SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4202-3
Carbon dots (CDs) with absorption in the second near-infrared window (NIR-II, 900-1700 nm) hold promise for tumor theranostics, yet existing synthesis methods often involve complex procedures, harsh conditions, or lack precise control. Here we report a 'self-photooxidation-restructuring' strategy that enables structural reorganization of the carbon core in CDs, achieving a significant redshift of absorption into the NIR-II region. Under ultraviolet (UV) light irradiation, the precursor (B-CDs, absorption in UV region) generates singlet oxygen, which self-oxidizes aldehyde groups and the carbon skeleton of B-CDs to stronger electron-withdrawing carboxyl groups and carbon radicals, respectively. These processes facilitate the formation of new C=C bonds between isolated aromatic domains, thereby transforming B-CDs into novel CDs (N-CDs) characterized by enhanced donor-acceptor interactions and a redshift in absorption toward the NIR-II window. Various experimental data, including high-resolution XPS, FTIR, NMR, EPR, have proved the proposed formation mechanism. The novel N-CDs afforded a high photothermal conversion efficiency of up to 71.33%, which enabled 1064 nm laser-activated photoacoustic imaging (PAI)-guided photothermal therapy (PTT) in tumors. This work opens a new avenue for the synthesis and modulation of CDs in the NIR-II region.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4369-1
Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries for large-scale energy storage due to sodium's abundance and low cost. Among cathode materials, polyanionic compounds like Na3V2(PO4)2O2F (NVPOF) offer high energy density and dual voltage plateaus at ~3.6 and 4.0 V, but suffer from low electronic conductivity and sluggish Na+ diffusion. Here, we report a dual-modulation strategy combining high-valence Nb5+ doping and polydopamine-derived carbon coating to synthesize Na3V1.94Nb0.06(PO4)2O2F-C (NVPOF-Nb-C) via a hydrothermal route. X-ray diffraction and Rietveld refinement confirm that Nb5+ doping induces slight lattice expansion without altering the tetragonal I4/mmm framework. Density functional theory calculations reveal that Nb5+ doping optimizes the crystal structure and reduces the Na+ diffusion barrier, while the uniform carbon coating enhances electron transport. Consequently, NVPOF-Nb-C exhibits remarkably improved electrochemical performance, including high reversible capacity, excellent rate capability, and ultralong cycling stability. In a full cell with hard carbon anode, it delivers a high energy density of 487.2 Wh kg−1 at 1C and retains 91.51% capacity after 3000 cycles at 20C. This work provides a synergistic strategy to overcome the intrinsic limitations of polyanionic cathodes for practical SIB applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4220-x
High-temperature electronics demand non-volatile memories (NVMs) capable of stable operation above 500 °C for applications in space exploration, nuclear energy, and autonomous driving. Conventional silicon-based devices fail above ~250 °C, and silicon carbide (SiC) cannot process data above 300 °C. Memristors offer a promising solution due to their simple structure, low power consumption, and scalability. A recent breakthrough by Yang et al. (Science) demonstrated a graphene (Gra)/HfOx/W memristor achieving data retention at 700 °C, with retention time of 50 h, endurance of 10^9 cycles, ON/OFF ratio exceeding three orders of magnitude, and operation voltage ~1.5 V. The key innovation is replacing the Pt bottom electrode with in-situ grown graphene, which suppresses high-temperature diffusion of the W top electrode through the HfOx layer. In contrast, Pt/HfOx/W devices fail after annealing at 800 °C for 10^4 s due to W migration, forming conductive filaments that lock the device in the ON state. High-resolution TEM and EDS reveal tungsten oxide (WOx) formation at the W/HfOx interface in Pt-based devices, while Gra-based devices show no such degradation. STEM-EELS confirms W migration across the HfOx layer in Pt devices, but graphene acts as a diffusion barrier, preserving stable switching behavior. This interfacial engineering approach provides a viable pathway for high-temperature NVM, addressing the critical bottleneck of electrode diffusion.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3600-1
