Exploiting its exceptional structural tunability and digital manufacturing capability, 3D printing emerges as a transformative technique for the rational design and scalable fabrication of catalytic electrodes tailored for advanced electrochemical energy systems. In this study, hierarchically porous, self-supporting carbon electrodes were fabricated via 3D printing technique in combination with the sequential conformal carbonization. An optimized polymerizable ionic liquid-based ink was employed to produce a 3D printed polymer gel, which was subsequently functionalized with B-containing species. The as-prepared gel was then pyrolyzed to yield B/N-co-doped carbon electrodes with a high surface area possessing micropores, mesopores and macropores. The metal-free cathode demonstrated good performance in electrocatalytic CO₂ reduction, producing syngas with tunable H₂/CO ratios ranging from 0.37 to 2.6, thereby catering to diverse application requirements. This study naturally integrates 3D printing with ionic-liquid chemistry to fabricate customizable metal-free carbon electrodes for efficient CO₂-to-syngas conversion, offering a Power-to-X route to store intermittent renewable electricity as chemical energy and to deliver tunable H₂/CO syngas suitable for downstream fuel and chemical synthesis.

Direct air capture (DAC) is an emerging technology that supports mitigating climate change. However, its large-scale deployment is hindered by high energy demands and material costs. In this study, we present a novel porous sorbent material for DAC using 3D-printed activated carbon monoliths functionalized with an aminosilane compound. The monoliths were fabricated via direct ink writing and subsequently modified with 3-aminopropyltriethoxysilane (APTES) to introduce chemisorption sites for CO₂. Structural and chemical analyses confirmed successful grafting of amines without compromising the monolithic architecture. The resulting monoliths demonstrated enhanced CO₂ uptake at atmospheric concentrations (0.25 mmol g⁻¹ at 0.04 kPa). IR spectroscopy revealed that the functionalized monoliths chemisorb CO₂ from ambient air as ammonium carbamate. Chemisorbed CO₂ can be desorbed at a temperature of 75°C, indicating a low energy requirement for a DAC process. To the best of our knowledge, this paper is the first published application of aminosilane-functionalized activated carbon for DAC, highlighting its potential as a cost-effective and scalable sorbent material.

Conventional LiFePO₄ (LFP) cathodes employing poly(vinylidene fluoride) (PVDF) as binder exhibit relatively stable cycling performance but suffer from poor ionic conductivity, limited rate capability, restricted cycling stability at high current densities, as well as environmental concerns about the high fluorine content of PVDF. Here, we introduce an anion-cluster-mediated Li⁺ hopping mechanism in a series of newly synthesized and multifunctional poly(ionic liquid) (PIL) binders that can enable high-rate performance with an accelerated Li⁺ transport by 140–200%, meanwhile reducing the fluorine content by 60%. The counteranion aggregation along the PIL backbones can attract and promote the Li⁺ migration based on comprehensive validation of nuclear magnetic resonance spectroscopy, cyclic voltammetry and molecular dynamics simulations. The optimized LFP-PIL cathodes deliver superior high-rate performance (a capacity of 100 mAh·g^–1 at 15C) and cycling stability (95.5% capacity retention after 500 cycles at 5C). Furthermore, by integrating the chemistry-informed machine learning with experimental validation, we establish a molecular structure design methodology for next-generation PIL binders. This work provides both mechanistic insight and a generalizable design framework for high-performance and sustainable lithium cathode materials.

Electrocatalytic glycerol oxidation reaction (GOR) presents a sustainable pathway for value-added chemical production but is hindered by unbalanced adsorption kinetics of reactants and a lack of rational catalyst design principles. This study introduces a descriptor-guided dual-site engineering strategy using transition metal (TM) doped α-MnO₂ (Mn, Fe, Co, Ni, Cu, or Zn) as model catalysts. Theoretical analysis identifies two critical electronic descriptors: the TM d-band center, influencing hydroxide (OH⁻) adsorption; and the Mn d_z² orbital center, affecting interactions with C/O intermediates. Among the series, Ni doping fine-tunes electronic coupling within the corner-oxygen-bridged TM–O–Mn moiety, synchronizing the adsorption kinetics of OH⁻ and glycerol. Therefore, Ni-MnO₂ exhibits the highest GOR activity, achieving 50 mA F⁻¹ at merely 1.35 V versus RHE, high formate productivity, and exceptional long-term stability (>88 h). These insights establish key electronic parameters for catalyst optimization, offering strategic guidance to enhance catalytic activities in complex reactions.

A wealth of theoretical studies demonstrates p-type MoS2 (p-MoS2) as a promising candidate for carbon dioxide (CO2) detection at room temperature. Its applications are retarded by issues associated with its practical chemical synthesis and sensing selectivity. Herein, a chemically tunable strategy is established for in situ growth of p-MoS2 with controlled thickness and n-/p-type transition on N- and Fe-enriched carbon (FeNC) nanosheets. The introduced sulfur vacancies (Svacs) enhance the sensitivity to CO2, and the modulated electron distribution suppresses surface oxygen ionization to improve sensing selectivity. The optimized p-type composites can detect CO2 fluctuation levels as low as 50 ppm at room temperature. Density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulations clarify the underlying mechanisms. A visualized machine learning (ML) model is developed using a hybrid ML strategy that generates regression surfaces from linear/nonlinear data. Through this model, a single sensor accurately discriminates CO2 from interfering and predicts its concentration and humidity with accuracies exceeding 95%. An intelligent sensing system capable of environmental monitoring and tracking exhaled CO2 is demonstrated. The measured fluctuations strongly correlate with physiological indicators, underscoring their potential for non-invasive health monitoring and medical diagnostics.

