SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4302-9
The pre-deposited lead iodide (PbI2) film in two-step inverted perovskite solar cells (PSCs) often exhibits a dense structure, which impedes the diffusion and reaction of organic ammonium salts, leading to unreacted PbI2 residues and compromised device performance. To address this, 2,4-oxazolidinedione (OD) is introduced as a molecule additive into the PbI2 precursor solution. Owing to its stronger coordination with PbI2, OD effectively modulates its crystallization behavior, resulting in a porous structure. This porous structure significantly facilitates the diffusion and infiltration of organic ammonium salts, thereby minimizing PbI2 residue and enhancing the completeness of the perovskite conversion. Furthermore, OD and the constructed porous network jointly retard the crystallization kinetics of perovskite, promoting the formation of perovskite films with improved crystallinity and preferred crystal orientation. Therefore, the optimized PSCs achieve a power conversion efficiency (PCE) of 26.31%, and demonstrate excellent operational stability, retaining 90.24% of initial PCE for 1500 h at 25°C and 90.47% after 1000 h at 65°C. The champion device exhibits a VOC of 1.197 V, a JSC of 26.28 mA cm-2, and an FF of 83.58%, with negligible hysteresis. This study presents a straightforward yet effective approach to advancing the performance and stability of inverted PSCs fabricated via the two-step method.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024083002
Selenium (Se) is an essential trace element for human health, and dietary intake through Se-rich crops is the primary route. However, total soil Se content does not directly reflect the bioavailability to plants, which depends largely on soil available Se. This study, conducted in Shipai Town, Longshan County, Hunan Province, used 1:50,000 land quality geochemical survey data to investigate factors influencing the Se bioaccumulation coefficient in maize kernels. Soil pH, CaO, and MgO were identified as significantly positively correlated with the bioaccumulation coefficient and were selected as proxies for soil available Se. A random forest (RF) model was developed to predict maize grain Se content and assess the feasibility of cultivating Se-rich maize in low-Se farmland. Results showed that although soil Se was deficient, 53.64% of maize grain samples met the Se-rich product standard (0.02–0.30 mg·kg−1). Compared with multiple linear regression, the RF model exhibited higher accuracy and reliability. The RF model predicted that 40.91% of farmland in the study area is suitable for natural Se-rich maize cultivation, representing a 25.86% increase over the area identified by soil total Se alone. This study provides a novel methodological framework for planting natural Se-rich maize in Se-deficient regions, validating the potential for such cultivation.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3872-3
Flexoelectricity, the generation of electrical polarization in response to a strain gradient, is a fundamental electromechanical coupling mechanism that has gained significant attention due to its enhanced effects in ferroelectric materials, which exhibit large dielectric permittivities. This review comprehensively examines the classical theories and recent advances in flexoelectricity, with a primary focus on ferroelectric materials. We discuss the advantages and limitations of various characterization techniques, computational models for determining flexoelectric coefficients, and the mechanisms that enhance flexoelectricity in different ferroelectric systems. Furthermore, we explore the applications of flexoelectricity in devices, highlighting its potential to overcome the dimensional and stability limitations of piezoelectricity, particularly at the micro- and nanoscale. The review concludes by outlining future research directions, aiming to provide valuable insights for advancing both the fundamental science of flexoelectricity and the development of high-performance practical devices.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026020207