Two-dimensional planar pentagonal crystals, long pursued for their geometrically frustrated lattice configurations and emergent quantum phenomena, have remained challenging to realize due to the intrinsic incompatibility of regular pentagons with Euclidean tiling. Here, we unveil 37 dynamically stable binary planar pentagonal monolayers through high-throughput computational screening of 1470 stoichiometric candidates. These materials exhibit room-temperature magnetism, including ferromagnetic (Curie temperature up to 521 K), antiferromagnetic (Néel temperature up to 761 K), and altermagnetic (Néel temperature = 984 K) ground states, alongside unprecedented electronic states: Dirac semimetals, Dirac half-metal, nodal-loop semimetal, nodal-loop half-metal, and altermagnetic semiconductors (Mn4N2) with giant spin splitting (0.78 eV). The latter achieves pure spin-polarized transport windows (−0.04 to 0.36 eV) and strain-tunable valley splitting (18.2 meV under 4% uniaxial strain). Intrinsic type-II multiferroicity emerges in Fe4C2 and Mn4C2, featuring in-plane electric polarization (1.4 and 1.6 pC/m), ferroelasticity (0.8% and 1.2% reversible strain), and reversal chirality. Topological band analysis identifies chiral edge states in Dirac semimetal pentagons, alongside a magnetic topological insulator with Chern number |C| = 2 in Mo2S4 and W2Te4. Temperature-driven structural transitions in Os2S4 and Tc2S4 from pentagonal to Lieb lattices accompany topological state switching and metal-to-semiconductor transitions. This work establishes pentagonal lattices as a platform for symmetry-driven multifunctionality, bridging geometric frustration with applications in spintronics, nanoelectronics, and quantum devices.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3746-x
The polyanionic compound Na3V2(PO4)2O2F (NVPOF) possesses a stable three-dimensional framework, high theoretical specific capacity, and favorable operating voltage, yet its sluggish Na+ diffusion kinetics and low electronic conductivity impede industrial application. This study proposes a dual regulation strategy combining carbon coating and heat treatment temperature to synergistically enhance crystallinity and electrochemical performance. NVPOF@C-400 and NVPOF@C-600 were synthesized via in-situ dopamine hydrochloride coating followed by heat treatment at 400 °C and 600 °C, respectively. Carbon coating at 600 °C significantly improved crystallinity and increased electronic conductivity by three orders of magnitude through the carbon layer's conductive network. The ~4.5 nm carbon layer effectively suppressed abnormal grain growth and secondary crystallization aggregation at high temperatures, maintaining uniform particle size of approximately 0.36 μm, which shortens Na+ diffusion pathways and prevents ion transport obstruction. Consequently, NVPOF@C-600 delivered a high discharge capacity of 102.5 mAh g−1 at 20 C and retained 96.5% capacity after 10,000 cycles. In a full-cell configuration with hard carbon (HC), NVPOF@C-600//HC achieved an impressive 89.3% capacity retention after 9,000 cycles. This work provides critical insights for practical implementation of high-performance NVPOF cathodes in sodium-ion batteries.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3887-6
The proliferation of 5G/6G communications and radar systems has intensified electromagnetic wave (EMW) leakage, interference, and thermal management challenges. This study presents a 3D MXene sponge/NiFe@NC heterostructure with tunable pore architecture, fabricated by pyrolyzing a polyurethane (PU) foam template uniformly coated with NiFe-decorated Ti3C2Tx MXene nanosheets. The resulting porous dielectric-magnetic network integrates interconnected MXene pathways with uniformly dispersed NiFe@NC nanoparticles, enabling synergistic dielectric-magnetic loss via conduction loss, dipole/interface polarization, and magnetic loss. Precise pore structure design enhances impedance matching and promotes multi-scattering and internal reflection of EMWs. An 'EMW-pore matching' mechanism is proposed, where pore size governs impedance matching at specific frequencies, enabling tunable absorption performance. The optimized absorber achieves a reflection loss (RL) of -67.84 dB, while radar cross-section (RCS) simulations confirm exceptional attenuation and stealth potential. Additionally, the 3D skeleton derived from PU foam confers remarkable thermal resistance and flame retardancy. This pore-regulation strategy provides a scalable route to designing lightweight, broadband, and thermally stable EMW absorbers for next-generation communication and stealth applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3595-7
