SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3800-7
Two-dimensional van der Waals (vdW) crystals, stacked via atomically thin layers, exhibit rich functionalities and tunable stacking orders. Their mechanical behaviors are crucial for flexible and miniature electronics. While some vdW crystals show superior plasticity, the mechanical properties of SnS2 bulk crystals remain largely unexplored. Here, we synthesize high-quality SnS2 crystals via the Bridgman method and comprehensively investigate their mechanical properties. SnS2 bulk crystals exhibit remarkable plasticity and softness: bending and compression strains exceed 20% and 45%, respectively, without fracture, while tensile fracture strains reach up to ~12% (range 9%–16%). Scanning/transmission electron microscopy reveals multiple deformation units, including layer segments, interlayer/cross-layer slip, twisting, and twinning-like structures. These units provide multiple pathways to release strain energy, promoting plasticity. Alongside weak interlayer vdW interactions, relatively ionic and weak intralayer Sn–S bonds contribute to the softness. This work fills the knowledge gap on SnS2 mechanical properties, advancing its processing and application in diverse electronic devices. Further studies may focus on balancing plasticity and strength by tuning microstructure to activate but confine deformation units.
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.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3969-9
Phosphor-in-glass (PiG) materials are promising color converters for high-power laser illumination, yet suppressing interfacial reactions between phosphor and glass matrix at elevated sintering temperatures remains a critical challenge. Here, we report a Y3Al5O12:Ce3+ (YAG:Ce) phosphor-in-silica glass (PiSG) with high SiO2 content (>85 wt%) fabricated via a Cs2CO3 flux. Incorporation of Cs2O significantly inhibits SiO2-YAG:Ce reactions, preserving internal quantum efficiency (IQE) at 97.7% of pure YAG:Ce, and achieving 88.3% IQE even after calcination at 1400°C for 2 h. In contrast, smaller alkali ions (Li+, Na+) accelerate YAG:Ce decomposition. Mechanistic studies reveal that Cs+ with large ionic radius and weak interaction with oxygen suppresses non-bridging oxygen (NBO) formation, promoting a complete silica network that limits alkali ion diffusion. Leveraging the mixed alkali effect (10% Li2O + 5% Cs2O), the PiSG exhibits enhanced hydrothermal stability, withstanding 200°C treatment for 10 h. A PiG film-sapphire device delivers 3080 lm luminous flux and 213 lm W−1 efficiency under blue laser excitation. These findings establish YAG:Ce-PiSG as a highly promising color-conversion material for high-performance laser illumination.