ABSTRACT The electrochemical reduction of carbon dioxide (CO 2 RR) to usable fuels and chemicals is one of the most prospective green and sustainable strategies to achieve worldwide carbon management. However, finding efficient and cost‐effective electrocatalysts that can achieve high energy and Faradaic efficiencies, as well as facilitating fast and selective conversion, remains a significant challenge. Porous carbon doped with earth‐abundant metals and non‐metals are highly promising cathodes for CO 2 RR due to their low cost, outstanding surface area, high electrical conductivity, and accessible active sites, in addition to ease of high‐mass production from earth‐abundant resources. Consequently, a wide range of strategies have been developed for the rational synthesis of porous doped carbon materials with diverse morphologies and compositions for CO 2 electroreduction into gaseous and liquid products. Given the rapid advancements and growing interest in this field, timely updates are essential to guiding future research and development. This review provides a comprehensive overview of porous carbon nanostructures functionalized with transition metals and p‐block metals (e.g., Ni, Fe, Cu, Mn, Co, Zn, In, Bi, Sn) as well as non‐metal dopants (e.g., S, F, B, P), including their hybrid configurations. We highlight how the spatial arrangement and electronic interactions of metal/non‐metal species influence CO 2 RR performance, and we discuss fundamental aspects such as reaction mechanisms, active site modulation, and reactor designs. Special attention is given to dual‐site and multi‐metallic systems, which often exhibit synergistic effects beyond those of their single‐metal counterparts. The review concludes with a critical outlook on the challenges and opportunities in designing next‐generation CO 2 RR electrocatalysts through precise control over porous carbon–metal interfaces.
ABSTRACT Sodium‐ion batteries (SIBs) have garnered significant attention as promising alternatives for large‐scale energy storage devices, owing to abundant sodium resources and the similar chemical properties with lithium. However, the inability of graphite for Na storage presents a substantial barrier to commercial application of SIBs. While hard carbons (HCs) offer potential pathways for commercial SIBs, challenges such as low initial Coulombic efficiency, limited Na storage capacity, unclear structural understandings, and contentious energy storage mechanisms remain prominent issues. Driven by keen interests in elucidating the structure and Na storage mechanisms, numerous characterization techniques have been employed to monitor the structure information and structural evolution in sodiation‐desodiation process. Consequently, it is imperative to introduce these characterization techniques and their integrations followed with recent updates in a timely manner. This review provides a concise overview of HCs alongside their related Na storage mechanisms, addressing the development process, existing issues, and future perspectives. Furthermore, we comprehensively categorize and update various characterization techniques for HCs, while representative studies are selected to facilitate a deeper understanding of results and analyses. Finally, we clarify future directions for characterization techniques, highlighting potential avenues for further development that could significantly influence the design and fabrication of high‐performance HCs for SIBs.
ABSTRACT The gravimetric and volumetric energy densities of 500 Wh kg –1 and 1000 Wh L –1 are considered as the “holy grail” target values for the development of all‐solid‐state lithium pouch batteries. However, the substantial amount of non‐energy‐providing deformable catholytes in conventional catholyte‐based composite cathodes limits the theoretical values of the energy densities to approximately 400 Wh kg –1 and 900 Wh L –1 , respectively. Here, we propose a design strategy for catholyte‐free composite cathodes using deformable halide cathode for the replacement of the non‐energy‐providing catholyte to increase the energy density. Based on this strategy, the gravimetric and volumetric energy densities of all‐solid‐state lithium pouch batteries improve by an average of 30% and 11%, respectively. Compared with conventional catholyte‐based composite cathodes, the energy densities of these batteries now exceed 500 Wh kg –1 and 1000 Wh L –1 , respectively. The catholyte‐free composite cathode design is expected to facilitate the industrialization of high‐energy‐density all‐solid‐state lithium pouch batteries.
