3. This study provides a promising Ce-doping strategy for developing highperformance MoO3-based NO2 sensors.

NO2 as a toxic atmospheric pollutant, causes irreversible damage to human health, necessitating the development of highly sensitive, selective, and low-power NO2 sensors for environmental and healthcare monitoring. In this work, we report a bimetallic co-doping strategy by incorporating an appropriate amount of gallium (Ga) and tungsten (W) ion into the SnS2 lattice, successfully synthesizing Ga/W co-doped SnS2 microspheres. The optimized sensor demonstrated exceptional NO2 sensing characteristics, exhibiting a response value of 10.41 toward 5 ppm NO2 at 100 degrees C, along with a ppb-level detection limit. The enhanced sensing performance can be primarily attributed to the synergistic effect of sulfur vacancies and increased specific surface area induced by co-doping of Ga and W, which collectively improve gas adsorption and provide more active sites for gas-sensing reactions. Atomic-scale calculations based on density-functional theory (DFT) elucidates the microscopic mechanism of the enhanced gas-sensing performance of the system at the electronic structure level. It reveals that the adsorption energy of NO2 is significantly enhanced, and the N-O bond undergoes significant bond length relaxation, while the interfacial charge transfer increases dramatically by the Ga/W co-doping into SnS2. This multifactorial synergistic effect provides an atomic-level theoretical basis for the design of high-performance NO2 sensors.

Surface-enhanced Raman scattering (SERS) enables label-free detection with molecular fingerprinting, but its application is often limited by complex fabrication processes and nonuniform signal distributions. To address these issues, we developed a three-dimensional superhydrophobic substrate consisting of porous pyramidal Si decorated with silver nanoparticles (PP-Si@AgNPs). Compared with the conventional Si@AgNPs and Py-Si@AgNPs, the hierarchical structure enhances light absorption to 78% at 532 nm and increases the specific surface area exposed under the laser spot. The superhydrophobic surface (152.6°) reduces the droplet contact area by 88.6%, increasing the surface density of analyte molecules by 8.8-fold and enhancing the SERS intensity by 7.85-fold. Using rhodamine 6G as a probe molecule, the substrate presents a detection limit of 10−13 M and an enhancement factor of 5.85 × 109. The relative standard deviations of 3.34% and 6.39% indicate excellent spot-to-spot and batch-to-batch reproducibility. Moreover, the substrate enables low-concentration detection of malachite green in fish skin extract (7.8 × 10−11 M), thiram in apple extract (1.6 × 10−8 M), and melamine in milk (1.0 × 10−8 M), highlighting strong potential for practical analytical applications.

Real-time and highly selective monitoring of acetone (C3H6O) is crucial for industrial safety and occupational health. Herein, we report a Ce-doped BiFeO3 (BFO) sensing material synthesized via a sol-gel method, which enables simultaneous regulation of grain size, polarization strength, crystal phase composition, band structure, and defect. The optimized sensor (denoted as BC2FO, 2 mol% Ce-doped) exhibits excellent C3H6O sensing performance over a concentration range of 0.2-10 ppm at 220 °C, and its response value to 2 ppm C3H6O is twice that of the pure BFO sensor. Ex situ XPS and in situ Raman further revealed the sensitive reaction mechanism between C3H6O gas molecules and the BC2FO composite material. Furthermore, the machine learning classification algorithm was introduced for highly accurate identification of C3H6O against isopropanol (C3H8O). An intelligent warning system based on BC2FO micro-electro-mechanical system (MEMS) sensors has been developed, which successfully achieved continuous monitoring and automatic on-site alarm in simulated industrial leakage scenarios. This study presents a comprehensive and robust paradigm combining material engineering, machine learning-assisted recognition, and hardware integration for the detection of C3H6O.

Developing hydrogen (H2) sensors that combine high sensitivity with rapid response/recovery kinetics presents a notable challenge in ensuring the safe use of this clean energy carrier. To address this, Pd/PdO nanoparticles were decorated onto NiO/Al2O3 composites derived from NiAl layered double hydroxides (LDHs) via hydro-thermal synthesis followed by calcination. Characterization revealed that the optimal 2.0 wt% Pd/PdO-NiO/ Al2O3 sample showcases a high concentration of oxygen vacancies, a large specific surface area (149.73 m2/g), and abundant porosity. Gas sensing evaluation demonstrated that this material exhibits a significantly enhanced response (2.921) to 100 ppm H2 at an operating temperature of 350 degrees C. Crucially, it achieves remarkably fast response and recovery times of 14 and 19 s, respectively. Furthermore, the sensor demonstrates excellent selectivity and long-term stability. This work presents a promising strategy based on Schottky junction engineering within LDH-derived composites for realizing ultrafast and sensitive H2 detection.

Herein, we propose a ZnO and Pt co-modification strategy to boost the NO2 sensing performance of SnO2. Specifically, a ternary Pt/ZnO/SnO2 composite was prepared by sequentially decorating ZnO and Pt nanoparticles onto a porous nanorod-assembled hierarchical structure (PNRHS) of SnO2. The resulting Pt/ZnO/SnO2 composites were characterized using various techniques, and their sensing properties to NO2 were investigated. The results reveal that after co-modification with ZnO and Pt, the SnO2 sensor exhibits remarkable performance enhancements in detecting sub-ppm-level NO2, including significantly improved sensitivity, superior gas discrimination capability, and accelerated response kinetics. At its optimal working temperature of 140 degrees C, the optimized Pt/ZnO/SnO2 sensor demonstrates a response of 105.6-1 ppm NO2, approximately 42.2, 7.4, and 7.9 times than that of the pure SnO2 (2.5 at 120 degrees C), ZnO/SnO2 (14.3 at 150 degrees C), and Pt/SnO2 (13.3 at 140 degrees C) sensors, respectively. The enhanced NO2 sensitivity of the ternary Pt/ZnO/SnO2 composite sensor is attributed to the synergistic sensitization effects of the ZnO and Pt modifiers, whose underlying mechanisms are discussed.