Although the production and use of hexabromocyclododecanes (HBCDs) have been completely banned in China since December 2021, historical production activities may still leave high-concentration residual contamination in localized areas. This study investigated a typical legacy site of historical HBCDs production in eastern China. Surface and core soil samples were systematically collected both inside and outside the former plant area to characterize the occurrence, spatial distribution, and environmental burden of HBCDs, and to evaluate associated human health risks. Results showed that HBCD concentrations in soils outside the plant area ranged from below detection limit to 6.90×10² ng·g⁻¹ dw, while those inside the plant area were substantially higher, reaching up to 1.18×10⁶ ng·g⁻¹ dw. γ-HBCD was the dominant isomer; however, its relative abundance was lower than that reported in commercial HBCD mixtures and in previous studies conducted near production facilities. Outside the plant, HBCDs concentrations in soil generally decreased with increasing distance from the site, yet remained detectable at a distance of approximately 10 km (15.2 ng·g⁻¹ dw). Within the plant area, HBCDs concentrations in soil cores decreased with depth, declining from 1.08×10⁴–1.18×10⁶ ng·g⁻¹ dw in surface soils to 1.05–93.5 ng·g⁻¹ dw at depths of about 4 m. Analysis of the relative cumulative environmental burden indicated that although HBCDs loads were highest in the near-source area, they gradually accumulated over a broader spatial scale. Approximately 23.7%, 40.1%, 60.0%, and 87.1% of the total estimated burden accumulated within 2 km, 2.81 km, 4 km, and 6 km from the site, respectively. Health risk assessment indicated that oral ingestion of soil was the primary exposure pathway for different populations. Localized high-contamination zones within the plant area contributed significantly to non-carcinogenic risks, while overall risks for children outside the plant area were at acceptable levels.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3975-2
The instability of oxygen redox activity in layered oxide cathodes, particularly the formation of localized electron holes on oxygen (O−) and subsequent anion dimerization, has been demonstrated to trigger rapid capacity degradation and severe voltage hysteresis. Our study primarily focuses on P3-type Na2/3Cu1/3Mn2/3O2, which demonstrates reversible oxygen redox with an exceptionally low voltage hysteresis of 0.05 V. Spectroscopic analyses demonstrate a reversible O2−→O− evolution in Na2/3Cu1/3Mn2/3O2 without O–O dimerization. Furthermore, Multilateral non-invasive magnetic methods reveal that strong Cu-O-Mn superexchange interactions during the metal-ligand redox process lead to delocalization of O− species and inhibition of irreversible O–O bonding, thereby enabling ultralow voltage hysteresis. This work establishes magnetic exchange engineering as a transformative strategy to unlock reversible oxygen redox in high-energy battery electrodes.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025042203
Cadmium (Cd) accumulation in crops is influenced by complex, crop-specific factors, posing challenges for the safe utilization of soils with elevated Cd levels. This study focused on a region with anomalously high soil Cd in northern Longshan County, Hunan Province, China. We systematically collected and analyzed Cd concentrations in the edible parts of lily (Lilium spp.) and maize (Zea mays L.), along with corresponding root-zone soil properties including Cd content, pH, and oxide levels. The bioconcentration factors (BCF-Cd) for lily and maize were compared, and their controlling factors were identified. Using random forest with hyperparameter optimization, optimal predictive models for BCF-Cd were developed for each crop. Results showed that lily BCF-Cd was significantly higher than that of maize. Key factors influencing BCF-Cd in both crops included soil pH, manganese (Mn), organic matter (OM), and the weathering-leaching coefficient (ba). Feature importance analysis identified soil pH as the most critical factor. Based on model predictions, a zoning scheme for safe arable land utilization was proposed to maximize land productivity while ensuring the medicinal safety of lily and food safety of maize. This study provides scientific support for enhancing food security and optimizing land resource use.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4163-y
