Altogether, seven Zintl compounds in the solid solution Ca_9-xYb_xZn_4.5-yCu_ySb₉ (0 ≤ x ≤ 1.5, 0 ≤ y ≤ 0.15) system were successfully prepared by the molten Pb-flux and hot-pressing method. From the powder X-ray and single crystal X-ray diffraction investigations, all these isotypic phases were observed to have been crystallized in the Ca₉Mn₄Bi₉-type phase (space group Pbam, Z = 2, Pearson code oP45). The overall crystal structure consists of complex anionic [Zn₄Sb₉] clusters and the space-filling cationic elements. Notably, the central Zn1 site in a triangular coordinate exhibited a partial occupation and a relatively large atomic displacement parameter, which was necessary for the charge balance of the title compounds. All five intra-layer and inter-layer cationic sites showed the Ca/Yb mixed-occupancy with Yb presenting a specific site-preference for the A3 site. Density functional theory calculations unveiled a synergistic effect of the Yb-substitution and the p-type Cu-doping increased carrier concentration by reducing bond polarity through the tuning of the electronegativity difference. Thermoelectric property measurements further validated that the given synergistic effect was successful in enhancing the electrical conductivities of the quinary title compounds compared to the parental ternary compound Ca₉Zn_4.5Sb₉. As a result, the title compound Ca₈YbZn_4.4Cu_0.1Sb₉ achieved the largest figure-of-merit of 0.81 at 843 K, which should be attributed to improved electrical transport properties while maintaining balanced thermal conductivity.

As global energy demands escalate, hydrogen has gained increasing recognition as a viable alternative fuel and critical energy carrier for future industrial systems. This review examines unique safety challenges associated with industrial-scale hydrogen storage and transportation infrastructure within petroleum and chemical processing sectors. Systematic analysis of hydrogen storage and transportation equipment failure mechanisms reveals three primary risk dimensions: material degradation from hydrogen embrittlement, gas leakage in high-pressure configurations, and combustion/detonation hazards in complex industrial settings. A targeted accident prevention framework emerges through three synergistic strategies: (1) High-performance material engineering for pressure vessels and pipeline networks, (2) Smart monitoring architectures for leak detection in large-scale installations, and (3) Customized deflagration suppression systems for chemical plant applications. By synthesizing cutting-edge hydrogen safety technologies with industrial case analyses, the study proposes an integrated safety management paradigm combining material innovation, predictive monitoring, and explosion mitigation. These technical countermeasures address operational requirements of petrochemical enterprises in hydrogen infrastructure development while establishing comprehensive safety protocols for industrial hydrogen utilization. The insights offer implementable strategies for enabling secure, large-scale hydrogen deployment in energy-intensive petroleum refining and chemical production environments.

Lithium-sulfur (Li-S) batteries have emerged as a promising candidate for next-generation secondary batteries due to their high energy density and cost-effective sulfur cathodes. These batteries operate through electrochemical reactions involving sulfur, during which lithium polysulfides (LiPSs) are formed as liquid-phase intermediates. The solvation behavior of LiPSs plays a crucial role in determining the electrochemical performance and cycling stability of Li-S batteries. Electrolytes, as a key factor, govern the dissolution of LiPSs, with the properties, quantities, and ratios of components playing a critical role in forming the solvation structure of both Li⁺ ions and LiPSs. In this review, the extent of LiPS solvation is systematically categorized into highly, sparingly and weakly solvating electrolytes, and the influence of solubility on electrochemical performance is elucidated. Furthermore, the effects of additives and diluents on the solvation structures of LiPSs are analyzed to reveal the underlying mechanisms that govern their electrochemical behavior. This review emphasizes the importance of optimizing LiPS solvation properties through rational electrolyte design to enhance the performance and stability of Li-S batteries, providing valuable insights into the development of advanced electrolyte systems.

