SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4464-9
Topological polarization textures have transitioned from theoretical predictions to experimental observations over two decades, yet their stabilization has remained largely confined to low-dimensional architectures where geometric confinement balances depolarization, strain, and gradient energies. Extending these textures into bulk ferroelectrics and quantitatively linking them to macroscopic electromechanical properties constitutes a persistent challenge. Wu et al. address this by engineering vortex and antivortex domains in bulk rhombohedral 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-30PT) crystals. Phase-field simulations reveal that increasing vortex core density from 6 to 27 μm⁻² enhances the dielectric constant (ε33/ε0) and piezoelectric coefficient (d33) by approximately 3.5-fold and 3.4-fold, respectively, correlating with increased polarization curl. Experimentally, a mechanically assisted direct-current poling (MDCP) strategy elevates vortex core density from 0.01 to 21 μm⁻², boosting d33 from 1380 to 1820 pC·N⁻¹ and ε33/ε0 from 4,630 to 6,230. This mechanically driven approach enables controllable manipulation of topological domain architectures in bulk crystals without nanoscale confinement, offering a scalable route for functional optimization. The work establishes bulk ferroelectrics as a platform for topology-mediated electromechanical design, introducing an additional degree of freedom for enhancing piezoelectric performance in three-dimensional crystals.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4235-6
Fluorite-structured oxides (HfO2, ZrO2) are promising for resistive random-access memory (RRAM) due to their scalability and tunable properties. However, achieving high resistive switching on/off ratios remains challenging. Here, we report a collaborative strategy combining Hf/Zr ratio optimization and Lu3+ doping to regulate band structure and oxygen vacancy concentration in Hf0.4Zr0.6O2 (LHZO) thin films. The resulting LHZO devices exhibit a resistive switching ratio of 8.4 × 10^4, two orders of magnitude higher than that of ZrO2 (1.2 × 10^3). Electrical characterization and synchrotron radiation photoemission spectroscopy reveal that Lu doping widens the bandgap to 4.95 eV, downshifts the valence band, and introduces defect states, collectively suppressing p-type conductivity and reducing off-state leakage current. Simultaneously, Lu3+ doping enriches oxygen vacancies, stabilizing ohmic conductive filaments in the on-state. This co-optimization of band structure and oxygen vacancies effectively enhances insulating properties in the high-resistance state and ohmic conductivity in the low-resistance state, leading to superior resistive switching performance with robust retention (>10^4 s). Our findings establish a fundamental strategy for tailoring electronic properties of doped HfZrO2 thin films toward high-performance RRAM applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3625-3
Zirconia (ZrO2)-based fluorite ferroelectric materials are promising for nonvolatile memory and logic devices due to their CMOS compatibility and cost advantages over hafnium oxide (HfO2). However, the metastable nature of the ferroelectric orthorhombic phase (o-phase) hinders practical application. Here, we report the strain-mediated stabilization of the ferroelectric o-phase in ZrO2 thin films grown on niobium-doped strontium titanate (NSTO) substrates with different crystallographic orientations via chemical solution deposition. Systematic structural and ferroelectric characterization, combined with simulation, reveals that substrate orientation controls in-plane tensile strain, selectively promoting epitaxial growth of the o-phase. The ZrO2 film on NSTO(110) exhibits the highest o-phase content, achieving a remanent polarization (2Pr) of 92.64 μC/cm², which remains as high as 88.54 μC/cm² after resistive-capacitive (RC) delay calibration. The device shows endurance of approximately 10^7 cycles with favorable fatigue characteristics. X-ray absorption spectroscopy (XAS) further indicates distortion of Zr-O tetrahedra, providing microscopic insight into the ferroelectricity. This work presents a novel strategy for property tuning of ZrO2 films and supports their application in storage and logic devices.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025110501