MXenes have gathered immense scientific attention due to their unique combination of high electronic conductivity, hydrophilicity, and reduced dimensionality. While considerable advances in synthetic methodologies, achieving rapid, high-yield production of dispersible monolayer MXenes with controllable in-plane structure remains a daunting challenge. Herein, we report an ultrafast radical-intensified selective etching (RISE) tactic that enables one-step mild synthesis of monolayer Ti₃C₂T_x MXene bearing customized in-plane nanoholes with near-quantitative etching efficiency (∼99.9%) within merely 3 h. By fine-tuning the dosage of H₂O₂, which generates hydroxyl radicals (·OH) in situ, defect-lean monolayer MXene was made in a high yield of 81.6%. Liters of such colloidal dispersion of monolayer MXene were obtained within hours, which could be readily processed into conductive films with improved oxidation resistance. Mechanistic studies reveal that the RISE protocol follows a radical-driven redox pathway fundamentally distinct from traditional proton-mediated etching routes. As a proof of concept, holey MXene-derived conductive films demonstrated an exceptional desalination capacity of 32.71 mg g⁻¹ in capacitive deionization, outperforming most pure MXene-based electrode materials. Our method can potentially revolutionize the prevailing wet chemical etching protocol used for a decade for yielding monolayer MXene and establishes a swift pathway toward customizable MXene architectures for energy and environmental applications.

The catalyst-electrolyte interface (CEI) fundamentally plays a vital role in governing the activity and kinetics of electrochemical reactions relevant to chemical manufacturing, energy devices, and other applications. However, state-of-the-art observations of the CEI reveal structural evolution during reactions, leading to challenges in elucidating the true structure-performance relationships and thereby hindering the rational design of high-performance catalytic systems for emerging applications. This perspective highlights advances in operando X-ray spectroscopies that enable a mechanistic understanding of dynamic CEI across electronic-, atomic-, and nanoscale levels. We highlight the challenges and opportunities regarding X-ray spectroscopies for understanding, predictive design, and durability engineering of the CEI in heterogeneous electrocatalysis.

A set of cationic photoresponsive monomers is synthesized from a phenylazopyrazol dye by N-methylation followed by ion exchange and is converted by free radical polymerization to the corresponding arylazopyrazolium-bearing polycations. By an appropriate choice of the anion, ionic liquid behavior can be implemented in the monomers. Both the monomers and the polymers retain the outstanding spectroscopic properties of their noncharged arylazopyrazole analogs regarding their quantitative reversible E-Z (trans-cis) photoisomerization by alternating irradiation with ultraviolet (UV) and green light. At this, they maintain a rather long half-life of the metastable Z-isomer despite their much more polar character compared to the noncharged chromophore. Furthermore, the polymers show a characteristic solubility behavior in water. While they dissolve only at elevated temperatures, thus showing an upper critical solution temperature, the polymers remain in solution at temperatures as low as 4 degrees C. Only rapid cooling or freezing and subsequent thawing induce macroscopic phase separation. Characterization by 1H NMR spectroscopy and by measurements of the zeta-potential, the ion mobility, the surface tension, and cryogenic scanning electron microscopy (cryo-SEM) suggests that the monomer is a hydrotrope and that the particular solution behavior is related to the self-assembly of the dye moieties in the aqueous environment.

Electrode binders, typically regarded as passive mechanical additives, in fact define a solid-liquid interface that governs charge screening and local proton-electron transfer kinetics. Here we show that fluorine-free poly(ionic liquid)s (PILs) operate as solid-state electrolyte layers whose intrinsic electric fields modulate the competition between electrochemical hydrogenation (ECH) and the hydrogen evolution reaction (HER). When applied to Pd-C catalysts, PIL binders reshape the electric double layer by repelling alkali cations and modulating interfacial pH, which change the kinetics of proton-electron transfer, suppress Tafel hydrogen recombination and promotes selective coupling of adsorbed hydrogen with organic substrates. The resulting electrodes achieve up to fivefold higher ECH yields and fourfold greater Faradaic efficiencies than those based on Nafion or PVDF in three different pH values 0.6, 5.2, and 13, while simultaneously reducing Pd leaching. These findings identify the polymer additives more than a binder, but rather as an active field-modulating medium. A solid analogue of the electrolyte double layer, thus extending classical electrolyte-effect concepts to polymer-confined interfaces and offering a strategy for binder-controlled interfacial design in electrosynthetic systems.

Achieving both high energy storage and superior rate capability in MXene-based aqueous supercapacitors remains challenging. While Ti3C2Tx-MXene demonstrates exceptional capacitance in H2SO4, its energy storage is limited by a narrow voltage window (<1 V). In contrast, neutral electrolytes enable a wider voltage window (>1 V), but compromise specific capacitance and rate performance. To overcome this trade-off, we develop an ultrafast microwave-assisted acid etching strategy that produces holey-crumpled MXene dispersions from pristine MXene within minutes. These dispersions are assembled into hierarchically porous MXene hydrogel-electrodes through controlled vacuum filtration in a remarkably short time. In an engineered electrolyte containing LiCl and AlCl3, the resulting MXene electrodes exhibit superb pseudocapacitance, delivering a specific capacitance of 248.7 F g−1 at 10 mV s−1 and excellent capacitance retention of 60.7% at 2000 mV s−1 within a wide potential window of 1.3 V. This impressive supercapacitor performance stems from multi-scale porosity that enhances electrolyte infiltration and ion transport, combined with mixed-ion charge storage in LiCl/AlCl3 electrolyte, where protons and mixed cations synergistically balance pseudocapacitance and rate capability. This work establishes the fastest route to holey MXene dispersions and showcases how structural hierarchy and mixed-ion electrolytes collectively deliver high capacitance and rate performance in MXene supercapacitors.