SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4245-4
The discrimination of volatile organic compounds (VOCs) at trace concentrations remains a critical challenge for environmental monitoring, industrial process control, and non-invasive disease diagnostics. Conventional electronic noses rely on sensor arrays comprising multiple chemically distinct receptors, which introduces fabrication complexity, calibration drift, and cross-sensitivity. Here, we demonstrate that a single-component Ti3C2Tx MXene (TM) sensor array, engineered through controlled surface chemistry and device architecture, generates independent and high-dimensional characteristics (IHC) sufficient for precise VOC pattern recognition. By exploiting the intrinsic heterogeneity of TM basal planes and edge sites, we achieve differential interaction motifs without expanding elemental composition. The array discriminates VOCs including acetone, ethanol, toluene, and hexane at concentrations down to 100 ppb with classification accuracy exceeding 95%. Principal component analysis reveals distinct clustering with cumulative variance of 92.3% captured by the first three principal components. The sensor exhibits a limit of detection of 50 ppb for acetone and response/recovery times of 12 s and 18 s, respectively. Long-term stability tests over 30 days show less than 5% signal degradation. This single-component strategy simplifies fabrication, reduces calibration overhead, and offers a scalable pathway for miniaturized, low-power VOC sensing platforms compatible with Internet of Things (IoT) deployment.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3946-2
High energy-density lithium–sulfur (Li–S) batteries with rapid intermediate conversion and forbidden shuttle effect require superior electrocatalysts with tunable catalytic activity. In this protocol, binary FeNi3 alloy nanoparticles homogeneously embedded within carbon nanosheets (FeNi3/CNS) are synthesized to regulate the conversions of sulfur species. Time of flight-secondary mass ion spectroscopy reveals a significantly improved catalytic effect of binary FeNi3 alloy compared to bare Ni, which is confirmed by a larger Li2S amount generated during in situ X-ray diffraction measurement. Further anode characterization validates efficient shuttling suppression and good lithium metal protection. In Li–S batteries, electrochemical tests demonstrate a remarkable rate capability of 852 mAh g−1 at 3.0 C, and outstanding long-term cycle at 1.0 C (639 mAh g−1 after 500 cycles). Even under a wide operation temperature range (−15–60 °C), Li–S batteries exhibit stable cycling with high specific capacities under high current rates. Moreover, Li–S batteries using FeNi3/CNS attain a maximum areal capacity of 5.60 mAh cm−2 under ~4.0 mg cm−2 sulfur. This study highlights the advantages of adopting binary or multi-component metal alloys as electrocatalysts and points out the research directions to advance Li–S batteries into practical applications.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3328-5
The recent synthesis of millimeter-sized hexagonal diamond (HD)-dominated bulk from highly oriented pyrolytic graphite (HOPG) at ~30 GPa and 1400 °C by Liu, Yao and co-workers represents a significant advance in superhard materials. The bulk exhibits a highly oriented microstructure, yielding an anisotropic Vickers hardness of up to 155 GPa, exceeding natural cubic diamond by over 40%. However, the proposed direct transformation mechanism from post-graphite to HD remains contentious. First-principles calculations indicate that C–C bond formation between graphite layers requires interlayer spacing below 2.5 Å, yet synchrotron X-ray diffraction shows that at 30 GPa (and even 50 GPa) the interlayer spacing is substantially larger. This discrepancy challenges the direct phase transformation pathway. An alternative mechanism involving coherent gradia interface formation and subsequent interface advance, previously established for graphite-to-diamond conversion, offers a more plausible explanation. Furthermore, achieving high HD volume fractions necessitates low synthesis temperatures, which impede sintering of large-angle grain boundaries between diamond grains, compromising toughness—particularly impact toughness. Future efforts must prioritize advanced sintering techniques, such as high-pressure flash sintering, to meet practical toughness demands. This commentary assesses the breakthrough, its unresolved mechanistic questions, and the critical barriers to industrial deployment.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3504-1
Anion exchange membrane water electrolyzers (AEMWEs) offer a cost-effective route for green hydrogen production by enabling non-precious metal catalysts and rapid start-stop operation. However, the trade-off between hydroxide conductivity and alkaline stability of anion exchange membranes (AEMs) remains a critical bottleneck. This study introduces a pyrene-based π-π stacking strategy to simultaneously enhance both properties. The synergistic π-stacking networks in the polymer backbone induce long-range cation aggregation through directed self-assembly, generating ionic cluster microdomains that elevate local hydroxide concentration and increase the density of accessible ion hopping sites. Additionally, the electron-donating effect of pyrene reduces the electrostatic potential of β-H adjacent to quaternary ammonium cations, raising the energy barrier for OH− nucleophilic attack. The resulting AEM exhibits exceptional performance: a hydroxide conductivity of 160 mS/cm and merely 0.35% conductivity degradation after 1950 h in 2 M KOH at 80 °C. The membrane electrode assembly (MEA) achieves a current density of 2.58 A/cm2 at 1.8 V and maintains stable operation for over 700 h in durability testing. These findings demonstrate a viable pathway for developing high-performance AEMs that meet the rigorous demands of industrial water electrolysis.