All-solid-state (ASS) lithium-sulfur batteries are promising power sources with the potential for high capacity and safety. Lithium metal polysulfide cathodes can address issues arising from the low electronic conductivity of Li₂S and S. This study synthesized lithium vanadium polysulfides (Li_xVS_y) by the mechanochemical treatment of Li₂S and V₂S₃. The Li_xVS_ysystem contains nanocomposites of Li₂S and LiVS₂ in an amorphous matrix; lithiation and delithiation occur in both Li₂S and LiVS₂ during charging and discharging. LiVS₂ enhances the electronic conductivity of Li_xVS_y (~10^-1-10^-2 S cm^-1) and the reversibility of charge-discharge reactions because of its high electronic conductivity and layered structure. Therefore, ASS batteries with Li_xVS_y show high capacity (~650 mAh g^-1), even without conductive additives. Here, ASS full cells with high loading assembled using a composite cathode comprising Li₈VS_5.5 and a solid electrolyte in a 80:20 (wt.%) ratio (33 mg cm^-2) and a composite Si anode (10.4 mg cm^-2) exhibited a high areal capacity of 15 mAh cm^-2, resulting in calculation of high energy densities of 853 Wh L^-1 and 515 Wh kg^-1 when assuming the cells were enlarged and stacked. This study is expected to expedite research on the development of high-performance ASS batteries.

Bi₂Te₃-based materials remain among the most promising thermoelectric candidates for applications in the temperature range of 300-400 K, owing to their high electrical conductivity, low thermal conductivity, chemical stability, and compatibility with scalable fabrication methods. However, conventional crystal growth techniques often lead to elemental segregation and compositional inhomogeneity. In this study, a rapid solidification approach using melt spinning was employed to mitigate segregation, yielding compositionally uniform Bi₂Te₃-based powders with particle sizes below 30 μm and nanometer-scale grain structures. The fabrication process - integrating planetary ball milling, annealing, melt spinning, and spark plasma sintering - significantly enhanced phonon scattering, thereby reducing thermal conductivity and improving overall material homogeneity. By systematically adjusting the tellurium content in Bi_0.5Sb_1.5Te_3-x, the composition with x = 0.15 was identified as optimal, achieving a peak dimensionless figure of merit (ZT) of 1.18 at 360 K.

A bidirectional co-doping of transition metal Fe and post-transition metal Sn on WO₃ photoanode via a facile one step flame-doping process demonstrates the challenging amelioration of both thermodynamic charge migration and surface catalytic kinetics, achieving high-efficient photoelectrochemical (PEC) water oxidation reaction in a neutral pH. The direct flamethrower with rapid thermal flux effectively induces the bidirectional doping of Fe³⁺ and Sn⁴⁺ into WO₃ without damaging its nanostructure and fluorine-doped tin oxide glass substrate. From the synergetic effect of the dual-metal doping, the photoinduced charge migration and the surface water oxidation kinetics are effectively ameliorated. As a result, the Fe/Sn co-doped WO₃ photoanode shows significantly enhanced PEC response with 6.16-fold higher photocurrent density performance at 1.23 V_RHE than bare WO₃. This work highlights the facile metal atom co-doping method without affecting intrinsic properties of photoanode and substrate for boosting the PEC water splitting performance and solar fuel production.

Improving the anomalous Nernst coefficient (S_ANE) in permanent magnets is essential for increasing the power density in transverse thermoelectric generators, which use permanent magnets to operate the anomalous Nernst effect without relying on an external magnetic field. While recent studies indicate that microstructural engineering can affect S_ANE, the specific relationship between microstructure and S_ANE in permanent magnets remains underexplored. This study investigates S_ANE of hot-pressed, hot-deformed, and RE-Cu (RE = Dy-Nd, Nd, and Pr) grain boundary diffusion-processed Nd-Fe-B magnets. The results show that S_ANE increases by 68%, from -2.6 × 10^-7 VK^-1 in the hot-pressed state to -4.4 × 10^-7 VK^-1 after hot-deformation in which grain growth and crystallographic texture are realized without changing the composition of the magnets. S_ANE further increases to -5.0 × 10^-7 VK^-1 after grain boundary structure and composition change from thin amorphous phase to thick crystalline phase by grain boundary diffusion of Dy-Nd-Cu alloy. The increase in S_ANE is found to be primarily due to the reduction of the opposing transverse electric field caused by the Seebeck-effect-induced carrier flow bent by the anomalous Hall effect. Owing to the crystallographic texture formation after hot-deformation, almost the same transverse thermopower as S_ANE is obtained in the hot-deformed and RE-Cu grain boundary diffusion-processed Nd-Fe-B magnets at a remanence state, i.e., under zero magnetic field. These findings demonstrate that microstructural optimization can effectively enhance the S_ANE in ultra-fine grained Nd-Fe-B magnets, providing a promising avenue for advancing materials in applications of transverse thermoelectrics.

