The electrochemical CO₂ reduction reaction (CO₂RR) offers a dual benefit: closing the carbon cycle, while simultaneously storing renewable energy in chemical bonds. Carbon-based catalytic materials, as exceptional electrocatalysts, exhibit excellent conductivity, robust stability, tunable surface functionality, and unique capability to construct metal–carbon synergistic interfaces. In CO₂RR, carbon-based catalytic materials stand out duple critical functions among series roles: (i) active site engineering governing intrinsic activity, and (ii) mass/charge transport dictating effective active sites utilization. Synergistic optimization of these elements constitutes the “catalytic activity-transport kinetics” binary model for performance enhancement. This review dissects active sites design via defect engineering, heteroatom doping, and metal-carbon composites, coupled with mass/charge transport engineering through electronic conductivity modulation, surface hydrophobicity control, and hierarchical porosity optimization. We further critically examined the challenges and opportunities in CO₂RR, with a focus on the integrated design bottlenecks constraining high-performance catalyst development. By integrating these dual engineering paradigms, structure–performance correlations were established to guide the rational design of carbon-based CO₂RR catalysts.

Carbon dioxide (CO₂) is not only a greenhouse gas but also an abundant carbon resource. CO₂ hydrogenation from electrocatalysis and thermocatalysis to high-value-added chemicals has attracted wide attention. The development of a catalyst was critical in the reaction, and the key is the innovation of its synthesis strategy. Carbon materials are widely used in CO₂ hydrogenation because of their unique physical and chemical properties. Carbon species could play many roles during catalyst preparation and reaction, not only as bulk catalysts but also as structure modifiers of catalyst, support of catalyst, and electronic regulator of catalyst. In this review, the developmental strategy of catalysts by using a carbon species-assisted method in our research group was summarized, which can be applied to CO₂ thermochemical and electrochemical hydrogenation. This review aims to provide insights into CO₂ hydrogenation through the design of carbon-based catalysts.

Silicon monoxide (SiO) is widely recognized as a promising anode material for next-generation lithium-ion batteries. Owing to its metastable amorphous structure, SiO exhibits a highly complex degree of crystallization at the microscopic level, which significantly influences its electrochemical behavior. As a consequence, accurately regulating the crystallization of SiO, and further establishing the relationship between crystallinity and electrochemical performance are very critical for SiO anodes. In this article, carbon-coated SiO materials with different crystallinity degrees were synthesized using lithium hydroxide monohydrate (LiOH·H₂O) as a structural modifier to reveal this rule. Additionally, moderate amount of LiOH·H₂O addition results in the forming of an oxygen-rich shell, which effectively inhibits the inward migration of oxygen atoms on the SiO surface and suppresses volume expansion. However, the crystallinity of SiO will gradually enhance and the crystalline phase appears with increasing the amount of LiOH·H₂O, which will generate a deteriorative Li⁺ diffusion kinetic. After balancing the above two contradictions, a mass fraction of 1% LiOH·H₂O for the additive yielded SiO@C-1, characterized by optimal crystallinity. SiO@C-1 demonstrates exceptional long-cycle stability with 74.8% capacity retention after 500 cycles at 1 A·g⁻¹. Furthermore, it achieves a capacity retention of 52.2% even at a high density of 5 A·g⁻¹. This study first reveals the relationship between SiO crystallinity and electrochemical performance, which efficiently guides the design of high-performance SiO anodes.

Proton exchange membrane fuel cells (PEMFCs) are efficient and zero emission energy conversion technology with promising application prospects towards carbon neutrality. The PEMFC's performance is largely affected by the poor water management, which is a substantial concern for long term durability. Herein, we overview the water management problems in PEMFCs, such as flooding and dehydration of membrane electrode assembly and analyze the causes and their impacts on the device performance. Major problems such as flooding impedes the gas transport and electrode reactions, while dehydration increases the membrane resistance and hinders proton transport. We have thoroughly overviewed several electrochemical and physicochemical diagnostic techniques for water management in PEMFCs. Additionally, material development and optimization approaches for the flow field structural design are explored in order to improve mass transport and wetting characteristics for optimized water management. Therefore, it is anticipated that this review will provide insights into the effective operation of PEMFCs as well as practical guidance for resolving water management issues in PEMFCs and associated technologies, like PEM water and CO₂ electrolyzers.

Photocatalytic oxidation of methane to value-added chemicals is a promising process under mild conditions, nevertheless confronting great challenges in efficiently activating C–H bonds and inhibiting over-oxidation. Herein, we propose a comprehensive strategy for the selective generation of reactive oxygen species (ROS) by regulating the sizes and facets of Au nanoparticles loaded on ZnO. For photocatalytic methane oxidation at ambient temperature, a high oxygenates yield of 36.4 mmol·g⁻¹·h⁻¹ with a nearly 100% selectivity has been achieved over the optimized 1.0% Au/ZnO-9.6 (1% Au with (111) facet and 9.6 nm size on ZnO) photocatalyst, exceeding most reported literatures. Mechanism investigations reveal that 1.0% Au/ZnO-9.6 with the medium size and Au (111) facet guarantees the favourable formation of superoxide radicals (·OOH) through mild oxygen reduction, ultimately leading to excellent photocatalytic methane oxidation performance. This work provides some guidance for the delicate design of photocatalysts for efficient photocatalytic methane oxidation and oxygen utilization.

