SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4505-9
Transition metal hydroxides are promising oxygen evolution reaction (OER) catalysts for alkaline water electrolysis. This study reports Ce-doped Co(OH)2 electrocatalysts synthesized via one-step electrodeposition, where the Ce3+/Ce4+ ratio is precisely controlled by deposition temperature. The optimized Ce-Co(OH)2 catalyst, obtained at 40°C, exhibits an overpotential of 236 mV at 10 mA cm-2 and maintains stability for 200 h. In an anion-exchange membrane water electrolyzer (AEMWE), the Ce-Co(OH)2 anode achieves a cell voltage of 2.04 V at 1 A cm-2 and operates for over 500 h at 500 mA cm-2. Mechanistic analysis reveals that Ce3+/Ce4+ dynamic electron buffering regulates surface reconstruction: during OER, electron transfer direction reverses (Ce → O → Co), with Ce donating electrons to Co sites to prevent over-oxidation and structural collapse. This work establishes a versatile strategy for balancing surface reconstruction and structural stability in Co-based OER catalysts, providing a foundation for designing high-performance, durable alkaline water oxidation electrocatalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4206-6
Precise patterning of highly ordered organic semiconductor (OSC) thin-film arrays is critical for next-generation electronics. We report a ladder-like polysilsesquioxane (LPSQ) strategy to synthesize two functional analogs with tunable surface energies and robust dielectric properties. These LPSQ dielectrics, functionalized with alkyl or fluoroalkyl side chains, serve dual roles as gate insulators and patterning layers to guide blade-coating of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT). This approach yields highly aligned arrays suitable for three-dimensional integration in flexible electronics. Synergistic combination of dense LPSQ dielectric packing and aligned semiconductor domains leads to excellent organic thin-film transistor (OTFT) performance, achieving approximately four-fold improvement in field-effect mobility compared to conventional silicon oxide dielectrics. Patterned LPSQ dielectrics enable high-resolution C8-BTBT patterning on plastic substrates, supporting 4-inch-scale 3D integration of flexible logic circuits, including inverters (voltage gain >100), NOR gates, and NAND gates. This work provides a scalable route to high-performance, large-area flexible organic circuits.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3983-4
Refrigeration is essential for modern society, supporting applications from household appliances and industrial manufacturing to microelectronics and biopharmaceutical cold chains. Conventional refrigeration technologies are constrained by environmental impact and low energy efficiency, emphasizing the importance of developing sustainable alternatives. Solid-state caloric refrigeration, particularly electrocaloric (EC) devices, offers a promising route owing to their high cooling efficiency, rapid electric-field-driven response, and potential for miniaturization. Significant progress has been achieved in various EC device configurations. However, EC devices still face challenges in achieving large temperature spans, high cooling power, and effective integration for specific applications. This review systematically summarizes these developments, focusing on device design and performance enhancement. It elucidates the fundamental and shared design strategies, classifies EC devices into fluid-based heat-transfer type, solid-based heat-transfer type, and thermal-resistance-modulated heat-switch architectures, and analyzes representative device structures, performance metrics, and application scenarios. Finally, energy-recovery strategies and future optimization directions toward more efficient EC systems are discussed. This work provides a comprehensive reference for the design innovation and practical implementation of EC-based solid-state refrigeration technologies.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3950-x
Photocatalytic oxygen reduction reaction (ORR) for hydrogen peroxide (H2O2) production via the two-electron pathway offers an environmentally friendly oxidant and a clean fuel. However, challenges exist in optimal oxygen (O2) adsorption capacities and maintaining O–O bond during O2 activation. Herein, we present a zinc single-atom catalyst (Zn/VN-CN) incorporating nitrogen vacancies (VN), designed to modulate the electronic structure of the photocatalyst, leading to optimized O2 adsorption energy and a remarkable enhancement in H2O2 yield. Benefiting from the synergistic effect between nitrogen vacancies and Zn single atoms, the optimized Zn/VN-CN catalyst exhibits a photocatalytic H2O2 production rate of 2.399 mmol g−1 h−1 under visible-light irradiation, representing a 12-fold enhancement compared to pristine g-C3N4 (CN), along with a high H2O2 selectivity of 87.4%. Combined experimental and theoretical studies indicate that the Zn-N3 sites act as highly active reaction centers, while nitrogen vacancies increase the charge density and downshift the d-band center of the Zn sites, thereby moderating O2 adsorption strength, lowering the activation energy barrier for the formation of *H2O2, and further converting it to H2O2. This work proposes an effective strategy for tuning O2 adsorption behavior to achieve highly selective and active photocatalytic H2O2 production.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202512031
The overuse of antibiotics has led to residual amoxicillin (AMX) in aquatic environments, promoting the spread of antibiotic resistance genes (ARGs) and threatening ecological safety. In this study, magnetic iron-modified biochar (Fe-BC) was prepared from agricultural waste sugarcane bagasse via FeCl3·6H2O impregnation and oxygen-limited pyrolysis. The adsorption performance and mechanism of Fe-BC for AMX were systematically investigated. Under conditions of 25 °C, pH 6, and initial AMX concentration of 50 mg·L−1, the adsorption capacity reached 32.61 mg·g−1. Characterization of Fe-BC before and after adsorption, combined with adsorption kinetics, isotherms, and thermodynamic analyses, revealed that adsorption primarily relied on oxygen-containing functional groups. The mechanisms included pore filling, electrostatic interaction, hydrogen bonding, complexation, and π–π interaction. After six thermal regeneration cycles, the removal efficiency of AMX remained above 76%. The specific surface area of Fe-BC increased from 279.20 m2·g−1 to 481.42 m2·g−1, an enhancement of approximately 72.4%. These results provide a technical reference for the resource utilization of agricultural waste and cost-effective treatment of antibiotic-containing wastewater in rural decentralized areas.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3999-x
