SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4420-7
Cu2-xSe is a leading p-type thermoelectric material owing to its phonon-liquid electron-crystal (PLEC) behavior, yet the atomic-scale mechanisms governing Cu+ migration remain unresolved. This study employs in situ high-resolution neutron diffraction coupled with maximum entropy method (MEM) analysis to map the temperature-dependent evolution of Cu+ nuclear density in β-Cu2Se and β-Cu1.95Se. At 398–423 K, intra-tetrahedral Cu 8c ↔ 32f <111> hopping emerges, with isosurface values of 0.505 fm Å-3 for β-Cu2Se and 0.484 fm Å-3 for β-Cu1.95Se. Above 448 K, inter-tetrahedral pathways form via Cu 32f ↔ 32f <100> or 32f ↔ 4b ↔ 32f <111> migration, as revealed by line scans along [1̅11̅] up to 723 K. The presence of Cu vacancies (x = 0.05) alters the onset and connectivity of these pathways, directly impacting phonon scattering and electron transport. These findings establish a structural basis for controlling Cu+ mobility, offering a rational route to mitigate Cu precipitation and enhance zT stability beyond 1.5 at 900 K. The work bridges microstructural dynamics and thermoelectric performance, providing critical guidance for defect engineering in superionic thermoelectrics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3803-8
The molecular copolymerization of donor-acceptor (D-A) interactions has been effectively utilized to modulate the charge transfer dynamics in polymeric carbon nitride (PCN) photocatalysts. Herein, a D-A configured photocatalyst (TPCN) was constructed by copolymerizing 4,4’,4’’-(1,3,5-triazine-2,4,6-triyl) trianiline (TAPT) as the electron donor with triazine units (electron acceptor). The unique propeller structure of TAPT, combined with the triazine framework, expanded the π-conjugated system and induced a strong built-in electric field (BIEF) across the D-A configuration. Theoretical calculations and transient absorption spectroscopy revealed that this synergistic effect facilitated intramolecular charge separation and widened the range of light absorption, indicating accelerated charge transfer and suppressed recombination in TPCN. The optimized TPCN3 sample exhibited dramatically enhanced photocatalytic H2O2 production (1.74 mmol g−1 h−1), representing a 13.4-fold increase over pristine PCN. Additionally, the TPCN3 sample also exhibited significantly faster degradation kinetics than PCN counterpart toward various emerging contaminants. This work demonstrates a promising strategy for designing efficient metal-free photocatalysts for sustainable H2O2 production and environmental remediation.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.3724/2097-213X.2025.JFCT.0025
Endogenous alkali and alkaline earth metals (AAEMs) in biomass ash and pyrolysis temperature significantly influence the properties of pyrolysis polygeneration products. This study selected potassium (K+) and calcium (Ca2+) as representative AAEMs, added them at mass ratios of 2%, 5%, and 7% to corn stover via impregnation, and conducted fixed-bed pyrolysis at 400, 500, and 600 °C to investigate the yields and compositions of gas, liquid, and solid products. Results showed that increasing metal ion concentration significantly increased biochar yield, with Ca2+ at 7% achieving 24.96% biochar yield, while bio-oil yield generally decreased. Ca2+ strongly promoted H2 formation due to its Lewis acidity, reaching 32.49% in gas at 7% concentration, and facilitated furan enrichment to 65.88%. K+ at low concentrations favored phenolic formation, while high concentrations promoted ketones and intensified bio-oil cracking. Increasing temperature from 400 to 600 °C decreased biochar yield and increased gas yield, with high temperatures enhancing secondary cracking and reforming, significantly raising H2 and CH4 yields while suppressing oxygenates. At 600 °C, K+ catalysis increased acids to 39.41%, while Ca2+ maintained furans at 65.89%. This study demonstrates that adjusting metal ion concentration and temperature enables directional regulation of high-value bio-oil components and high-energy gases, providing a theoretical basis for optimized biomass pyrolysis utilization.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606007
Cobalt-aluminum spinel metal oxides derived from hydrotalcite were synthesized via hydrothermal, coprecipitation, and sol-gel methods, and their catalytic performance for NO oxidation was systematically evaluated. Characterization by X-ray photoelectron spectroscopy (XPS), O2 temperature-programmed desorption (O2-TPD), H2 temperature-programmed reduction (H2-TPR), and Raman spectroscopy revealed that the synthesis method significantly influences the surface Co2+/Co3+ ratio, which in turn modulates the formation of surface oxygen vacancies. The hydrothermally synthesized catalyst (CoAlO-H) exhibited the highest density of surface oxygen vacancies, leading to enhanced adsorption and activation of gaseous oxygen and superior NO oxidation activity compared to coprecipitation (CoAlO-C) and sol-gel (CoAlO-S) counterparts. Mechanistic studies using NO-TPD, NO+O2-TPD, and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) identified nitrates as key intermediates. Notably, CoAlO-C and CoAlO-S followed the Langmuir-Hinshelwood (L-H) mechanism, whereas CoAlO-H operated via both L-H and Mars-van Krevelen (MvK) mechanisms. The exceptional performance of CoAlO-H is attributed to its abundant surface oxygen vacancies, high surface oxygen mobility, and low decomposition temperature of reaction intermediates. These findings provide a rational basis for designing efficient non-precious metal catalysts for NO oxidation in diesel exhaust aftertreatment.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3787-x