ABSTRACT Carbon/silicon (C/Si) heterojunction solar cells have recently achieved power conversion efficiencies exceeding 23% for small‐area (6 cm²) devices. The development pathway toward these results highlights the critical requirements for engineering efficient contacts and heterojunction structures in next‐generation photovoltaic technologies. If current performance trends continue, C/Si heterojunctions could provide a viable route to affordable, high‐efficiency solar cells. This review examines the main carbon allotropes explored for C/Si junctions, that is, amorphous carbon (a‐C), C₆₀ fullerene, graphene, and carbon nanotubes (CNTs) and evaluates their optoelectronic properties, deposition strategies, and device performance. The a‐C approach enables low‐temperature, scalable processing but suffers from high defect densities and limited carrier mobility. Fullerene derivatives offer favorable energy‐level alignment for electron extraction, yet their low conductivity and photochemical instability remain obstacles. Graphene provides reasonable optical transparency, mechanical flexibility, and a tunable work function; however, its relatively high sheet resistance, parasitic optical absorption, and interface recombination cast doubt over its use in high‐efficiency solar cells. By contrast, CNTs combine outstanding electrical conductivity, one‐dimensional carrier transport, and simple solution‐based fabrication, supporting efficient charge separation and extraction when integrated with optimized passivation layers. As a result, CNT/Si heterojunctions consistently outperform other carbon‐based architectures, positioning CNTs as the leading candidate for future low‐cost, high‐efficiency C/Si photovoltaic devices. The review concludes by outlining research priorities in interface optimization and scalable large‐area processing.
ABSTRACT All‐solid‐state batteries (ASSBs) have emerged as a pivotal direction in next‐generation energy storage, driven by their compelling potential for enhanced safety and superior energy density. Among the key enabling materials, solid polymer electrolytes (SPEs) stand out due to their structural tunability, manufacturing scalability, and robust interfacial contact, offering a viable pathway toward practical ASSBs. This review systematically bridges the gap between molecular‐level design and macroscopic performance of SPEs. It begins by establishing the structure–property relationships underpinning different SPE categories, and then critically assesses conventional and emerging processing techniques in relation to their electrochemical and mechanical performance. Furthermore, the article synthesizes current challenges and strategic solutions for optimizing SPEs, with an emphasis on integrated approaches that balance ionic conductivity, interfacial stability, and processability. By presenting a coherent technological landscape, this work aims to guide the rational design of SPE materials to accelerate the development of reliable, high‐performance ASSBs.
ABSTRACT As global energy demand continues to rise, developing sustainable and clean energy technologies has become an urgent priority. Hydrogen production from seawater electrolysis has attracted growing attention as a cost‐effective and sustainable approach due to the abundance of seawater as a feedstock. However, during seawater electrolysis, both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are strongly influenced not only by catalyst activity but also by the complex composition of seawater. In particular, the presence of chloride ions and alkaline‐earth metal salts such as Ca 2+ and Mg 2+ reduces efficiency compared with freshwater systems, while the competitive chlorine evolution reaction (ClER) compromises oxygen selectivity and accelerates electrode degradation. To address these challenges, designing corrosion‐resistant OER and HER catalysts with high activity and long‐term stability is of great importance. This review provides a comprehensive overview of transition metal‐based catalysts for seawater electrolysis, emphasizing their reaction mechanisms, degradation pathways, and structural instability caused by poor reaction selectivity. Furthermore, we summarize recent advances in improving catalyst durability through electrolyte modification and electrolyzer design optimization. Finally, we outline key material design principles for developing robust anode and cathode catalysts and present prospects for future research. The insights presented here aim to guide the rational design of highly stable, corrosion‐tolerant catalysts for efficient and scalable seawater electrolysis, promoting its practical application in clean energy conversion and storage.
Proton exchange membrane fuel cells (PEMFC) suffer significant voltage degradation at lower Pt loadings on the cathode. Expedited commercialization and sustainable utilization of scarce resources demand highly durable Pt-based electrocatalysts produced via rapid, scalable processes. We present Pt nanoparticles (approximate to 2 nm) embedded in a nanoscale carbon network, produced via controlled-atmosphere flame spray pyrolysis, where native Pt nuclei serve as structural guides for the nanoscale overlayer. The gas-phase-derived porous catalyst exhibits high accessibility to Pt and uncompromised oxygen reduction activity upon activation and demonstrates at least fourfold lower performance loss at high current densities and fivefold lower electrochemical active surface area loss compared to state-of-the-art alternatives in low-Pt-content fuel cells. The strong interfacial coordination between Pt and its surface-grown carbon network, combined with the continuous, favorable structural evolution of the catalyst and catalyst layer, remarkably suppresses Pt degradation mechanisms, including ionomer poisoning and Pt dissolution, facilitates H+ and O2 transport to the catalyst, and ensures sustained performance under harsh fuel cell operating conditions.