Ultrashort-chain perfluoroalkyl substances (PFAS) exhibit high hydrophilicity, mobility, and root concentration factors, facilitating their transport and accumulation in soil-crop systems and posing phytotoxicity risks. Post-drought rehydration (PDR) is a critical water management strategy to mitigate drought effects in paddy fields. This study investigated the regulation and mechanisms of PDR on ultrashort-chain PFAS transport in paddy soils through sterilized and non-sterilized experiments, employing three-dimensional fluorescence spectroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray fluorescence spectroscopy, and amplicon sequencing. Results showed that PDR increased the bioavailable fraction of ultrashort-chain PFAS in soil solution while delaying their release into overlying water. Sterilization experiments confirmed that PDR-induced compensatory migration was primarily driven by microbial activity. Geochemical analyses revealed that PDR reduced hydrophilic functional groups (e.g., hydroxyl) on soil particle surfaces and increased cation bridging sites. Microbiological sequencing indicated that PDR activated secondary metabolic pathways, enhancing microbial extracellular polymeric substances (EPS) production, which provided binding sites for ultrashort-chain PFAS. Consequently, EPS competed with soil particles for cation bridging, altering PFAS interfacial partitioning and increasing bioavailable and cation-complexed fractions in soil solution, thereby exacerbating rhizosphere exposure risk to rice. This study elucidates the coupled geochemical and microbiological mechanisms governing ultrashort-chain PFAS mobility under PDR, informing risk assessment and management in paddy agroecosystems.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3850-3
Chiral nanomaterials have attracted considerable attention for antibacterial applications due to their unique chiroptical properties. Here, we report a novel spatiotemporally precise synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) strategy using circularly polarized light (CPL)-activated chiral molybdenum-doped carbon dots (L-Mo-CDs and D-Mo-CDs). These chiral carbon dots were synthesized using chiral tartaric acid as a precursor. Notably, D-Mo-CDs selectively respond to left-handed CPL (LCP), while L-Mo-CDs respond to right-handed CPL (RCP). Under CPL irradiation, D-Mo-CDs exhibit enhanced reactive oxygen species (ROS) generation and a higher photothermal conversion efficiency (PCE) compared to L-Mo-CDs. In vitro antibacterial assays demonstrate that D-Mo-CDs possess excellent bactericidal efficacy against both Gram-positive and Gram-negative bacteria. In vivo wound healing studies in a mouse model reveal remarkable therapeutic efficacy, attributed to reduced inflammation, accelerated angiogenesis, and enhanced collagen deposition. This work introduces a paradigm for utilizing chiral carbon dots in precision antibacterial therapy, addressing the limitations of conventional chiral nanomaterials such as poor biocompatibility and low photothermal conversion. The findings underscore the potential of metal-doped chiral carbon dots for advanced biomedical applications, offering a spatiotemporally controllable approach to combat bacterial infections without promoting resistance.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026011902
The migration of perfluoroalkyl and polyfluoroalkyl substances (PFASs) at the water–soil interface in paddy fields is a critical determinant of their environmental fate and crop safety. This study investigated the influence of low-molecular-weight organic acids (LMWOAs) on PFASs mobility under waterlogged conditions. Four LMWOAs—oxalic, citric, lactic, and acetic acids—were individually enriched in paddy soils, and the migration of 15 PFASs was monitored. Acetic acid enrichment most strongly suppressed PFASs release into overlying water. Mechanistic analyses using X-ray photoelectron spectroscopy, three-dimensional excitation–emission matrix spectroscopy, microbial amplicon sequencing, and metagenomics revealed that acetic acid reshaped the microbial community, enriching sulfate-reducing bacteria and upregulating sulfur reduction genes (SULT1A) and nitrogen transformation genes (nifN, nirI, nthB). This drove sulfate reduction to sulfite and sulfide. ABT modeling identified sulfur metabolism as the dominant factor controlling PFASs immobilization (26.06% contribution). Experiments under varying sulfur redox conditions confirmed that sulfite (SO3^2−) oxidation indirectly altered dissolved organic matter (DOM) composition, weakening PFASs–DOM binding and reducing PFASs in overlying water. These findings demonstrate that LMWOAs accumulation, particularly acetic acid, can effectively impede PFASs migration at the paddy water–soil interface via microbial sulfur cycling and associated DOM structural changes, offering a potential strategy for PFASs remediation in agricultural systems.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026021301
