Switchable radiative cooling/heating holds great promise for mitigating the global energy and environmental crisis. Here, we reported a cost-effective, high-strength Janus film through surface optical engineering waste paper with one side decorated by a hydrophobic polymeric cooling coating consisting of micro/nanopore/particle hierarchical structure and the other side coated with hydrophilic MXene nanosheets for heating. The cooling surface demonstrates high solar reflectivity (96.3%) and infrared emissivity (95.5%), resulting in daytime/nighttime sub-ambient radiative cooling of 6°C/8°C with the theoretical cooling power of 100.6 and 138.5 W m^–2, respectively. The heating surface exhibits high solar absorptivity (83.7%) and low infrared emissivity (15.2%), resulting in excellent radiative heating capacity for vehicle charging pile (∼6.2°C) and solar heating performance. Impressively, the mechanical strength of Janus film increased greatly by 563% compared with that of pristine waste paper, which is helpful for its practical applications in various scenarios for switchable radiative thermal management through mechanical flipping. Energy-saving simulation results reveal that significant total energy savings of up to 32.4 MJ m^–2 can be achieved annually (corresponding to the 12.4% saving ratio), showing the immense importance of reducing carbon footprint and promoting carbon neutrality.

Strain effects have garnered significant attention in catalytic applications due to their ability to modulate the electronic structure and surface adsorption properties of catalysts. In this study, we propose a novel approach called “similar stacking” for stress modulation, achieved through the loading of Co₂P on Ni₂P (Ni₂P/Co₂P). Theoretical simulations reveal that the compressive strain induced by Co₂P influences orbital overlap and electron transfer with hydrogen atoms. Furthermore, the number of stacked layers can be adjusted by varying the precursor soaking time, which further modulates the strain range and hydrogen adsorption. Under a 2-h soaking condition, the strain effect proves favorable for efficient hydrogen production. Experimental characterizations using X-ray diffraction, high-angel annular dark-field scanning transmission election microscope (HAADF-STEM), and X-ray absorption near-edge structure spectroscopy successfully demonstrate lattice contraction of Co₂P and bond length shortening of Co–P. Remarkably, our catalyst shows an ultrahigh current density of 1 A cm^–2 at an overpotential of only 388 mV, surpassing that of commercial Pt/C, while maintaining long-term stability. This material design strategy of similar stacking opens up new avenues of strain modulation and the deeper development of electrocatalysts.

Electrochemical nitrogen looping represents a promising carbon-free and sustainable solution for the energy transition, in which electrochemical ammonia oxidation stays at the central position. However, the various nitrogen-containing intermediates tend to poison and corrode the electrocatalysts, even the state-of-the-art noble-metal ones, which is worsened at a high applied potential. Herein, we present an ultrarapid laser quenching strategy for constructing a corrosion-resistant and nanostructured CuNi alloy metallic glass electrocatalyst. In this material, single-atom Cu species are firmly bonded with the surrounding Ni atoms, endowing exceptional resistance against ammonia corrosion relative of conventional CuNi alloys. Remarkably, a record-high durability for over 300 h is achieved. Ultrarapid quenching also allows a much higher Cu content than typical single-atom alloys, simultaneously yielding a high rate and selectivity for ammonia oxidation reaction (AOR). Consequently, an outstanding ammonia conversion rate of up to 95% is achieved with 91.8% selectivity toward nitrite after 8 h. Theoretical simulations reveal that the structural amorphization of CuNi alloy could effectively modify the electronic configuration and reaction pathway, generating stable single-atom Cu active sites with low kinetic barriers for AOR. This ultrarapid laser quenching strategy thus provides a new avenue for constructing metallic glasses with well-defined nanostructures, presenting feasible opportunities for performance enhancement for AOR and other electrocatalytic processes.

Passive thermal management in electronics has disadvantages of low efficiency and high cost. Herein, experimental and numerical studies on the geometric optimization of a hygroscopic-membrane heat sink (HMHS) are conducted. The HMHS is based on water evaporation from a membrane-encapsulated hygroscopic salt solution, in which pin fins are used for thermal conductivity enhancement. A comprehensive heat and mass transfer model is developed and validated. To obtain the HMHS configuration with the maximum cooling performance, an approach that couples the Taguchi method with numerical simulations is utilized. The contribution ratio of each design factor is determined. Experimentally validated results demonstrate that the maximum temperature reduction provided by the HMHS can be further improved from 15.5°C to 17.8°C after optimization, achieving a temperature reduction of up to 21°C at a fixed heat flux of 25 kW/m² when compared with a similarly sized fin heat sink. Remarkably, the optimized HMHS extends the effective cooling time by ˜343% compared with traditional phase-change materials, achieving a maximum temperature reduction ranging from 7.0°C to 20.4°C. Meanwhile, the effective heat transfer coefficient achieved is comparable with that of forced liquid cooling. Our findings suggest that the proposed cooling approach provides a new pathway for intermittent thermal management, which is expected to be used for thermal regulation of electronics, batteries, photovoltaic panels, and LED lights.

