Large-scale green hydrogen production technology, based on the electrolysis of water powered by renewable energy, relies heavily on non-precious metal oxygen evolution reactions (OER) electrocatalysts with high activity and stability under industrial conditions (6 M KOH, 60°C–80°C) at large current density. Here, we construct Fe and Co co-incorporated nickel (oxy) hydroxide (Fe_2.5Co_2.5Ni₁₀O_yH_z@NFF) via a multi-metal electrodeposition, which exhibits outstanding OER performance (overpotential: 185 mV @ 10 mA cm⁻²). Importantly, an overwhelming stability for more than 1100 h at 500 mA cm⁻² under industrial conditions is achieved. Our combined experimental and computational investigation reveals the surface-reconstructed γ-NiOOH with a high valence state is the active layer, where the optimal (Fe, Co) co-incorporation tunes its electronic structure, changes the potential determining step, and reduces the energy barrier, leading to ultrahigh activity and stability. Our findings demonstrate a facile way to achieve an electrocatalyst with high performance for the industrial production of green hydrogen.

Anionic redox reaction (ARR) can provide extra capacity beyond transition metal (TM) redox in lithium-rich TM oxide cathodes. Practical ARR application is much hindered by the structure instability, particularly at the surface. Oxygen release has been widely accepted as the ringleader of surficial structure instability. However, the role of TM in surface stability has been much overlooked, not to mention its interplay with oxygen release. Herein, TM dissolution and oxygen release are comparatively investigated in Li_1.2Ni_0.2Mn_0.6O₂. Ni is verified to detach from the lattice counter-intuitively despite the overwhelming stoichiometry of Mn, facilitating subsequent oxygen release of the ARR process. Intriguingly, surface reorganization occurs following regulated Ni dissolution, enabling the stabilization of the surface and elimination of oxygen release in turn. Accordingly, a novel optimization strategy is proposed by adding a relaxation step at 4.50 V within the first cycle procedure. Battery performance can be effectively improved, with voltage decay suppressed from 3.44 mV/cycle to 1.60 mV/cycle, and cycle stability improved from 66.77% to 90.01% after 100 cycles. This work provides new perspectives for clarifying ARR surface instability and guidance for optimizing ARR performance.

There is an urgent need to develop high-areal-capacity silicon (Si) anodes with good cycling stability and rate capability for high-energy-density lithium-ion batteries (LIBs). However, this remains a huge challenge due to large volume expansion-induced mechanical degradation and electrical connectivity loss in thick electrodes. Here, a three-in-one strategy is proposed to achieve high-areal-capacity silicon anodes by constructing a multi-level interconnected 3D porous and robust conductive network that carbon nanofibers and vertical carbon nanosheets tightly encapsulate on the surface of Si nanoparticles (Si NPs) anchored in porous carbon felts. This network accommodates large volume expansion of Si NPs to significantly improve electrode mechanical stability and creates excellent electrical connectivity to boost charge transport in thick electrodes, revealed through Multiphysics field simulations and in situ electrochemical techniques. Therefore, the designed Si anodes achieve superior long-term stability with a capacity of 8.13 mAh cm⁻² after 500 cycles and an ultrahigh areal capacity of 45.8 mAh cm⁻². In particular, Ah-level pouch cells demonstrate an impressive capacity retention of 79.34% after 500 cycles at 1 C. Our study offers novel insights and directions for understanding and optimizing high-areal-capacity silicon–carbon composite anodes.

The realization of practical solar hydrogen production relies on the development of efficient devices with nontoxic and low-cost materials. Since the predominant contributors for the performance and cost are the catalyst and the light absorber, it is imperative to develop cost-effective catalysts and absorbers that are compatible with each other for achieving high performance. In this study, a 10% efficient solar-to-hydrogen conversion device was developed through the meticulous integration of low-cost Ni Heazlewoodite-based catalysts for the hydrogen evolution reaction (HER) and ternary bulk heterojunction organic semiconductor (OS)-based light absorbers. Se-incorporated Ni₃S₂ was synthesized using a simple one-step hydrothermal method, which demonstrated a low overpotential and Tafel slope, indicating superior HER activity compared to Ni₃S₂. The theoretical calculation results validate the enhanced HER performance of the Se-incorporated Ni₃S₂ catalyst in alkaline electrolytes. The ternary phase organic light absorber is designed to generate tailored photovoltage and maximized photocurrent, resulting in a photocurrent density of 8.24 mA cm⁻² under unbiased conditions, which corresponds to 10% solar to hydrogen conversion. Low-temperature photoluminescence spectroscopy results revealed that the enhanced photocurrent density originates from a reduction in both phonon- and vibration-induced inter- and intramolecular non-radiative decay. Our results establish a new benchmark for the emerging OS-based efficient solar hydrogen production based on nontoxic and cost-effective materials.