Circumventing the tumor's defensive antioxidant system and achieving precision cancer therapy remain major challenges in high-efficacy tumor treatments. Here, we propose a synergistic strategy integrating non-oxidative physical ablation and oxidative chemical intervention. An acid-responsive self-collapsing nanomineral PCSB is constructed, comprising poly(acrylic acid)-modified calcium sulfite (CaSO3) and a pH-responsive photoacoustic (PA) therapeutic molecule, aza-BDP. In the tumor acidic microenvironment, PCSB decomposes, releasing PA agents and SO2/Ca2+, thereby enabling combined non-oxidative mechanical damage from PA therapy and oxidative chemical damage from SO2 gas and Ca2+ ions. This dual-action approach effectively reduces resistance conferred by tumor antioxidant mechanisms and improves treatment precision. The study presents a synergistic physical-chemical strategy with significant potential for solid tumor elimination.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3951-4
Silicon anodes offer an ultrahigh theoretical capacity (4200 mAh g−1) but suffer from >300% volumetric expansion during cycling and unstable solid electrolyte interphase (SEI) formation, leading to rapid capacity fading. Here, we design a hierarchical composite p-cSi@aSi@MgSiN2@C featuring a porous crystalline-amorphous silicon core (p-cSi@aSi), an in-situ MgSiN2 transition layer, and an outer nitrogen-doped carbon shell. The 3D interconnected pores accommodate volume expansion, while amorphous silicon enables isotropic lithiation-induced strain, eliminating crystalline phase transition barriers. The MgSiN2 layer transforms into a tough Li3N-rich SEI with ultra-fast ion channels, and the carbon shell provides mechanical confinement and electronic conductivity. This synergistic interface engineering achieves an initial coulombic efficiency (ICE) of 81.4%, a charge transfer resistance of 16.4 Ω after 200 cycles (64% reduction), and a Li+ diffusion coefficient of 1.72×10−11 cm2 s−1. The anode delivers 1719.3 mAh g−1 at 0.2 C after 200 cycles and 823.8 mAh g−1 at 0.5 C after 500 cycles. The molten salt electrolysis synthesis achieves a current efficiency of 68.12% and specific energy consumption of 12.76 kWh kg−1, with an estimated electricity cost of 1154.69 USD ton−1, only 20% of commercial Si/C anodes. This work resolves the ICE-cycle life trade-off and provides a scalable, cost-effective approach for next-generation high-energy batteries.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4184-6
The industrial production of ε-caprolactam, the essential precursor for nylon-6, is a cornerstone of the modern polymer industry. Historically, this process evolved from energy-intensive non-catalytic routes to the more atom-economical ammoximation of cyclohexanone over titanosilicate catalysts using H2O2 as a green oxidant. Despite this progress, the reliance on concentrated H2O2 presents a significant sustainability bottleneck, as its commercial production via the anthraquinone process is energy-intensive, waste-prone, and involves hazardous transportation. A more sustainable ideal reaction involves the direct use of H2 and O2 to generate active oxygen species in situ. However, implementing this bifunctional route has long been thwarted by high noble metal loadings, poor H2 efficiency due to the rapid decomposition of intermediate H2O2, and the inherent instability of catalysts in the alkaline aqueous media required for ammoximation. In the January 2026 issue of Nature Catalysis, Wu and colleagues report a breakthrough by engineering a titanium-mordenite-confined, low-loaded Pd catalyst (0.055 wt% Pd@A-Ti-MOR-R) that achieves exceptional efficiency and industrial-grade longevity for direct ammoximation in water. The researchers proposed a “structured” solution to spatial confinement by utilizing an acid-treated Ti-MOR (A-Ti-MOR) featuring specific Ti-OH defect sites adjacent to silanol nests. These defects act as precise anchors to stabilize subnanometric Pd2 clusters, ensuring that the Pd and Ti active sites remain in “atomic proximity” within the 8-ring side pockets of the zeolite. This atomic-level configuration was rigorously verified using spherical-aberration-corrected annular dark field scanning transmission electron microscopy (ADF-STEM), which identifies bright contrasts from subnanometric Pd clusters with diameters below 0.5 nm near the framework pores. Furthermore, Pd K-edge extended X-ray-absorption fine-structure (EXAFS) analysis confirms the formation of Pd–O–Ti bridges through the identification of a specific scattering path at 3.67 Å, proving that the Pd clusters are chemically bonded to the framework Ti sites.