The single-atom M-N-C (M typically being Co or Fe) is a prominent material with exceptional reactivity in areas of catalysis for sustainable energy. However, the formation of metal nanoparticles in M-N-C materials is coupled with high-temperature calcination conditions, limiting the density of M-N_x active sites and thus restricting the catalytic performance of such catalysts. Herein, we describe an effective decoupling strategy to construct high-density M-N_x active sites by generating polyfurfuryl alcohol in the MOF precursor, effectively preventing the formation of metal nanoparticles even with up to 6.377% cobalt loading. This catalyst showed a high H₂ production rate of 778 mL g_cat^–1 h^–1 when used in the dehydrogenation reaction of formic acid. In addition to the high density of the active site, a curved carbon surface in the structure is also thought to be the reason for the high performance of the catalyst.

Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface. However, limitations in the morphology of heterostructures prepared by hydrothermal reactions or molten salt-assisted strategies make it challenging to directly assess charge distribution and evaluate a single interface’s hydrogen evolution reaction (HER) performance. Here, we prepared two-dimensional MoO₂/MoS₂ step heterostructures with a large specific surface area by the chemical vapor deposition method. Surface Kelvin probe force microscopy and electrical transport measurement verified the asymmetric charge distribution at a single interface. By fabricating a series of micro on-chip electrocatalytic devices, we investigate the HER performance for a single interface and confirm that the interface is essential for superior catalytic performance. We experimentally confirmed that the enhancement of the HER performance of step heterostructure is attributed to the asymmetric charge distribution at the interface. This work lays a foundation for designing highly efficient catalytic systems based on step heterostructures.

Silicon-air batteries (SABs) hold significant potential as efficient energy conversion devices due to their high theoretical energy density, theoretical discharge voltage, and favorable energy-to-cost ratios. However, their applicability has been hindered by low output discharge potential, high discharge polarizations, and singular aqueous configuration. To address these, the catalyst with faster oxygen reduction reaction (ORR) kinetic rate, nitrogen-doped carbon materials functionalized with FeMo metal clusters (FeMo-NC), was designed in acid electrolyte and thus high output voltage and energy density SABs with asymmetric-electrolytes have been developed. This innovative design aligns the reaction rates of the cathode and anode in SABs, achieving stable discharge around 1.7 V for 188 h. Furthermore, an all-in-one quasi-solid-state SAB (QSSSAB) was first developed using a suitable acid–base gel electrolyte. This all-in-one QSSSAB showcases good safety, low cost, and portability, with open-circuit voltage of 1.6 V and energy density of 300.2 Wh kg^–1, surpassing the energy density of most previously reported aqueous SABs. In terms of application, these compact all-in-one QSSSABs can provide stable and reliable power support for portable small electronic devices (such as electronic players, diodes, and electronic watches).

Sodium-ion batteries (SIBs) employ P2-type layered transition metal oxides as promising cathode materials, primarily due to their abundant natural reserves and environmentally friendly characteristics. However, structural instability and complex phase transitions during electrochemical cycling pose significant challenges to their practical applications. Employing cation substitution serves as a straightforward yet effective strategy for stabilizing the structure and improving the kinetics of the active material. In this study, we introduce a Ni-rich honeycomb-layered Na_2+xNi₂TeO₆ (NNTO) cathode material with variable sodium content (x = 0, 0.03, 0.05, 0.10). Physicochemical characterizations reveal that excess sodium content at the atomic scale modifies the surface and suppresses phase transitions, while preserving the crystal structure. This results in enhanced cyclic performance and improved electrochemical kinetics at room temperature. Furthermore, we investigate the performance of the NNTO cathode material containing 10% excess sodium at a relatively high temperature of 60°C, where it exhibits 71.6% capacity retention compared to 60% for the pristine. Overall, our results confirm that a preconstructed surface layer (induced by excess sodium) effectively safeguards the Ni-based cathode material from surface degradation and phase transitions during the electrochemical processes, thus exhibiting superior capacity retention relative to the pristine NNTO cathode. This study of the correlation between structure and performance can potentially be applied to the commercialization of SIBs.