Cu(I) complexes exhibiting thermally activated delayed fluorescence (TADF) have emerged as promising alternatives to noble-metal-based emitters for organic light-emitting diodes (OLEDs). However, the development of red-emitting Cu(I) complexes has been hindered by slow radiative decay and fast nonradiative decay. In this study, a linear two-coordinate Cu(I) complex, ICuTMC, was designed and synthesized. By pairing a pyrazine-fused N-heterocyclic carbene and a tetra-methylcarbazolyl ligand, a strong ligand-to-ligand charge transfer excited state is generated. Single-crystal structure authenticates close intramolecular C–H···Cu contacts, providing good steric shielding to the metal center. C–H···π interactions between ligands are also revealed. The complex exhibits highly efficient red TADF with emission maximum at 622 nm, photoluminescence quantum yield of 76%, and short delayed fluorescence lifetime of 0.24 μs. This is enabled by a large oscillator strength from the coplanar donor-Cu-acceptor conformation, a small singlet-triplet energy gap from spatial separation of frontier molecular orbitals, and strong spin-orbit coupling from the metal center. Vacuum-deposited OLEDs based on ICuTMC achieve a peak external quantum efficiency of 25.9% and a significantly small roll-off of 1.9% at 10,000 cd m−2. These performances demonstrate a way to overcome the energy gap law for linear coinage metal complexes toward red OLEDs.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.3724/2097-213X.2025.JFCT.0032
This study elucidates the nonlinear relationship between the softening point of coating asphalt and its oxidative cross-linking behavior, as well as the sodium storage performance of the derived hard carbon. Comparative analysis of asphalts with low (80 °C), medium (160 °C), and high (260 °C) softening points revealed that both the 80 and 260 °C asphalts incorporated a higher oxygen content (20%–25%) during oxidation, leading to the formation of a deeply cross-linked structure dominated by anhydride and ester groups. This effectively suppressed graphitization during carbonization, yielding hard carbon with large interlayer spacing, high disorder, and abundant closed pores. The derived hard carbon exhibited superior sodium storage performance: the initial charge capacities of EPOC-80 and EPOC-260 reached 314.7 and 306.6 mA·h/g, with first-cycle coulombic efficiencies of 81.3% and 79.3%, respectively, along with excellent cycling stability and rate capability. In contrast, the medium softening point asphalt (160 °C) showed limited oxygen incorporation (~5%) and insufficient cross-linking after oxidation, resulting in a densely packed hard carbon with smaller interlayer spacing (3.46 Å) and restricted sodium storage sites, which led to a significantly reduced capacity of 173.2 mA·h/g. This work provides new design principles and theoretical support for optimizing hard carbon anode structures through precise control of the precursor softening point.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607006
This study evaluates the global warming potential (GWP) of three typical air pollution control device (APCD) configurations in municipal solid waste (MSW) incineration under ultra-low emission standards. The configurations are APCD1 (SNCR+SDS+DS+ACI+FF), APCD2 (SNCR+SDS+DS+ACI+FF+SCR+WS), and APCD3 (SNCR+SDS+DS+ACI+FF+WS+SCR). Life cycle assessment (LCA) was applied to quantify GWP. Results indicate that APCD3 exhibits the highest GWP due to increased electricity consumption, yet it achieves the lowest pollutant emissions among the three. APCD1 shows the highest NOx emissions, contributing significantly to GWP, and requires technological upgrades. APCD2 consumes more resources but does not proportionally reduce emissions, suggesting inefficiencies. Electricity consumption is the dominant factor influencing GWP across all processes; reducing electricity use and improving energy efficiency are critical for mitigating environmental impact. The study recommends further research on CO2 reduction strategies and adoption of more efficient DeNOx technologies to align MSW incineration with ultra-low emission and low-carbon goals.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3499-6
Biomass-derived hard carbons (HCs) are promising anodes for sodium-ion batteries (SIBs) due to their low cost, renewable nature, and structural stability, yet their practical application is hindered by a low initial Coulombic efficiency (ICE) and inadequate rate capability. Herein, we report a tri-functional nitric acid treatment coupled with one-step carbonization to synthesize a hard carbon with a sp2-C-dominated structure. The process not only eliminates impurities but also selectively dissolves lignin in the biomass, thereby promoting the alignment of graphite microcrystals. At the same time, edge-N and C=O groups are grafted onto the carbon skeleton, which together produce an HC with an optimized interlayer spacing and abundant closed micropores. These structure modifications collectively increase Na+ adsorption kinetics in the sloping region and enable efficient sodium storage in the low-voltage plateau region, yielding a high ICE of 91.69% and a remarkable rate capability, with 83.9% capacity retention at 600 mA g−1. A full SIB cell using this HC anode with a Na3V2(PO4)3 cathode delivers an energy density of 213.14 Wh kg−1, demonstrating its practical potential. This work offers a simple and scalable engineering strategy to overcome the performance vs. manufacturing cost dilemma in developing HC anodes.