SinoGreenTech Academic Portal
YL
Verified CAS / Academic Author6 Decoded Studies

Prof. YU Lei

Soochow University

Research Publications & English Decoded Briefs

Showing 6 publications
SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4235-6

High Resistive Switching On/Off Ratio in Lu-Doped Hf0.4Zr0.6O2 Thin Films via Band Structure and Oxygen Vacancy Co-Strategy

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 Materials2026DOI: 10.1007/s40843-026-4232-1

A comprehensive review on double-redox reaction towards high-performance polyanionic sodium-ion batteries

Polyanionic cathode materials are widely considered as potential cathode materials for sodium-ion batteries due to their strong three-dimensional framework and intrinsic thermal safety. Nevertheless, the limitation of the specific capacity and energy density hindered their application, which can be ascribed to the common reliance of single-electron redox reaction of the transition metal. By realizing the reversible double redox reaction of vanadium-based and manganese-based polyanion cathodes, researchers have successfully opened up a new way to break through the long-term performance limitations. Recent studies disclose that vanadium and manganese-based polyanionic cathodes exhibit the possibility of realizing a reversible double-redox reaction, which opened up new avenues to overcome the capacity dilemma. However, many fundamental issues remain unclear, including insufficient structural stability at high operating voltages, irreversible structural evolution induced by sodium extraction, sluggish electronic and ionic transport kinetics, and Jahn–Teller distortion. Therefore, it is imperative to summarize recent work in order to clarify the pathway for future investigation. In this review, the key challenges associated with the activation of the double-redox reaction are outlined, followed by the realization and regulation of the double-redox reaction in polyanionic cathode materials. A systematic summary of recent studies is performed for both vanadium and manganese-based compounds, which could contribute to the fundamental understanding of the double-redox reaction mechanism. Combined with the modification strategy and future perspective, this review provides insights into the rational design of polyanionic cathodes with a reversible double-redox reaction. It also offers insights into the development of high-energy-density cathode materials for next-generation sodium-ion batteries.

Journal of Fuel Chemistry and Technology2026DOI: 10.3724/2097-213X.2025.JFCT.0020

Cu3P@CuO Nanosheet Catalyst for Efficient Hydrolytic Hydrogen Production from Ammonia Borane

Ammonia borane (AB) is a promising hydrogen storage material due to its low molecular weight and high hydrogen content. The development of low-cost, high-activity catalysts for AB hydrolysis is critical for industrialization. In this work, CuO nanosheets (CuO NS) were synthesized via a solvothermal method under alkaline conditions using anhydrous copper chloride as precursor. Subsequently, low-temperature phosphating converted CuO NS into Cu3P@CuO nanosheets (Cu3P@CuO NS). The morphology and structure were characterized by SEM, TEM, AFM, XRD, and XPS. The catalytic performance for AB hydrolysis was evaluated, revealing that at a phosphating ratio of m(CuO NS)/m(NaH2PO2)=1 (0.1 g each), Cu3P@CuO NS exhibited excellent activity with a TOF of 57.23 min−1 and an apparent activation energy of 44.31 kJ/mol. The reaction followed pseudo-first-order kinetics with respect to catalyst amount and pseudo-zero-order kinetics with respect to AB concentration. The superior performance is attributed to the abundant active sites exposed by the nanosheet structure. Given the extremely low cost, Cu3P@CuO NS is a promising alternative to noble metal catalysts for hydrogen generation from AB.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3508-3

Laser-assisted compositional engineering of high-entropy carbides with superior oxidation resistance at 2500 °C

High-entropy carbides (HECs) are promising candidates for ultrahigh-temperature applications, but their oxidation resistance at temperatures above 2000 °C remains a critical bottleneck. Here, we report a laser-assisted compositional engineering strategy to develop non-equimolar (Zr0.2Ti0.2Ta0.3Cr0.3)C HECs with superior oxidation resistance up to 2500 °C. Using a self-developed laser oxidation platform, we first screened equimolar (Zr0.25Ti0.25Ta0.25Me0.25)C (Me = Hf, W, Nb, Cr, V, Mo) samples at 2500 °C, identifying Cr as a critical element for forming protective oxide scales. Systematic tuning of Cr content revealed that the optimal composition (Zr0.2Ti0.2Ta0.3Cr0.3)C exhibits a dense, crack-free oxide layer composed of molten (Cr, Me)(Ta, Me)O4 and (Ta, Me)2O5 phases embedded with (Zr, Me)O2 crystals, which effectively seal defects and suppress oxygen diffusion. The synergistic effects of these phases lead to a significant reduction in mass gain and oxide layer thickness compared to equimolar counterparts. This work provides a new pathway for designing HECs with long-life oxidation resistance at 2500 °C, enabling their use in extreme environments such as hypersonic vehicle leading edges and rocket nozzle throats.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3840-3

Distributed and stretchable tactile sensing for dexterous robotic hands based on a crosslinked interpenetrating network

Tactile sensing for dexterous robotic hands is essential for achieving human-like precision in manipulation. However, current tactile sensors face challenges such as insufficient durability, limited coverage, and poor conformability to curved, jointed surfaces. This study presents a stretchable distributed tactile sensor array designed for dexterous robotic hands. The array comprises 18 sensing units distributed across the hand, incorporating quasi-homogeneous functional layers interconnected by crosslinked interpenetrating networks, and composite electrodes combining high conductivity with stretchability. This design yields a thin, soft, transparent, and stretchable sensor array that integrates seamlessly with a commercial dexterous hand. The sensor array exhibits high interlayer tensile strength, high sensitivity, low hysteresis, and excellent long-term reliability over 10,000 loading cycles. Experimental results demonstrate accurate detection of tactile force across the entire robotic hand during object grasping. Using convolutional neural network algorithms, the sensor array identifies different object types with 90.1% accuracy, with results displayed in real time on a digital twin interface. The proposed sensor array holds significant potential for embodied intelligence and robotics in adaptive grasping, safe manipulation, and remote teleoperation.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4186-7

Simplified model for the melting point of oxides

The development of ultrahigh-temperature technologies, such as nuclear reactors, rocket nozzles, scramjet propulsion systems, and hypersonic vehicles, demands materials with melting points (Tm) exceeding 3273 K. However, the highest reported Tm among non-radioactive oxides is 3125 K (MgO), limiting progress. Existing predictive models for oxide Tm suffer from a trade-off between physical insight and practical utility: thermodynamic approaches require complex calculations, Lindemann's criterion relies on elusive parameters like Debye temperature, and semi-empirical correlations lack transferability. Machine learning models offer predictive power but lack interpretability and reliable extrapolation. Here, we simplify a previously derived semi-empirical model based on bond-breaking probability, which links Tm to effective potential barrier Ueff, proportional to bond length (d), bond density (Nb), and bond ionicity (fi). By analyzing a dataset of 68 oxides, we establish a simplified linear relationship between Tm and Ueff, expressed as Tm = 0.052Ueff + 122.6 K, with Ueff in kJ/mol. This model achieves a mean absolute error of 76 K and a coefficient of determination (R²) of 0.97, outperforming existing empirical models. The model's physical transparency and simplicity enable rapid screening of novel oxides, guiding the design of materials with Tm exceeding 3273 K. Our findings provide a practical tool for accelerating the discovery of ultrahigh-temperature oxides, addressing a critical bottleneck in next-generation thermal protection systems.