Global electrification has been realized through lithium-ion battery system by extending its application into large-scale devices and energy storage systems. Besides, economic regulations, such as those related to climate change and carbon neutralization, have accelerated the dissemination of battery chemistry for substitution of fossil fuels. As the battery application is widely expanded into large-scale system, additional requirements such as high-energy-density and long-term cycle stability have emerged, leading to the exploration of advanced battery materials and systems beyond conventional configuration. Thus, high-Ni cathode has attracted attention owing to higher specific capacity and unexpected issues arising from structural imperfection have been recently addressed through structural carving of materials. However, to deeply investigate battery systems using high-Ni cathodes, the perspective should be extended beyond the material to the electrode level. In this paper, emerging issues and systematic strategies for the advanced high-Ni cathode at the electrode level are reviewed to provide insight into compatible electrode/material design and highlight practical development toward high-energy-density batteries.

Chemical and fuel production through conventional catalytic processes requires significant improvement to reduce CO₂ emission levels. Sustainable, potentially direct, chemical production is in critical need, such as methane coupling to olefins, propane dehydrogenation to propylene, biodiesel production, and greenhouse gas emissions modulating reactions, including CO₂-utilizing dry reforming of methane, partial oxidative of methane, CO oxidation, CO₂ methanation are some of the emerging technologies to address sustainability challenges. These technologies remained constrained due to the lack of stable and efficient catalysts. Hydroxyapatite (HAP), a highly functional versatile material, offers great potential due to its flexible tunability, and several studies have outlined the synthesis protocol of HAP and design modifications for catalytic applications. However, a comprehensive understanding of connecting reaction-specific demands to tailor HAP catalyst designs is limited. In this review, we bridge that gap, highlight key challenges in catalytic reactions, and propose the necessary HAP catalyst modifications, including acid-base tuning, defects-induced lattice oxygen or vacancies, mesoporosity modulation, and catalyst active metal species dispersion, to improve catalytic performance by limiting catalyst deactivation from absorbates surface poisoning, sintering, and coking. Finally, future research areas for improvement for HAP catalysts are suggested to advance the maturity of catalytic technologies.

The imminent global energy crisis and the growing global demand for electricity, which require the development of alternative energy conversion technologies such as organic thermoelectrics, have attracted much attention from the scientific community due to their capability to convert low-grade waste heat into electrical energy. In the last decades, p-type and n-type thermoelectric polymers have been studied extensively and have achieved significant progress in thermoelectrics. In particular, diketopyrrolopyrrole (DPP)-based thermoelectric materials have gained much attention from researchers due to their unique structural properties. This review discusses potential of DPP-based thermoelectric materials and explores recent progress on DPP-based p-type and n-type (which are relatively underexplored) thermoelectric polymers in detail, which involved the structure-property relationship, doping strategies, morphology control, and the impact of molecular design, including noncovalent interactions, backbone engineering, and dopant-polymer compatibility on thermoelectric performance of DPP-based materials and new strategies that will empower the rational design of next-generation polymeric materials for thermoelectric applications.

Owing to the sluggish kinetics of oxygen evolution reaction (OER) in electrochemical water electrolysis process, efficient and durable OER electrocatalysts are crucially needed. However, it is a great challenge to improve the comprehensive performance of OER electrocatalysts by utilizing various synergistic methodologies. To solve these issues, herein, Ir-doped Co-based compounds with regulated anions were synthesized using a coprecipitation method as the electrodes for boosting the OERs. Doping with Ir atoms modified the coordination environments and electronic structures of the CoO_x-CO₃^2- lattice, and the generated Co³⁺ species promoted the generation of active species for the OER. It is worthwhile noting that a hybrid crystalline/amorphous IrCoO_x-CO₃^2- compound was obtained with an Ir content of 10.09 wt.% and a large amount of Co³⁺, and demonstrated excellent electrocatalytic OER performance. The overpotential required for the developed IrCoO_x-CO₃^2- to achieve 10 mA cm^-2 was as low as 207 mV with a very low Tafel slope of 61.7 mV dec^-1, which is better than the commercial IrO₂. Furthermore, anions created in the IrCoO_x significantly promoted the OER, and their effects were decreased in the order of CO₃^2- > PO₄^3- > OH^-. This work clarifies the synergistic mechanism of cations and anions on the electrocatalytic OER performance of Co-based compounds, providing new insights for designs of high-performance OER electrocatalysts for water electrolysis.

