SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4238-2
Infrared nonlinear optical (IR NLO) materials are critical for laser frequency conversion, yet their performance is often constrained by a trade-off between second harmonic generation (SHG) efficiency and laser-induced damage threshold (LIDT). Here, we report a new ternary diamond-like compound, AlGaS3, which successfully balances these competing demands. AlGaS3 crystallizes in a noncentrosymmetric structure composed of wide HOMO-LUMO gap [AlS4] tetrahedra and NLO-active [GaS4] tetrahedra. The compound exhibits a wide experimental optical band gap of approximately 3.38 eV, which is significantly larger than that of the benchmark AgGaS2 (AGS, ~2.70 eV). This wide band gap contributes to a high laser-induced damage threshold (LIDT) of approximately 6.0 times that of AGS, as determined by powder-based measurements. Notably, AlGaS3 also demonstrates a phase-matching SHG response of approximately 0.5 times that of AGS at a fundamental wavelength of 2.09 μm, with particle size-dependent behavior confirming phase-matchability. The combination of wide band gap, high LIDT, and moderate SHG response positions AlGaS3 as a promising candidate for high-power IR NLO applications. This work provides a viable strategy for designing IR NLO materials with enhanced laser damage resistance by incorporating wide-gap tetrahedral units.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3891-5
Alloys with low thermal expansion are vital for precision components in aerospace, cryogenics, optics, and electronics, where dimensional stability under thermal cycling is essential. As these applications face harsher mechanical and thermal conditions, materials must offer not only low thermal expansion but also high strength and ductility. Achieving all three remains difficult, as their underlying microstructural requirements often conflict. Here, we present a medium-entropy alloy, Fe54Ni34Co6Ti3Al3 (at.%), designed to overcome this challenge through tailored precipitation engineering. The alloy forms coherent L12 nanoprecipitates that not only provide substantial precipitation strengthening but also modulate the composition of the face-centered cubic matrix. This tuning induces a low coefficient of thermal expansion and metastability in the matrix, enabling transformation-induced plasticity that enhances ductility and strain hardening. As a result, the alloy achieves a tensile yield strength of (1036±21) MPa, uniform elongation of 18.4%±1.1%, and a coefficient of thermal expansion of 5.8×10−6 °C−1. This work demonstrates a precipitation-driven pathway to reconcile strength, ductility, and thermal stability, offering a new strategy for designing multifunctional structural materials for advanced engineering environments.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509095
Biotrickling filtration (BTF) is a promising technology for treating volatile organic compounds (VOCs), but its application to hydrophobic alkanes like isohexane is hindered by mass transfer limitations, low degradation efficiency, and high operational costs. To address these bottlenecks, this study developed composite fillers by incorporating biochars derived from coffee grounds (CG), coconut shells (CS), corn cobs (CC), and activated carbon (AC) into a polyvinyl alcohol-sodium alginate (PVA-SA) hydrogel matrix. The fillers were systematically characterized for water retention, pore structure, surface functional groups, crystalline phase, and acid-base resistance. Adsorption capacity, biofilm formation, and isohexane degradation were evaluated using the strain Rhodococcus ruber ZYH-ZY. Among the composites, CG@PVA-SA exhibited superior performance: water retention of 358 mg·g−1 (vs. 280 mg·g−1 for control), enhanced mesoporosity (specific surface area 4.77 m2·g−1, pore volume 11.46 cm3·kg−1, 10–30% higher than control), and robust acid-base stability (mass loss 21.37% at pH 2 and 31.98% at pH 10). Its saturated adsorption capacity reached 201.02 mg·kg−1 (vs. 114.24 mg·kg−1 for control), and it promoted bacterial colonization with a survival rate of 79.0% (vs. 37.2% for control). Static degradation tests showed 96.59% removal of 10 μL isohexane within 24 h. The abundant polar functional groups and suitable mesoporous structure of coffee ground biochar synergized with the PVA-SA matrix, enhancing water retention, mass transfer, and microbial colonization, thereby significantly improving isohexane purification. CG@PVA-SA is an ideal filler for BTF treatment of alkane VOCs, offering a cost-effective and efficient solution for industrial VOC control.