The commercialization of lithium-sulfur (Li-S) batteries faces several bottlenecks, and the major two of which are the shuttle effect of polysulfides and the wild growth of Li dendrites, responsible for fast capacity decay and severe safety issues. As an essential component of Li-S batteries, the structure and properties of the separators are closely related to the above problems, and the exploration of multifunctional separators is highly sought-after. Herein, an integrated separator composited of defective graphene and polyimide (DG-PI) was innovatively fabricated by electrospinning combined with the laser-induced carbonization strategy. The all-in-one compact architecture with well-interconnected channels shows superior mechanical and thermal stability and wettability. More importantly, the PI nanofibers containing N–/O– functional groups can induce the uniform deposition of lithium on the anode surface, while the DG framework with abundant pentagonal/heptagonal rings and vacancies can strongly trap polysulfides and accelerate polysulfide transformation on the cathode side. The strong chemical interaction between the insulative PI layer and the conductive DG layer modulates the surface charge distribution of each other, leading to more prominent contributions to restraining lithium dendrites and shuttle effect. Therefore, the Li-S batteries based on the integrated DG-PI separators afford an excellent performance in protecting lithium anode (stable cycles of 200 h at 5 mA·cm⁻²) and good cycling stability with a low capacity decay of 0.05% per cycle after 700 cycles at 1 C. This work offers a new design concept of multifunctional Li-S battery separators and broadens the application scope of laser micro-nano fabrication technology.

It is crucial to construct an efficient catalyst with high activity and excellent selectivity for realizing CO₂ electroreduction reaction (CO₂ER) to high-value-added chemicals, especially the C2 products. Density functional theory (DFT) provides a powerful tool for investigating the promotional effect on C2 selectivity of finely tuned catalyst structures, which is currently difficult to control using experimental techniques, such as interatomic distances. In the work, 5 Cu₂O catalyst models are constructed with different Cu-Cu atomic spacing (d_Cu-Cu). The results of DFT calculations show that adjusting the d_Cu-Cu can effectively tailor the electronic structures of active sites, enhance catalytic activity, and improve product selectivity. Specifically, the Cu atom pair spaced at d_Cu-Cu = 2.5 Å could optimize the adsorption configuration of *CO and enhance the binding strength of *CO, thus improving *CO adsorption energy and reducing the energy barrier of C-C coupling. The work proves the feasibility of spacing effect in enhancing the C₂H₄ selectivity of CO₂ER and provides a new idea for the catalyst modification for other reactions of polyprotons-coupled electrons.

Energy density, the Achilles’ heel of aqueous supercapacitors, is simultaneously determined by the voltage window and specific capacitance of the carbon materials, but the strategy of synchronously boosting them has rarely been reported. Herein, we demonstrate that the rational utilization of the interaction between redox mediators (RMs) and carbon electrode materials, especially those with rich intrinsic defects, contributes to extended potential windows and more stored charges concurrently. Using 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxyl (4OH-TEMPO) and intrinsic defect-rich carbons as the RMs and electrode materials, respectively, the potential window and capacitance are increased by 67% and sixfold in a neutral electrolyte. Moreover, this strategy could also be applied to alkaline and acid electrolytes. The first-principle calculation and experimental results demonstrate that the strong interaction between 4OH-TEMPO and defect-rich carbons plays a key role as preferential adsorbed RMs may largely prohibit the contact of free water molecules with the electrode materials to terminate the water splitting at elevated potentials. For the RMs offering weaker interaction with the electrode materials, the water splitting still proceeds with a thus sole increase of the stored charges. The results discovered in this work could provide an alternative solution to address the low energy density of aqueous supercapacitors.

The performance of lithium-sulfur battery is restricted by the lower value of electrode conductance and the sluggish LiPSs degradation kinetics. Unfortunately, the degradation rate of polysulfides was mostly attributed to the catalytic energy barrier in previous, which is unable to give accurate predictions on the performance of lithium-sulfur battery. Thereby, a quantitative framework relating the battery performance to catalytic energy barrier and electrical conductivity of the cathode host is developed here to quantitate the tendency. As the model compound, calculated-Ti₄O₇ (c-Ti₄O₇) has the highest comprehensive index with excellent electrical conductivity, although the catalytic energy barrier is not ideal. Through inputting the experimental properties such as impedance and charge/discharge data into the as-build model, the final conclusion is still in line with our prediction that Ti₄O₇ host shows the most excellent electrochemical performance. Therefore, the accurate model here would be attainable to design lithium-sulfur cathode materials with a bottom–up manner.

CO2 electrochemical reduction reaction (CO2RR) to formate is a hopeful pathway for reducing CO2 and producing high-value chemicals, which needs highly selective catalysts with ultra-broad potential windows to meet the industrial demands. Herein, the nanorod-like bimetallic In2O3/Bi2O3 catalysts were successfully synthesized by pyrolysis of bimetallic InBi-MOF precursors. The abundant oxygen vacancies generated from the lattice mismatch of Bi2O3 and In2O3 reduced the activation energy of CO2 to *CO2·− and improved the selectivity of *CO2·− to formate simultaneously. Meanwhile, the carbon skeleton derived from the pyrolysis of organic framework of InBi-MOF provided a conductive network to accelerate the electrons transmission. The catalyst exhibited an ultra-broad applied potential window of 1200 mV (from −0.4 to −1.6 V vs RHE), relativistic high Faradaic efficiency of formate (99.92%) and satisfactory stability after 30 h. The in situ FT-IR experiment and DFT calculation verified that the abundant oxygen vacancies on the surface of catalysts can easily absorb CO2 molecules, and oxygen vacancy path is dominant pathway. This work provides a convenient method to construct high-performance bimetallic catalysts for the industrial application of CO2RR.