Electrocatalytic reduction of nitrate pollutants to produce ammonia offers an effective approach to realizing the artificial nitrogen cycle and replacing the energy-intensive Haber-Bosch process. Nitrite is an important intermediate product in the reduction of nitrate to ammonia. Therefore, the mechanism of converting nitrite into ammonia warrants further investigation. Molecular cobalt catalysts are regarded as promising for nitrite reduction reactions (NO₂^–RR). However, designing and controlling the coordination environment of molecular catalysts is crucial for studying the mechanism of NO₂^–RR and catalyst design. Herein, we develop a molecular platform of cobalt porphyrin with three coordination microenvironments (Co-N₃X₁, X = N, O, S). Electrochemical experiments demonstrate that cobalt porphyrin with O coordination (CoOTPP) exhibits the lowest onset potential and the highest activity for NO₂^–RR in ammonia production. Under neutral, non-buffered conditions over a wide potential range (–1.0 to –1.5 V versus AgCl/Ag), the Faradaic efficiency of nearly 90% for ammonia was achieved and reached 94.5% at –1.4 V versus AgCl/Ag, with an ammonia yield of 6,498 µg h^–1 and a turnover number of 22,869 at –1.5 V versus AgCl/Ag. In situ characterization and density functional theory calculations reveal that modulating the coordination environment alters the electron transfer mode of the cobalt active center and the charge redistribution caused by the break of the ligand field. Therefore, this results in enhanced electrochemical activity for NO₂^–RR in ammonia production. This study provides valuable guidance for designing adjustments to the coordination environment of molecular catalysts to enhance catalytic activity.

Transition metal borides (TMBs) are a new class of promising electrocatalysts for hydrogen generation by water splitting. However, the synthesis of robust all-in-one electrodes is challenging for practical applications. Herein, a facile solid-state boronization strategy is reported to synthesize a series of self-supported TMBs thin films (TMB-TFs) with large area and high catalytic activity. Among them, MoB thin film (MoB-TF) exhibits the highest activity toward electrocatalytic hydrogen evolution reaction (HER), displaying a low overpotential (η₁₀ = 191 and 219 mV at 10 mA cm^–2) and a small Tafel slope (60.25 and 61.91 mV dec^–1) in 0.5 M H₂SO₄ and 1.0 M KOH, respectively. Moreover, it outperforms the commercial Pt/C at the high current density region, demonstrating potential applications in industrially electrochemical water splitting. Theoretical study reveals that both surfaces terminated by TM and B atoms can serve as the active sites and the H* binding strength of TMBs is correlated with the p band center of B atoms. This work provides a new pathway for the potential application of TMBs in large-scale hydrogen production.

Conventional monometallic sulfides are usually conversion or conversion-alloying-dominated anodes, while the sluggish kinetics and severe volume variation greatly hamper their electrochemical properties in sodium-ion batteries. Herein, bimetallic sulfides (V_s-ZnIn₂S₄) are developed with S vacancies, which are verified via electron paramagnetic resonance. A possible reaction mechanism (intercalation–conversion–alloying) is proposed, which is characterized by in situ X-ray diffraction. In addition, the small volume change during (de)sodiation of V_s-ZnIn₂S₄ is also observed by in situ transmission electron microscopy. The V_s-ZnIn₂S₄ anode shows ultrastable and superfast sodium storage performance, such as outstanding long-term cycling durability at 10 A g^–1 (349.6 mAh g^–1 after 2000 cycles) and rate property at 80 A g^–1 (222.7 mAh g^–1). Moreover, the full cell [V_s-ZnIn₂S₄//Na₃V₂(PO₄)₃/C] achieves an excellent property after 300 cycles (185.9 mAh g^–1) at 5 A g^–1, showing significant potential for real-world applications.