ABSTRACT High‐entropy perovskite oxides (HEPOs) are a new frontier in energy materials, where multi‐cation configurational disorder and entropy stabilization enable unmatched structural and functional tuning. This review highlights recent progress in synthesis methods, structural design principles, and defect engineering, demonstrating how configurational, vibrational, and electronic entropy interact to enhance phase stability, ionic and electronic transport, and catalytic activity. Key applications are explored, including catalytic processes such as the oxygen evolution reaction (OER), the oxygen reduction reaction (ORR), and the carbon dioxide reduction reaction (CO 2 RR), as well as electrochemical energy storage in Li/Na‐ion batteries, supercapacitors, and metal–air systems. This review also emphasizes how emerging in situ and operando characterization, combined with computational modeling, has advanced understanding of the mechanisms underlying dynamic structural, redox, and defect evolution in HEPOs, creating a framework linking synthesis strategies to functional performance. Overall, these advances position HEPOs as a flexible and scalable platform for next‐generation energy conversion and storage technologies.
Poly(vinylidene fluoride) (PVDF)-based solid polymer electrolytes (SPEs) containing residual solvents are promising candidates for solid-state batteries due to their high ionic conductivity, which arises from enhanced lithium salt dissociation and conformational regulation of the polymer matrix. However, the role of the polymer matrix has been confined to facilitating bulk conduction of Li+, while the influence of polymer polarity on the behavior of residual solvents and their impact on electrode/SPE interfacial chemistry remains insufficiently understood. Here, we introduce the concept of an ionic environment, which extends the conventional solvation structure model by incorporating the role of polymer polarity in governing Li+ coordination. Atomic-scale simulations and experimental characterizations reveal that, compared with PVDF, the highly polar P(VDF-TrFE) establishes an ionic environment where residual DMF and FSI- strongly interact with the polymer, facilitating the desolvation of Li+ from DMF and FSI-. In addition, the higher binding affinity of P(VDF-TrFE) toward DMF promotes a more uniform residual DMF distribution within the SPE and mitigates its decomposition, which in turn enhances the electrochemical performance and interfacial stability of solid-state cells. By elucidating the previously underappreciated effects of polymer polarity, this work provides guiding principles for the rational design of advanced SPEs.
ABSTRACT The rapid evolution of perovskite photodetectors is transforming the field of photon detection, positioning these materials at the forefront of next‐generation optoelectronic and photonic technologies. Leveraging their exceptional bandgap tunability, high carrier mobility, and strong light–matter interaction, perovskite systems are enabling multifunctional photodetectors capable of adaptive sensing, real‐time signal processing, and intelligent, context‐aware operation. This review presents a comprehensive overview of the recent breakthroughs that have propelled perovskite photodetectors from early laboratory demonstrations to advanced platforms suitable for high‐performance imaging, ultrafast optical communication, and emerging neuromorphic and autonomous systems. Particular attention is devoted to material innovations that mitigate persistent challenges in operational and environmental stability, as well as to novel device architectures engineered for integrated functionalities such as spectral discrimination, polarization sensitivity, and on‐chip data processing. We also outline the technological roadmap for translating these innovations into scalable, manufacturable devices. Finally, we critically examine the remaining hurdles‐long‐term reliability, large‐area fabrication, lead toxicity, and the seamless integration of memory, logic, and learning capabilities—and discuss strategic directions for realizing intelligent, robust, and sustainable perovskite photodetectors as cornerstone components of future optoelectronic infrastructures.
ABSTRACT Biochar has emerged as a useful and adaptable source of carbon for supercapacitor electrodes. Its value comes from the way biomass chemistry, thermal conversion, and activation conditions shape the resulting pore network, surface groups, and degree of carbon ordering. These features govern how ions enter the structure, how charge is stored, and how the electrode behaves under cycling. Although substantial progress has been made, key limitations remain, such as variations in feedstock composition, restricted control over hierarchical porosity, modest intrinsic conductivity, and uncertainty regarding how heteroatom groups interact with the pore walls during charge storage. This review examines these issues by connecting electrochemical behavior to the underlying material structure. It describes how the proportions of cellulose, hemicellulose, lignin, and proteins influence carbon yield and aromaticity, how carbonization and activation shape micro, meso, and macropores, and how nitrogen, phosphorus, sulfur, and oxygen groups participate in fast surface redox reactions. Studies on composites, flexible electrodes, and high‐rate devices are compared with reference carbons, such as activated carbons, graphene, and carbon nanotubes, to clarify practical gains rather than isolated outcomes. Wherever possible, reported capacitance and cycling behavior are related to pore size distributions, defect densities, and the nature of surface functionalities. The review also discusses recent work on cost analysis, life‐cycle assessments, and machine learning tools that help predict yield, porosity, composition, and capacitance. Together, these findings outline the scientific and technical considerations required to improve reliability, support scalable production, and guide the development of biochar‐based electrodes for next‐generation supercapacitors.