Liquid metals (LMs) are promising catalyst systems due to their unique interfacial properties, yet migration and aggregation of active species cause performance degradation. Here, we report a composition optimization strategy using a Ga-In eutectic liquid metal support to reduce surface energy and achieve homogeneous incorporation of Cu species (GaIn-Cu). Comprehensive characterizations confirm uniform Cu dispersion, which inhibits migration and formation of CuGa2 intermetallic phases during CO2 electroreduction (CO2RR). The GaIn-10-Cu catalyst achieves a maximum CH4 Faradaic efficiency of 73.49% at -0.8 V vs. RHE, significantly higher than Ga-Cu (61.49%). Moreover, GaIn-10-Cu exhibits enhanced stability for CH4 generation over 40 h of continuous operation. In-situ spectroscopic studies reveal that GaIn-10-Cu favors formation and protonation of key *CHO and *OCH3 intermediates, steering selectivity toward CH4. This work demonstrates that tuning LM composition modulates catalytic site performance, offering a strategy for durable and selective LM-based electrocatalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4132-y
Manganese-iron-based mixed polyanionic cathodes are promising for sodium-ion batteries (SIBs) due to high energy density and operating voltage, but suffer from Jahn-Teller distortion of Mn3+ that degrades cycling stability. Here, a structural modulation strategy via Mg2+ doping is reported. Electrochemically inert Mg2+ forms stronger chemical bonds, adjusts lattice parameters, and suppresses Jahn-Teller distortion, enhancing structural stability. Mg2+ also widens sodium-ion diffusion channels, improving diffusion kinetics. Additionally, an in-situ three-dimensional carbon nanotube (CNT) conductive network boosts electronic conductivity. The resulting NFMPP-Mg@CNTs cathode delivers a discharge capacity of 126 mAh g−1 at 0.1 C (near theoretical 129 mAh g−1), retains 80% capacity after 3000 cycles at 0.5 C, and achieves an energy density of 401 Wh kg−1, among the highest reported for mixed phosphate systems. Ex-situ XPS and first-principles calculations confirm that Mg2+ resists geometric distortion by enhancing lattice stability and widening Na+ diffusion pathways (migration barrier reduced from 0.566 to 0.398 eV). This work provides a viable route for high-energy, long-life SIB cathodes suitable for large-scale energy storage.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3505-0
The synthesis of phase-pure 1T-WS2 remains a persistent challenge due to the thermodynamic metastability of the octahedral phase and the absence of a mechanistic understanding of the 2H-to-1T transformation at the atomic scale. This study demonstrates that when two 2H-WS2 grains with crystallographic orientation differences exceeding 10° are brought into contact at 1000 °C, they coalesce and transform into a single, pure 1T-WS2 grain devoid of orientation mismatch. First-principles calculations reveal a thermodynamic crossover at 280 K: below this temperature, 2H-WS2 is the stable phase, whereas above 280 K, 1T-WS2 becomes energetically favored. Kinetic analysis of nucleation shows that homogeneous nucleation of the 1T phase requires overcoming an energy barrier of 2.314 eV, while heterogeneous nucleation at the contact interface of two nanosheets necessitates only 0.005 eV, a reduction of nearly three orders of magnitude. This dramatic barrier lowering is attributed to the synergistic effect of elevated temperature and lattice mismatch-induced interfacial restructuring, which promotes atomic rearrangement and the formation of 1T-WS2 at the contact boundary. The 1T phase region subsequently expands, consuming the surrounding 2H nanosheets and yielding large-area, phase-pure 1T-WS2 films. This work establishes a straightforward, clean synthesis route for 1T-TMDs and provides a mechanistic framework for interface-driven phase engineering in two-dimensional materials.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3643-8
Inverted perovskite solar cells (PSCs) suffer from defect-mediated nonradiative recombination and inefficient charge extraction, particularly at the buried interface and grain boundaries (GBs), which limit power conversion efficiency (PCE) and operational stability. This study introduces a multifunctional phosphonic acid molecule, (2-(3,6-bis(trifluoromethoxy)-9H-carbazol-9-yl)ethyl)phosphonic acid (M28), as an additive in the perovskite precursor solution. M28 spontaneously segregates toward the buried interface and GBs, fulfilling three roles: (1) slowing crystallization to enlarge grains and improve film quality, (2) passivating defects to suppress charge recombination, and (3) inducing p-type doping to create an extra electric field that promotes hole transport. Devices incorporating M28 achieve a champion PCE of 25.96% and retain 80% of initial efficiency after 1500 h of maximum power point tracking. This work demonstrates the efficacy of multifunctional phosphonic acid additives in addressing buried-interface and GB defects, offering a viable route to high-performance, stable inverted PSCs.