Constructing silicon (Si)-based composite electrodes that possess high energy density, long cycle life, and fast charging capability simultaneously is critical for the development of high performance lithium-ion batteries for mitigating range anxiety and slow charging issues in new energy vehicles. Herein, a thick silicon/carbon composite electrode with vertically aligned channels in the thickness direction (VC-SC) is constructed by employing a bubble formation method. Both experimental characterizations and theoretical simulations confirm that the obtained vertical channel structure can effectively address the problem of sluggish ion transport caused by high tortuosity in conventional thick electrodes, conspicuously enhance reaction kinetics, reduce polarization and side reactions, mitigate stress, increase the utilization of active materials, and promote cycling stability of the thick electrode. Consequently, when paired with LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622), the VC-SC||NCM622 pouch type full cell (∼6.0 mAh cm^–2) exhibits significantly improved rate performance and capacity retention compared with the SC||NCM622 full cell with the conventional silicon/carbon composite electrode without channels (SC) as the anode. The assembled VC-SC||NCM622 pouch full cell with a high energy density of 490.3 Wh kg^–1 also reveals a remarkable fast charging capability at a high current density of 2.0 mA cm^–2, with a capacity retention of 72.0% after 500 cycles.

Organic thermoelectric generators (TEGs) are flexible and lightweight, but they often have high electrical resistance, poor output power, and low mechanical durability, because of which their thermoelectric performance is poor. We used a facile and rapid solvent evaporation process to prepare a robust carbon nanotube/Bi_0.45Sb_1.55Te₃ (CNT/BST) foam with a high thermoelectric figure of merit (zT). The BST sub-micronparticles effectively create an electrically conductive network within the three-dimensional porous CNT foam to greatly improve the electrical conductivity and the Seebeck coefficient and reinforce the mechanical strength of the composite against applied stresses. The CNT/BST foam had a zT value of 7.8 × 10^–3 at 300 K, which was 5.7 times higher than that of pristine CNT foam. We used the CNT/BST foam to fabricate a flexible TEG with an internal resistance of 12.3 Ω and an output power of 15.7 µW at a temperature difference of 21.8 K. The flexible TEG showed excellent stability and durability even after 10,000 bending cycles. Finally, we demonstrate the shapeability of the CNT/BST foam by fabricating a concave TEG with conformal contact on the surface of a cylindrical glass tube, which suggests its practical applicability as a thermal sensor.

Strain engineering on metal-based catalysts has been utilized as an efficacious strategy to regulate the mechanism and pathways in various electrocatalytic reactions. However, controlling strain and establishing the strain-activity relationship still remain significant challenges. Herein, three different and continuous tensile strains (CuPd-1.90%, CuAu-3.37%, and CuAg-4.33%) are successfully induced by introducing heteroatoms with different atomic radius. The catalytic performances of CuPd-1.90%, CuAu-3.37%, and CuAg-4.33% display a positive correlation against tensile strains in electrochemical CO₂ reduction reaction (CO₂RR). Specifically, CuAg-4.33% exhibits superior catalytic performance with a 77.9% Faradaic efficiency of multi-carbon products at –300 mA cm^–2 current density, significantly higher than those of pristine Cu (Cu-0%). Theoretical calculations and in situ spectroscopies verify that tensile strain can affect the d-band center of Cu, thereby altering the binding energy of *CO intermediates and Gibbs free energies of the C–C coupling procedure. This work might highlight a new method for precisely regulating the lattice strain of metallic catalysts in different electrocatalytic reactions.

Layered vanadates are ideal energy storage materials due to their multielectron redox reactions and excellent cation storage capacity. However, their practical application still faces challenges, such as slow reaction kinetics and poor structural stability. In this study, we synthesized [Me₂NH₂]V₃O₇ (MNVO), a layered vanadate with expended layer spacing and enhanced pH resistance, using a one-step simple hydrothermal gram-scale method. Experimental analyses and density functional theory (DFT) calculations revealed supportive ionic and hydrogen bonding interactions between the thin-layered [Me₂NH₂]⁺ cation and [V₃O₇]^– anion layers, clarifying the energy storage mechanism of the H⁺/Zn²⁺ co-insertion. The synergistic effect of these bonds and oxygen vacancies increased the electronic conductivity and significantly reduced the diffusion energy barrier of the insertion ions, thereby improving the rate capability of the material. In an acidic electrolyte, aqueous zinc-ion batteries employing MNVO as the cathode exhibited a high specific capacity of 433 mAh g^–1 at 0.1 A g^–1. The prepared electrodes exhibited a maximum specific capacity of 237 mAh g^–1 at 5 A g^–1 and maintained a capacity retention of 83.5% after 10,000 cycles. This work introduces a novel approach for advancing layered cathodes, paving the way for their practical application in energy storage devices.