Lithium cobalt oxide (LCO) nanoparticles (NPs), generated during the lifecycle of LCO batteries via mechanical wear, pose respiratory health risks. This study systematically assessed LCO NPs' physicochemical properties, ion release, and immunotoxicity using multi-scale models. LCO NPs exhibited irregular morphology, layered crystal structure, good dispersion, and negative surface charge. Cobalt ion release was minimal: 1.03% in deionized water and 0.11% in cell culture medium. In vitro, LCO NPs significantly induced reactive oxygen species (ROS) production and secretion of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) in macrophages, promoting M1 polarization. In vivo, intranasal exposure caused dose-dependent pulmonary accumulation, alveolar destruction, inflammatory cell infiltration, and elevated cytokines in bronchoalveolar lavage fluid (BALF). Transcriptomic analysis revealed significant enrichment of NF-κB, JAK-STAT, and Toll-like receptor signaling pathways, implicating these in macrophage activation and inflammation amplification. This multi-level study elucidates LCO NPs' immunotoxicity mechanisms, providing a scientific basis for environmental health risk assessment and management of lithium-ion battery materials.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026041402
Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants ubiquitously distributed in paddy soils. In paddy management, surface water irrigation introduces quinolone antibiotics (QNs) into the soil, potentially altering PFAS interfacial migration via microbial community shifts. This study investigated the soil-water partitioning of PFAS under irrigation with four QNs (norfloxacin, ciprofloxacin, enrofloxacin, ofloxacin) using UHPLC-MS/MS and soil metagenomics. Results showed that QNs input, especially norfloxacin, significantly promoted the release of short-chain PFAS (e.g., PFBA) from soil to overlying water, while long-chain PFAS remained largely retained in soil. Metagenomic analysis revealed that archaeal and viral communities contributed most to PFAS release. Spearman correlations indicated ammonia-oxidizing archaea (Nitrososphaera) positively correlated with PFBA, whereas Bcep22virus negatively correlated with multiple PFAS. Differential gene expression and co-occurrence networks suggested QNs suppressed key functional genes in archaea and viruses (nitrogen metabolism, secretion systems, outer membrane proteins), reshaping interfacial partitioning and enhancing short-chain PFAS mobility, thereby increasing food security risks.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608025
To evaluate heavy metal contamination and human health risks in desert lakes, this study analyzed concentrations of seven heavy metals (Hg, Pb, Cu, Zn, Cd, Cr, As) in Hongjiannao Lake, Northern Shaanxi, from 2013 to 2024. The absolute principal component score-multiple linear regression (APCS-MLR) model quantitatively apportioned pollution sources, and a health risk assessment model evaluated non-carcinogenic and carcinogenic risks. Results showed average concentrations of the seven metals did not exceed background values, but 28.57% of sampling points exceeded background for As, with a maximum exceedance factor of 1.92. Total average concentration decreased from 112.51 μg/L (2013–2016) to 58.80 μg/L (2017–2024), attributed to the 2016 closure of small coal mines and ecological restoration around the 4A scenic area. Source apportionment identified four sources: industrial (35.44%), agricultural (24.67%), natural (23.65%), and traffic (16.23%), indicating industrial dominance. Non-carcinogenic risks were negligible, but carcinogenic risks exceeded the alert value (1×10⁻⁴), with adults at higher risk than children. Oral ingestion was the primary exposure pathway. As and Cd were key control elements, with exceedance rates of 100% and 16.67%, respectively. These findings provide a theoretical basis for health risk prevention and environmental management.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4009-0
Micro light-emitting diode (Micro-LED) display technology is a promising next-generation display technology due to its high brightness, high contrast, low power consumption, long life, and fast response. However, aggressive downscaling of Micro-LEDs to a few microns makes lift-off fabrication of metal bumps for soldered joints between Micro-LEDs and driver substrates increasingly difficult, challenging high-yield bump arrays under high-density conditions. This study innovatively replaces conventional metal bumps with a photosensitive conductive polymer (PCP), enabling fabrication of polymeric micro-bump arrays via well-established photolithography, bypassing complex lift-off processes and reducing short-circuit risk. Isopropyl alcohol regulates developer wettability for optimal development, yielding bump arrays with bump size 20 μm × 12 μm and height (1.9288 ± 0.0213) μm on thin-film transistor (TFT) drivers with yield over 99.99%. The issue of low bonding yield from polydimethylsiloxane (PDMS) thermal expansion was resolved by adjusting chip spacing on the temporary substrate, achieving bonding yield exceeding 99.8%. A 0.99-inch full-color Micro-LED display with density 114 pixels per inch (PPI) and brightness 5537 cd/m² was fabricated. High-yield bump arrays, Micro-LED arrays, and high bonding yield are highly reproducible, promoting development of Micro-LED displays and related fields.