Efficient photocatalytic water splitting can be significantly enhanced through the careful design of S-scheme heterostructures, which play a pivotal role in optimizing performance. Herein, we report the construction of ZnIn₂S₄/CdS S-scheme heterojunctions under ambient conditions, based on a sonochemical strategy. This structure is facilitated by the well-matched interface between the (007) plane of layered ZnIn₂S₄ and the (101) plane of CdS, leading to a threshold optical response of 2.12 eV, which optimally aligns with visible light absorption. As a proof of concept, the resulting ZnIn₂S₄/CdS catalysts demonstrate a remarkable improvement in photocatalytic H₂ evolution, achieving a rate of 5678.2 μmol h⁻¹g⁻¹ under visible light irradiation (λ > 400 nm). This rate is approximately 10 times higher than that of pristine ZnIn₂S₄ nanosheets (NSs) and about 4.6 times higher than that of CdS nanoparticles (NPs), surpassing the performance of most ZnIn₂S₄-based photocatalysts reported to date. Moreover, they deliver a robust photocatalytic performance during long-term operation of up to 60 h, showing their potential for use in practical applications. Based on the theoretical calculation and experimental results, it is verified that the movements of electrons and holes in the opposite direction could be induced by the disparity in the work function and the internal electric field within the interfaces, thus facilitating the construction of S-scheme heterojunctions, which fundamentally suppresses carrier recombination while minimizing photocorrosion of ZnIn₂S₄ toward enhanced photocatalytic behaviors.

Despite the rapid efficiency increase, tin halide perovskite solar cells are significantly behind their lead-based counterpart, with the highest reported efficiency of 15.38%. The main reason for this large difference is attributed to the instability of Sn²⁺, which easily oxidizes to Sn⁴⁺, creating Sn vacancies and increasing the open-circuit voltage loss. In this work, we implemented tin thiocyanate (Sn(SCN)₂) as an additive for passivating the bulk defects of a germanium-doped tin halide perovskite film. Adding Sn²⁺ and SCN⁻ ions reduces the Sn and iodine vacancies, limiting non-radiative recombination and favoring longer charge-carrier dynamics. Moreover, the addition of Sn(SCN)₂ induces a higher film crystallinity and preferential orientation of the (l00) planes parallel to the substrate. The passivated devices showed improved photovoltaic parameters with the best open-circuit voltage of 0.716 V and the best efficiency of 12.22%, compared to 0.647 V and 10.2% for the reference device. In addition, the passivated solar cell retains 88.7% of its initial efficiency after 80 min of illumination under 100 mW cm^-2 and is substantially better than the control device, which reaches 82.6% of its initial power conversion efficiency only after 30 min. This work demonstrates the passivation potential of tin-based additives, which combined with different counterions give a relatively large space of choices for passivation of Sn-based perovskites.

The strategic design and synthesis of photothermal/photocatalytic materials are pivotal to realizing photothermal conversion water evaporation coupled with photocatalytic sewage purification functions. In this work, based on the principle of three primary colors, brick-red g-C₃N₄/Ag₂CrO₄ composite was loaded onto a green polyurethane (PU) sponge using polyvinyl alcohol (PVA) as the linking agent. The resultant PU/PVA/g-C₃N₄/Ag₂CrO₄ composite exhibits outstanding performance in simultaneous photothermal/photocatalytic water evaporation, pollutant degradation, sterilization, and thermoelectric generation. Under 1.0 kW m⁻² irradiation, the water evaporation rate reaches 3.19 kg m⁻² h⁻¹, while a single thermoelectric module generates a maximum thermoelectric output power of 0.25 W m⁻². Concurrently, rhodamine B (RhB) at a concentration of 4.0 × 10⁻⁴ mol L⁻¹ undergoes complete photocatalytic degradation within 40 min. When the light intensity is 2.0 kW m⁻², the evaporation rate soars to 8.52 kg m⁻² h⁻¹, and the thermoelectric power output increases to 1.1 W m⁻². Furthermore, this photothermal/photocatalytic material based on the principle of three primary colors has excellent photothermal/photocatalytic antibacterial activity against Escherichia coli. By abandoning black light-absorbing materials, more active sites of the photocatalyst can be exposed. The g-C₃N₄/Ag₂CrO₄ heterojunction accelerates the separation of photogenerated carriers, while the hydrophilic groups in the photothermal/photocatalytic materials reduce the water evaporation enthalpy. This research provides a novel approach for fabricating multi-function photothermal/photocatalytic materials, which could quicken the development of solution to freshwater and electricity energy shortages as well as environmental pollution issues.

Hard carbons are promising anode materials for sodium-ion batteries (SIBs), but they face challenges in balancing rate capability, specific capacity, and initial Coulombic efficiency (ICE). Direct pyrolysis of the precursor often fails to create a suitable structure for sodium-ion storage. Molecular-level control of graphitization with open channels for Na⁺ ions is crucial for high-performance hard carbon, whereas closed pores play a key role in improving the low-voltage (< 0.1 V) plateau capacity of hard carbon anodes for SIBs. However, creation of these closed pores presents significant challenges. This work proposes a zinc gluconate-assisted catalytic carbonization strategy to regulate graphitization and create numerous nanopores simultaneously. As the temperature increases, trace amounts of zinc remain as single atoms in the hard carbon, featuring a uniform coordination structure. This mitigates the risk of electrochemically irreversible sites and enhances sodium-ion transport rates. The resulting hard carbon shows an excellent reversible capacity of 348.5 mAh g⁻¹ at 30 mA g⁻¹ and a high ICE of 92.84%. Furthermore, a sodium storage mechanism involving “adsorption–intercalation–pore filling” is elucidated, providing insights into the pore structure and dynamic pore-filling process.

