SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3660-5
High-sensitivity piezoelectric ceramics with high piezoelectric constants (d33) are crucial for miniaturized, low-power, and high-efficiency transducers. However, conventional performance enhancement relies on intrinsic parameter modulation, which is limited and blind. This study introduces a performance-driven metamaterials creation model to develop structure-function-integrated piezoelectric materials. We systematically investigated the effects of metastructure design on d33 across two-dimensional straight rod (SR) structures, three-dimensional dot-matrix (Octa) structures, complex triply periodic minimal surface (TPMS) structures, and hybrid Octa&SR structures. The results demonstrate that metastructures combining high polarization charge conversion efficiency with low compression modulus (stiffness) effectively enhance d33. The SR structure exhibited optimal polarization charge conversion, the Fks-Shellular (FksS) structure within TPMS showed low stiffness, and the Octa&SR structure combined both properties. Notably, all three structures displayed exceptional piezoelectric performance. Specifically, the FksS structure achieved a substantial d33 of 194 pC/N, a 24% enhancement over conventional solid BaTiO3, while maintaining isotropic and stress-insensitive properties. This work elucidates the mechanism for designing piezoelectric metastructures, offering a novel pathway for developing high-performance, high-failure-strength piezoelectric materials.
Environmental Chemistry•2026•DOI: 10.0000/202605-1
A method for the determination of hydrazoic acid and sodium azide in workplace air was established using ion chromatography with suppressed conductivity detection. Vapor and mist states of hydrazoic acid were collected in 40 mg·L−1 KOH absorption solution, while sol states of hydrazoic acid or sodium azide were collected on microporous membranes and eluted with 40 mg·L−1 KOH. Separation was performed on a Dionex IonPac™ AS11-HC (250 mm × 4.0 mm) anion analytical column with KOH gradient elution, followed by suppressed conductivity detection. The azide ion (N3−) exhibited good linearity in the range of 0.005–0.5 mg·L−1, with a correlation coefficient (r) of 0.9997. The limit of detection (S/N=3) was 0.002 mg·L−1, and the limit of quantification (S/N=10) was 0.005 mg·L−1. The minimum quantifiable concentrations in air were 0.00256 mg·m−3 for hydrazoic acid and 0.00387 mg·m−3 for sodium azide, based on a 10.0 mL sample solution and a 20 L air sample. Spiked recoveries ranged from 92.0% to 100.4%, with relative standard deviations (RSD, n=6) between 0.76% and 2.51%. The method is efficient, accurate, and sensitive, suitable for monitoring and safety assessment of hydrazoic acid and sodium azide in workplace air.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025032601
This study investigated the pollution characteristics of chlorate and perchlorate in tea from Anhui region and assessed the health risks associated with tea consumption. A total of 132 tea samples, including green tea (n=89), black tea (n=30), yellow tea (n=10), and white tea (n=3), were collected from major tea-producing areas. Chlorate and perchlorate levels were quantified using isotope dilution liquid chromatography-tandem mass spectrometry. Chlorate was detected in 15.9% of samples, with concentrations ranging from not detected to 0.040 mg·kg−1, and no samples exceeded the regulatory limit. Perchlorate was detected in 100% of samples, with concentrations ranging from 0.011 to 1.611 mg·kg−1, and 2.3% of samples exceeded the limit. Pollution characteristics analysis revealed that perchlorate levels were significantly correlated with tea type and geographical origin, with environmental contamination in tea-growing areas being the primary determinant. A significant positive correlation was also observed between chlorate and perchlorate levels. Health risk assessments were conducted for the general tea-consuming population, sub-groups loyal to specific tea types (green and black tea), and sub-groups preferring local tea from high-pollution regions (Lu'an City and central Anhui). Assessments were based on mean and 95th percentile (P95) exposure levels. For chlorate, the maximum hazard quotient (HQ) was 0.003, far below 1, indicating negligible risk. For perchlorate, all HQ values were below 1, regardless of tea type or region, based on both mean and P95 levels, using the Chinese provisional tolerable daily intake (tTDI). However, perchlorate contamination in central Anhui, particularly Lu'an City, warrants continued monitoring due to elevated levels and occasional exceedances.