Hua-Jun Qiu

Solar-driven interfacial evaporation has emerged as a promising strategy for sustainable freshwater production. However, simultaneously achieving efficient photothermal conversion and optimized water transport within a single material system remains challenging. Herein, three-dimensional (3D) nitrogen-doped nanoporous graphene (NG) with tunable microstructures is synthesized by tuning the composition of Ni-based nanoporous templates via chemical vapor deposition (CVD). The defect density of the CVD-grown NG clearly increases with the number of components (or entropy) of the nanoporous alloys, reducing thermal conductivity, and promoting heat localization. Furthermore, when Mo element is included in the nanoporous alloy template (np-MnNiCoFeMo), MoC forms during CVD, inducing secondary nanoholes on the graphene tube walls and creating more defects. By selectively removing the alloy template, the obtained nanoporous graphene/MoC composite (5-NG@MoC) exhibits synergistically enhanced photothermal conversion due to the combined light absorption from both components of the composite. Consequently, 5-NG@MoC achieves a broadband solar absorption of 94% (250–2500 nm) and delivers an evaporation rate of 1.76 kg·m–2·h–1 with a photothermal conversion efficiency of 92.8% under one-sun irradiation. The free-standing and ultralight composite also demonstrates excellent stability and salt resistance during seawater desalination. This work provides an effective strategy for engineering graphene-based photothermal materials toward high-efficiency water evaporation.

Ruthenium dioxide (RuO ₂ ) is widely considered as a leading non‐iridium candidate for the acidic oxygen evolution reaction (OER) in proton exchange membrane water electrolysis (PEMWE), owing to its high intrinsic activity and comparatively low cost. Its practical implementation, however, is fundamentally limited by a persistent activity–stability trade‐off arising from the close coupling between oxygen evolution, lattice oxidation, and Ru dissolution under strongly acidic and oxidizing conditions. This review summarizes recent progress in RuO ₂ ‐based acidic OER catalysts from a mechanism‐centered perspective, with emphasis on how electronic structure, defect chemistry, lattice oxygen reactivity, and spin‐related effects collectively govern catalytic activity, reaction pathways, and degradation behavior. We further discuss how operando characterization has advanced understanding of dynamic active states and stability limits and highlight the emerging role of high‐throughput computation, machine learning, and active learning in accelerating catalyst discovery. By integrating mechanistic understanding, materials engineering, and data‐driven design, this review aims to outline a coherent framework for the development of highly active, durable, and scalable RuO ₂ ‐based catalysts for acidic water oxidation.

This study aims to transform the traditional polypropylene (PP) separator from a passive physical barrier into a “functional interfacial layer” to guide lithium deposition. A free-standing nitrogen-doped nanoporous nanotubular graphene (NG) network-based thin film is used to modify the separator (PP@NG) in a binder-free manner. Its open nanoporous/tubular structure and nitrogen-dopants endow the film with excellent electrolyte wettability and electrical/thermal conductivity. Moreover, the nanoporous channel guides the uniform Li+ flux through the film and subsequent deposition. Accordingly, the PP@NG can reduce the lithium nucleation overpotential from 38.0 to 17.7 mV and increase the tLi+ to 0.62. The symmetric Li|PP@NG|Li achieves a better rate performance and stable cycling for 800 h. The Li|PP@NG|LiNi0.8Co0.1Mn0.1O2 full cell shows a capacity retention of 64.8% after 900 cycles at 1.0 C. Even combined with a high cathode mass loading of 6.1 mAh·cm–2 or near 5.0 V high-voltage cathode, clearly enhanced performance can still be achieved.

High‐entropy oxides (HEOs) are promising electrocatalysts for the sluggish oxygen evolution reaction (OER). The lattice oxygen mechanism (LOM) offers a lower thermodynamic barrier than the conventional adsorbate evolution mechanism (AEM). However, maintaining structural integrity while activating lattice oxygen during prolonged electrolysis remains a significant challenge. Herein, we report a dual sacrificial template strategy to synthesize single‐crystalline porous hollow high‐entropy ZnVCrMoMn spinel oxides (ZnVCrMoMn‐HHESOs). Chemical probe, in situ spectroscopic, and isotope‐labeling experiments demonstrate that multicomponent electronic interactions synergistically enhance lattice oxygen activation and promote a dominant LOM pathway with high structural stability. Density functional theory calculations reveal that high‐valent cation incorporation induces electron redistribution, upshifts the O 2p‐band center toward the Fermi level, and strengthens metal–oxygen covalency, facilitating lattice oxygen participation in the OER. Consequently, ZnVCrMoMn‐HHESOs delivers an ultralow overpotential of 218 mV at 10 mA·cm ⁻² and outstanding stability over 400 h. In a lab‐scale electrolyzer, it achieves 774 mA·cm ⁻² at 1.7 V and operates stably at 500 mA·cm ⁻² for over 500 h with a voltage degradation rate of merely 0.07 mV·h ⁻¹ . This work demonstrates the rational design of hollow high‐entropy spinel oxides as an effective strategy for developing highly active and stable LOM‐based OER electrocatalysts.