Hard-carbon anodes for sodium-ion batteries are often constrained by low initial Coulombic efficiency, severe interfacial polarization, and sluggish Na+ kinetics, especially when porosity engineering amplifies electrolyte consumption. This work reports a heteroatom-engineered hard carbon (UNMC) that couples molecular-level crosslinking regulation with ultrahigh N/O doping to program a chemically graded solid-electrolyte interphase (SEI) and accelerate Na+ storage. A uniform UF/MA/2-MIM crosslinked network, reinforced by Zn & sup2;(+) coordination, is converted via hydrothermal restructuring, pre-oxidation, and carbonization into a nanosheet-bundle framework featuring moderately expanded turbostratic domains and dense closed nanopores. UNMC delivers a high first-cycle charge capacity of 437.1 mAh g-1 with an initial coulombic efficiency of 80.93%, sustains 367.32 mAh g-1 after 2000 cycles at 0.1 A g-1, and maintains 178.89 mAh g-1 over 10,000 cycles at 10 A g-1. A pre-sodiated UNMC//Na3V2(PO4)(3) full cell achieves 95.14% initial Coulombic efficiency and an active-material-level energy density of 200 Wh kg-1. Depth-resolved/in situ characterizations and DFT consistently indicate that N/O synergy strengthens Na+ anchoring, promotes an inorganic-rich inner SEI, and suppresses polarization, establishing a transferable structure-interface co-design paradigm for durable, high-rate hard-carbon anodes.
Solar-driven electrochemical conversion of CO2 into multi-carbon products offers a promising pathway for renewable energy storage, yet its efficiency is essentially constrained by the mismatch between the solar energy spectrum and the energy demands of CO2 electrolysis. Here, a full-spectrum solar photovoltaic-thermal tandem system is proposed for CO2-to-acetate conversion: a high-temperature solid oxide electrolysis cell (SOEC) first converts CO2 to CO, followed by electrochemical reduction of CO to acetate. Short-wavelength solar energy generates photovoltaic electricity to drive electrochemical reactions, while long-wavelength solar energy is used for concentrated solar thermal collection to heat the high-temperature SOEC device and preheat reactants. Two reference systems were also analyzed: one is direct electrocatalytic CO2 reduction to acetate, and the other is water electrolysis to produce hydrogen, which then undergoes a thermochemical reaction with CO2 to generate acetate. Under representative operating conditions (cutoff wavelength of 900 nm and concentration ratio of 5000), the proposed system achieves a solar-to-acetate efficiency of 15.8%, representing improvements of 11.2 and 8.3 percentage points compared with two reference systems, owing to effective matching between thermal and electrical energy supply and demand. These results underscore that a tandem system integrated with full-spectrum solar energy is critical to overcoming efficiency limitations in solar-driven CO2 conversion.
ABSTRACT As a crucial component of rechargeable batteries, electrolytes significantly determine interfacial characteristics and device performance. The development of advanced electrolytes relied on empirical trial‐and‐error and theoretical calculations mainly. Recently, the data‐driven methods represented by machine learning (ML) have made progress in the materials field. However, interdisciplinary barriers and the multicomponent complexity of electrolyte systems impede the advancement of artificial intelligence (AI) in the electrolyte domain. Therefore, examining the application of ML methods in liquid and solid‐state electrolytes to bridge the gap between battery science and data science is necessary. Firstly, this review summarizes the main technical routes and ion transport mechanisms of different electrolytes. Secondly, the basic concepts and suitable tasks of various ML algorithms are outlined. Following this, we investigate mainstream representation methods for electrolyte materials, which transfer material structures to machine‐readable input vectors. Subsequently, representative application cases of ML in liquid and solid‐state electrolytes are summarized. Finally, a perspective on the current challenges and future frontiers of AI‐driven electrolyte research is provided. This review offers a deep understanding of this interdisciplinary field, providing intelligent insight for advanced battery electrolyte innovation.
ABSTRACT The catalytic conversion of C 1 molecules (CO, CO 2 , CH 4 , CH 3 OH, CH 2 O, etc.) is a pivotal route toward carbon neutrality and a sustainable energy future. Traditional thermocatalysis relies on fossil‐fuel combustion to supply heat, but this approach suffers from low heat‐transfer efficiency, high energy consumption, and catalyst deactivation. In contrast, Joule‐heated catalysis directly energizes conductive catalysts with electric current, enabling in situ, spatially uniform heating and the coupling of electric and thermal fields, thereby enhancing C 1 molecule conversion and overall energy efficiency. This review systematically elucidates the fundamental principles of Joule‐heated catalysis and highlights recent advances in its application to CO 2 methanation, hydrogen production via reforming, and the oxidation of formaldehyde and CO. From the viewpoints of enhanced heat transfer, electron dynamics, and band‐structure modulation, the mechanisms underlying electrothermal synergy are comprehensively analyzed. Furthermore, the existing challenges and future prospects of Joule‐heated catalysis are discussed in terms of theoretical understanding, material design, and industrial implementation. This work aims to provide insights and guidance for advancing both the fundamental research and large‐scale application of Joule‐heated catalytic technologies.