Mg₂(Si,Sn)-based semiconductors constitute promising thermoelectrics (TE), in particular as n-type materials. These are usually synthesized under Mg-excess to compensate for losses of Mg during synthesis and achieve the high carrier concentration required for optimal performance. However, this usage of excess Mg leads to loosely bound Mg in the material which is easily lost during operation, leading to a fast and massive degradation of the TE performance. In this work, we introduce Mg-poor n-type Mg₂(Si,Sn), avoiding excess and loosely bound Mg. We find that (i) employing relatively large nominal Mg deficiency leads nevertheless to single-phase, Mg-poor Mg₂(Si,Sn) by a self-adjustment of the composition during sintering, and (ii) that despite showing a lower dopant efficiency, Sb can be employed to achieve the required optimum carrier concentration, resulting in a figure of merit of zT = 1.2 ± 0.2 at 700 K, comparable to Mg-rich samples. This is confirmed by a comparison of Mg-rich and Mg-poor samples in a single parabolic band model which reveals similar microscopic material parameters such as weighted mobility and scattering constants. Finally, we compare Mg-poor synthesized samples with initially Mg-rich ones that experienced Mg loss. Despite similar global compositions we identify grain boundary scattering to be more pronounced in Mg-depleted samples, marking one of the fundamental reasons for the performance degradation of synthesized Mg-rich synthesized samples. Overall, this work highlights the importance of grain boundaries for the performance of TE materials and the successful application of thermodynamic degrees of freedom to address fundamental challenges in TE material systems while retaining promising TE performance.

Photoelectrochemical water splitting is a promising alternative for sustainable energy production, addressing the growing need for clean energy sources. Hematite is a potential semiconductor for this process due to its abundance, low cost, non-toxicity, and stability. However, bare-hematite-based photoelectrochemical cells face challenges such as low photocurrent density, requiring innovative strategies to improve efficiency. This study explores the combined effects of three key approaches: enhancing crystallinity through high-temperature annealing, increasing specific surface area via nanostructuring, and improving photoanode conductivity through heteroatom doping. Hematite nanowires were synthesized using a hydrothermal method, with Ti-doping introduced during hydrothermal synthesis and subsequent Sn co-doping during an 800 °C annealing process, which also improved crystallinity. The introduction of Ti dopant significantly increased the photocurrent density under simulated solar illumination from 0.03 mA·cm^-2 to 0.63 mA·cm^-2. Co-doping with Ti and Sn further enhanced performance to 1.27 mA·cm^-2. The research explores how heteroatom doping influences the properties of hematite and examines its interaction with high-temperature annealing. These findings are significant for advancing the design of efficient nanostructures for energy conversion applications.

Silicon is a promising anode material for next-generation lithium-ion batteries (LIBs) due to its high theoretical capacity. However, its practical use is hindered by significant volume expansion during charge cycles, which causes poor cycling stability. Intense pulsed light technology offers a solution through rapid, selective heating, enabling nanoscale transformations without damaging substrates. Here, a scalable approach for creating silicon patterns on polymer foils and converting them into nanoscale composite layers under ambient conditions is presented. The use of inkjet printing in conjunction with intense Pulsed Light treatment is demonstrated to generate localized temperatures in excess of 1,940 °C within milliseconds, whilst maintaining the integrity of the polymer substrate. This rapid heating method induces local carbonization of the polymer, thereby converting the Si nanoparticles into a new silicon carbide (SiC) embedded in a few-layer graphene composite electrode. The resulting heterostructure anode exhibits excellent electrochemical performance, improved cycling stability, and enhanced rate capability, positioning it as a promising binder-free silicon anode for next-generation lithium-ion batteries.