The integration of photochromism (PhCh) and persistent luminescence (PersL) into a single material remains a formidable challenge due to the complex role of defects in modulating optical properties. Here, we employ structurally simple CsX (X = Cl, Br) nanocrystals (NCs) as a model system to elucidate the relationship between defects and optical behaviors. We demonstrate that CsX NCs accommodate two distinct types of chlorine vacancy defects upon X-ray irradiation: intrinsic vacancies from synthesis and X-ray-induced vacancies. This dual-defect engineering enables reversible blue coloration under X-ray irradiation (20–70 kV), attributed to recoverable chlorine vacancies that are rapidly eliminated by visible light within 30 s. The photochromic behavior exhibits excellent cycling stability with a color difference (ΔRL1) of 56.9% and a recovery rate (ΔRL2) of 98.1%. Furthermore, Br− incorporation deepens the energy level of intrinsic chlorine vacancies from 0.47–0.71 eV to 0.83 eV, resulting in intense persistent luminescence lasting over 30 minutes. These dual-mode PhCh–PersL characteristics position CsX NCs as promising candidates for X-ray colorimetric imaging and dynamic anti-counterfeiting applications. Our findings establish a defect-oriented design principle extendable to other halide systems, advancing the development of multifunctional photonic materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4047-0
The proliferation of electronic devices has exacerbated electromagnetic pollution, necessitating advanced electromagnetic wave (EMW) absorbing materials. In this study, VS2 nanorods were uniformly grafted onto graphene nanosheets (GNSs) via a facile ball milling method, constructing 1D/2D hierarchical VS2@GNSs composites with superior EMW absorption properties. The minimal reflection loss (RLmin) reached -49.83 dB at a thickness of 1.83 mm, while an ultra-broad effective absorption bandwidth (EAB) of 6.72 GHz was achieved at 1.96 mm. These performances are attributed to enhanced impedance matching and EMW attenuation capacities. Computer simulation technology (CST) full-wave simulations confirmed remarkable radar cross-section (RCS) suppression, with a reduction value of up to 20.38 dB m2 compared to a metallic substrate. This work provides theoretical and experimental guidance for designing high-performance stealth materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4088-y
Silicon nitride (Si3N4) is a strong, thermally stable covalent ceramic typically regarded as brittle with limited deformability. Recent experimental and density functional theory (DFT) studies indicate that the α/β interface undergoes a β→α transformation via sliding followed by bond-switching, suggesting a pathway to achieve plasticity, but DFT's spatiotemporal reach prevents a full mechanistic picture. Here, we develop a physics-informed high-accuracy neural network interatomic potential (NNAP) model with DFT-level accuracy for phase transformations and use it to perform large-scale atomistic simulations. NNAP-guided simulations show that structural relaxation during relative sliding between α- and β-phases at the interface triggers pronounced atomic-layer rearrangements and lowers the energy barrier by nearly 60%. We further find that the ensuing phase transformation does not proceed by isolated layer-by-layer switching but instead follows in-plane nucleation and growth mediated by a bilayer cooperative mechanism, which further reduces kinetic barriers and facilitates the transformation. CI-NEB calculations reveal that the bilayer cooperative pathway has an energy barrier of 0.018 eV/Ų, lower than the independent layer-by-layer manner (0.020 eV/Ų), indicating enhanced kinetic accessibility. These results provide new atomistic insights into interface-driven phase transformations in dual-phase Si3N4 and offer guidance for designing more deformable covalent ceramics.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3526-5
Polymer-based positive temperature coefficient (PTC) composites exhibit temperature-responsive resistivity, yet conventional systems with Curie temperatures (Tc) above 50 °C fail to meet the precision thermal management demands of room-temperature electronics. This study presents a ternary composite wherein carbon black (CB) is selectively localized within a myristyl alcohol (MA) phase, stabilized by an ethylene vinyl acetate (EVA) matrix. The reversible solid-liquid transition of MA dynamically disrupts and reconfigures CB conductive networks, while EVA elasticity suppresses phase migration at elevated temperatures. The optimized MA/EVA/CB composite achieves a low Tc of 35 °C, ultralow initial resistivity (ρin) of 50 Ω cm, high PTC intensity (PTCI = 7.0), and exceptional cycling stability with >95% resistivity retention after 100 thermal cycles. Even after 14 days of real space-environment exposure, the composite maintains ultralow resistivity and high PTCI. Differential scanning calorimetry and Fourier-transform infrared spectroscopy confirm molecular integrity under extreme conditions. Microstructural analysis reveals that MA melting/crystallization governs conductive network disruption and reconfiguration. A self-regulating heater fabricated from this composite stabilizes an aluminum block at 30.6 ± 0.03 °C under 20 V in a −10 °C environment without external control. These low-Tc PTC composites offer transformative potential for adaptive thermal management in aerospace electronics.