ABSTRACT The deployment of carbon capture, utilization, and storage (CCUS) has become a key approach to mitigating the overwhelming greenhouse effects. Porous carbon materials (PCMs) are a range of promising carbon capture candidates due to their affordability, environmental friendliness, and resistance to moisture. Numerical studies on the effect of porous structures on CO 2 uptake exist; however, these results still need to be systematically analyzed to better understand how their pore structures affect the adsorption properties. This work comprehensively summarizes pore structure construction strategies and elucidates the ideal pore structure features conducive to CO 2 adsorption, focusing on the synergistic effects of porous structures on the CO 2 adsorption capacity and CO 2 /N 2 selectivity. A specific surface area exceeding 1000 m 2 /g and a total pore volume higher than 0.5 cm 3 /g are sufficient for achieving high CO 2 adsorption capacity without necessitating excessively high values. A high proportion of narrow‐micropores (<0.7 nm) volume and a low proportion of mesopores (2–10 nm) volume are crucial for their high capacity, high selectivity, and fast diffusion. Furthermore, adsorption conditions significantly influence the adsorption capacity of narrow micropores. Precision pore engineering, condition‐responsive functional pore structure, and AI‐driven material design are recommended as research frontiers for advancing PCMs for carbon capture.
ABSTRACT Gallium oxide (Ga 2 O 3 ), which provides ideal band alignment with Cu 2 O, is one of the most effective buffer‐layer materials for enhancing photovoltage. However, Ga 2 O 3 deposition has thus far relied exclusively on atomic layer deposition, which requires expensive and commercially limited precursors, limiting its scalability. In this study, we propose a new electrochemical approach for the atomically conformal deposition of Ga 2 O 3 buffer layers based on the use of gallium nitrate as a precursor and a Cu 2 O‐catalyzed nitrate reduction reaction. This approach promotes the localized generation of hydroxide ions at the Cu 2 O surface, enabling the cathodic electrodeposition of uniform Ga 2 O 3 films at room temperature without high‐temperature annealing. Electrochemically deposited Ga 2 O 3 ( e ‐Ga 2 O 3 ) significantly improved both the onset potential (> 1.0 V RHE ) and photocurrent density (~4 mA cm −2 at 0.6 V RHE ) of Cu 2 O by suppressing charge recombination. When integrated into an all‐oxide tandem photoelectrochemical device with a BiVO 4 ‐based photoanode, the optimized Cu 2 O/ e ‐Ga 2 O 3 photocathode achieved a solar‐to‐hydrogen efficiency of 3.80% under bias‐free conditions and demonstrated stability for over 60 h. This study presents a low‐temperature and cost‐effective route for developing high‐performance Cu 2 O photocathodes for efficient solar‐driven water splitting.
ABSTRACT Based on the Sabatier principle, catalysts with optimal catalytic activity can be engineered by the selection of the appropriate metal and support, along with precise regulation of the interaction strength between metal nanoparticles and the support materials. Besides the traditional Sabatier principle related to the catalytic activities of the electrocatalyst, a new Sabatier principle was proposed to manifest the volcano shape of the metal–support interaction to durability. Although considerable attention has been devoted to the Sabatier principle for predicting catalytic activity, its implications for the stability and durability of electrocatalysts for the oxygen reduction reaction (ORR) have not been systematically examined. In this review, we will introduce the fundamentals of the Sabatier principle and focus on the novel application frontier of the Sabatier principle of tailoring metal–support interactions for durable electrocatalysis. The application includes a critical analysis of both supported catalysts (such as single‐atom catalysts, nano‐islands, and intermetallics) and unsupported catalyst systems (such as supportless and surrounded catalysts). Analysis of the Sabatier principle ensures optimal catalytic activity by balancing reactant adsorption and desorption, whereas metal–support interactions fine‐tune durability against sintering through electronic and structural effects. The integration of the Sabatier principles is pivotal for the rational design of efficient, stable, and selective catalysts, thereby advancing technologies for industrial and environmental sustainability.