The urgent demand for renewable energy solutions, propelled by the global energy crisis and environmental concerns, has spurred the creation of innovative materials for solar thermal storage. Photothermal phase change materials (PTPCMs) represent a novel type of composite phase change material (PCM) aimed at improving thermal storage efficiency by incorporating photothermal materials into traditional PCMs and encapsulating them within porous structures. Various porous encapsulation materials have been studied, including porous carbon, expanded graphite, and ceramics, but issues like brittleness hinder their practical use. To overcome these limitations, flexible PTPCMs using organic porous polymers—like foams, hydrogels, and porous wood—have emerged, offering high porosity and lightweight characteristics. This review examines recent advancements in the preparation of PTPCMs based on porous polymer supports through techniques like impregnation and in situ polymerization, assessing the impact of different porous polymer materials on PCM performance and clarifying the mechanisms of photothermal conversion and heat storage. Subsequently, the most recent advancements in the applications of porous polymer-based PTPCMs are systematically summarized, and future research challenges and possible solutions are discussed. This review aims to foster awareness about the potential of PTPCMs in promoting environmentally friendly energy practices and catalyzing further research in this promising field.

Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries. Therefore, nitrogen-doped carbon-capped triphasic heterostructure Cu₃P/Co₂P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization. Kinetic analyses (cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic intermittent titration technique) and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode. Based on this, Cu₃P/Co₂P/CoP@NC demonstrated excellent rate performance (305.9 mAh g⁻¹ at 0.3 A g⁻¹ and 202.8 mAh g⁻¹ even at 10 A g⁻¹) and cycling stability (the capacity decay rate is only 0.12% from the 5th to 300th cycle) when it is used for sodium-ion battery anodes. The in situ X-ray diffraction, ex situ X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy tests showed that Cu₃P/Co₂P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage. In addition, the NVP@reduced graphene oxide (rGO)//Cu₃P/Co₂P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g⁻¹ after 50 cycles at 0.3 A g⁻¹. This work can provide a reference for the design of high-performance sodium electrode anode materials.

The search for photoactive materials that are able to efficiently produce solar fuels is a growing research field to tackle the current energy crisis. Herein, we have prepared two ionic non-noble metallo-supramolecular polymers Se-MTpy (M = Co or Ni), and constructed their composites with single-walled carbon nanotubes (CNTs) via electrostatic attraction and π–π interactions for efficient and stable photocatalytic hydrogen evolution. In the photocatalytic system, the cationic Se-MTpy as host and anionic CNTs as guest are assembled into a binary composite, which exhibits superior photocatalytic activity under visible light irradiation (> 420 nm). The optimized CNT@Se-CoTpy composite, containing 1.2 wt% metal loading, achieves 7 times higher hydrogen evolution rate (2.47 mmol g⁻¹ h⁻¹) than bare Se-CoTpy (0.35 mmol g⁻¹ h⁻¹). This is attributed to the constructive formation of junctions between polymer and CNTs, facilitating interfacial charge transfer and transport for efficient proton reduction. The composite system also shows high photostability after continuous irradiation for ~30 h. The combination of experimental and theoretical analysis demonstrates the higher activity for reducing H₂O to H₂ of Se-CoTpy than Se-NiTpy. The feasible interfacial architecture proposed in this study represents an effective approach to achieve high photocatalytic performance.

Metallene has been widely considered as an advanced electrocatalytic material due to its large specific surface area and highly active reaction sites. Herein, we design and synthesize ultrathin rhodium metallene (Rh ML) with abundant wrinkles to supply surface-strained Rh sites for driving acetonitrile electroreduction to ethylamine (AER). The electrochemical tests indicate that Rh ML shows an ethylamine yield rate of 137.1 mmol g_cat⁻¹ h⁻¹ in an acidic solution, with stability lasting up to 200 h. Theoretical calculations reveal that Rh ML with wrinkle-induced compressive strain not only shows a lower energy barrier in the rate-determining step but also facilitates the ethylamine desorption process compared to wrinkle-free Rh ML and commercial Rh black. The assembled electrolyzer with bifunctional Rh ML shows an electrolysis voltage of 0.41 V at 10 mA cm⁻², enabling simultaneous ethylamine production and hydrazine waste treatment. Furthermore, the voltage of an assembled hybrid zinc–acetonitrile battery can effectively drive this electrolyzer to achieve the dual AER process. This study provides guidance for improving the catalytic efficiency of surface atoms in two-dimensional materials, as well as the electrochemical synthesis technology for series-connected battery–electrolyzer systems.