Dendrite-free Zn anodes enabling stable cycling at high current densities and capacities remain a critical challenge for zinc-based energy storage. Here, we report a 3D free-standing nanotubular nanoporous N-doped graphene (np-NG) network doped with ultrathin Bi₂O₃ sheets (np-NG/Bi) as ultrahigh-capacity anode host. The lightweight, binder- and current-collector-free host enables uniform, rapid Zn deposition with near-complete volume utilization. Owing to its mechanical robustness, high conductivity, and large surface area, free-standing np-NG/Bi sustains stable cycling for 4000 h at 5 mA cm^–2 (5 mAh cm^–2) and over 600 h at 50 mA cm^–2 (10 mAh cm^–2). The high rate performance is attributed to the highly curved graphene nanotubular architecture and curvature-induced zincophilicity surfaces, which enable a rapid, tube interior-first, and dendrite-free Zn²⁺ deposition. The superior performance of np-NG/Bi is further demonstrated in Zn-ion and Zn–air batteries, highlighting a 3D graphene design strategy for high-performance Zn metal anodes in next-generation energy systems.

The high-yield synthesis of uniform Cu/Ru nanostructures is crucial for catalyzing nitrate (NO₃^-) reduction to ammonia (NH₃), yet it remains highly challenging. Herein, we report a facile strategy for synthesizing Cu/Ru bimetallic nanocages in high yield, driven by the Kirkendall effect. This process induces nonequilibrium atomic interdiffusion at the Cu/Ru interface, generating a net outward flux of Cu atoms and a counter-flux of vacancies, which collectively lead to the formation of a uniform nanocage structure. Importantly, the Cu₈₇Ru₁₃ nanocages exhibit superior performance in the electrochemical NO₃^- reduction reaction (NO₃^-RR), achieving a maximal Faradaic efficiency (FE) of 91% and an NH₃ production rate of 3353 mmol h^-1 g^-1 at -0.3 V (vs reversible hydrogen electrode (RHE)). In situ characterization reveals that within Cu/Ru nanocages, Cu sites adsorb NO₃^- and reduce it to *NO₂, while Ru sites reduce adsorbed *H, which protonates reaction intermediates to facilitate the conversion of NO₃^- to NH₃.

As promising sodium ion battery (SIB) anodes, transition metal sulfide (TMS)-based heterojunctions still suffer from sluggish kinetics, low capacity, and structural instability. Herein, we design a nanoporous structured senary (AlCrCo)NiFeS₂/MnS high-entropy heterojunction using dealloyed senary oxide as the starting materials. Owing to the high-entropy engineering-induced electronic structure regulation, the built-in electric field, the 3D nanoporous structure, and a hard carbon coating, the senary heterojunction exhibits a record high capacity of 885.5 mAh g^-1 after 110 cycles at 0.1 A g^-1. Even at 40.0 A g^-1, a high capacity of 331.5 mAh g^-1 can be achieved after 4000 cycles. DFT calculations reveal the modified electronic structure (denser energy band structure) induced by multiple-metal ion mixing, which enhances the electronic conductivity and sodium ion adsorption when compared with those of the ternary NiFeS₂/MnS heterojunction. This work highlights the potential of high-entropy engineering for developing SIB anodes with one of the best overall performances.

We report a bimodal nanoporous Cu/Cu₂O doped with bismuth (np-Cu/Cu₂O (Bi)) by dealloying an Al-Cu-Bi-based two-phase precursor alloy. Different from the typically used unimodal porous Cu, the bimodal structure provides big pores (hundreds of nanometers) for enough Zn deposition (high capacity) and small pores (10 nm) with a high specific surface area for high rates. Moreover, the formation of the Cu₂O surface with Bi doping significantly reduces the Zn deposition overpotential. The np-Cu/Cu₂O (Bi)-based half cells and symmetric cells exhibit much lower Zn deposition overpotential (88.7 mV) and excellent cycling stability (over 260 h), respectively, even at a large current density of 50 mA cm^-2, obviously outperforming the pure Zn-based cells and most reported results. The dendrite issue and side reaction are also largely limited by the bimodal nanoporous structure design and surface modification. This work provides inspiration for developing an advanced Zn anode through porosity design and surface chemistry modulation.

Transition metal sulfides are promising sodium‐ion battery anodes. Herein, a multicomponent MnNiFe‐based sulfide heterojunction with ultrafine nanoporous structure and inherent 3D carbon coating is synthesized using commercially available MnNiFeCO ₃ as the precursor. It is found that the multicomponent metal interaction greatly inhibits the surface diffusion during carbonate decomposition process, resulting in ultrafine nanoporous MnNi(Fe)O ₃ (≤ 10 nm) with a much larger surface area when compared with a single metal‐based counterpart. To enhance the conductivity and structure stability of the heterojunction, a thin layer of N, S‐doped 3D porous carbon is inherently coated on the nanoporous MnNiFeS _x (NS‐C@MnNiFeS) by first forming a 3D polyaniline layer on the nanoporous MnNi(Fe)O ₃ , which is then transformed into doped carbon during the vulcanization process. Owing to the multicomponent heterojunction design (which may provide more active sites for effective Na ⁺ adsorption), much increased specific surface area, and 3D inherent carbon coating, the NS‐C@MnNiFeS exhibits significantly enhanced performance for Na ⁺ storage. After 90 cycles at 0.1 A g ⁻¹ , a record‐high reversible capacity of 859.2 mAh g ⁻¹ is achieved, and it can be stably cycled for 1500 cycles at a current density of 10.0 A g ⁻¹ . DFT calculation reveals the modified electronic structure and enhanced Na ⁺ adsorption by constructing the heterojunction.