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Verified CAS / Academic Author8 Decoded Studies

Prof. CHENG Mengyuan

University of Science and Technology of China

Co-Affiliations:School of Materials Science and Engineering, Tianjin UniversitySchool of Materials Science and Engineering, Beijing Institute of TechnologySchool of Chemistry and Environment, Yunnan Minzu University, Kunming 650504, ChinaSchool of Ecology and Environment, Tibet University, Lhasa 850000, ChinaSchool of Physics, Liaoning University, Shenyang 110036, ChinaEast China University of Science and Technology

Research Publications & English Decoded Briefs

Showing 8 publications
SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4500-8

Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene

Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3628-3

Regulating Solution Aggregation and Entanglement for Efficient Self-Powered All-Polymer Photodiodes in Water Quality Monitoring

The solution aggregation structures of conjugated polymers are pivotal in determining their film morphology and optoelectronic properties, yet the relationship between solution aggregation and device performance remains elusive in organic photodiode (OPD) systems. Herein, we introduce the first examination of solution aggregation structures of all-polymer OPD blends, with a focus on how molecular entanglement modulates aggregation behavior and subsequent photodiode performance of low-cost poly(3-pentylthiophene). Using small-angle neutron scattering and freeze-dried imaging, we provide a comprehensive analysis of the solution-state aggregation behavior of poly(3-pentylthiophene) and its evolution in the blend, revealing profound impacts on film morphology and device performance. With finely optimized aggregation, the resulting all-polymer OPD achieves a record-high specific detectivity of ~4×10^13 Jones at zero bias, outperforming all bulk heterojunction (BHJ)-type self-powered OPDs reported to date. This device also demonstrates remarkable thermal stability, with negligible performance degradation after over 800 h of thermal annealing at 85 °C. Furthermore, the self-powered OPD exhibits excellent performance across a broad spectral range, enabling its application in both water quality monitoring and biosensing. This work offers new insights into the solution aggregation behavior of conjugated polymers in OPDs and highlights the importance of resolving solution aggregation in optimizing device function.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3625-3

Strain Modulation of ZrO2 Ferroelectric Thin Films for Achieving Superior Polarization

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.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202507021

Health Risk Assessment of Heavy Metals in Soil Around a Landfill Based on Monte Carlo Simulation

The accumulation of heavy metals in soil around municipal solid waste landfills poses potential risks to human health. This study selected a municipal solid waste landfill and monitored the concentrations of eight heavy metals (Zn, Pb, Cd, Ni, Hg, Cu, As, Cr) in surrounding soil. The geo-accumulation index method was used for pollution assessment, and a health risk assessment model recommended by the USEPA, combined with Monte Carlo uncertainty analysis, was employed to evaluate the pollution status and health risks to nearby residents. Results showed that among the eight metals, Pb, Ni, and Cd exceeded risk screening values at 4.26%, 6.38%, and 4.26% of sampling points, respectively. Geo-accumulation indices indicated overall clean conditions (mean < 0), but slight pollution by Pb, Zn, Ni, Hg, and Cd at some points. Probabilistic risk assessment based on Monte Carlo simulation revealed that for both adults and children, the cumulative non-carcinogenic risk was negligible, while carcinogenic risk was acceptable. However, there was a very low probability (approximately 0.2%) of non-carcinogenic risk for children, and probabilities of unacceptable carcinogenic risk were 0.64% for adults and 3.21% for children. Nickel was the primary contributor to carcinogenic risk, and children faced higher health risks than adults. These findings provide a reference for pollution prevention and health risk management of soil around municipal solid waste landfills.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3599-5

Tellurium vacancy-rich Bi2Te3 as a high-performance cathode material for aqueous zinc ion storage

Layered transition metal tellurides (TMTs) are promising cathode materials for aqueous zinc ion batteries (AZIBs) due to their graphite-like layered structure and weak van der Waals interactions, which facilitate rapid ion transport. However, their holistic performance—specific capacity, rate capability, and cycling stability—remains insufficient for practical applications. Here, we report a straightforward NaBH4-assisted chemical etching method to introduce abundant Te vacancies on the surface of Bi2Te3 (denoted H-Bi2Te3). Experimental and theoretical analyses reveal that these Te vacancies refine the band structure, enhance electrical conductivity, and significantly reduce the diffusion barrier for Zn2+ ions. Additionally, the vacancies provide increased storage sites for Zn ions. Consequently, H-Bi2Te3 exhibits superior zinc storage performance: a high Zn2+ diffusion coefficient of 3.98×10−11 cm2 s−1, a specific capacity of 325 mAh g−1 at 0.1 A g−1, a rate capability of 217 mAh g−1 at 1 A g−1, and exceptional cycling stability with 70 mAh g−1 retained after 10,000 cycles at 1 A g−1. This work introduces a novel vacancy defect engineering strategy for TMT-based cathodes in AZIBs and expands the potential applications of vacancy-rich TMT materials.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202508050

Spatial Differentiation of Heavy Metals in a Landfill Site in a High-Altitude Cold Region Driven by Freeze-Thaw Cycles

This study investigated the spatial distribution and ecological risk of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) in soil beneath an informal waste dump in a pastoral area of Baingoin County, Nagqu City, Tibet, a high-altitude cold region with frequent freeze-thaw cycles. A total of 55 soil samples were collected from surface (0 cm), middle (10-30 cm), and deep (50 cm) layers. Single-factor index (Pi), geo-accumulation index (Igeo), Nemerow index (PN), and risk assessment code (RAC) were employed to evaluate contamination levels and potential ecological risks, while Kriging interpolation was used to map spatial distribution. Results showed that average concentrations of all seven heavy metals exceeded local background values. Horizontally, high-concentration zones were mainly located at five points within the dump. Vertically, Cd, Cu, Pb, and Zn were significantly enriched in the surface layer, whereas Ni exhibited higher concentrations in deeper layers, indicating downward migration driven by freeze-thaw processes. All evaluation methods identified Cd as the primary pollutant. Speciation analysis revealed that heavy metals were predominantly in the residual fraction, with Ni having the highest weak-acid-extractable fraction (5.55%), indicating strong mobility and potential biological toxicity. This study fills a gap in systematic research on informal waste dumps in high-altitude ecologically fragile areas and provides a case reference for environmental management and remediation of such sites in cold regions.

Journal of Fuel Chemistry and Technology2026DOI: 10.1016/S1872-5813(26)60647-0

Interface Regulation for Enhanced Photoelectrochemical Performance of CuBi2O4 Photocathodes

Photoelectrochemical (PEC) water splitting offers a direct route to convert solar energy into clean hydrogen fuel. CuBi2O4, a p-type semiconductor with a bandgap of 1.5–1.8 eV, exhibits visible-light responsiveness and good stability, yet its performance is limited by high interfacial resistance and severe charge carrier recombination. This study introduces a CuO interlayer between fluorine-doped tin oxide (FTO) and CuBi2O4 to construct CuO/CuBi2O4 photocathodes, aiming to improve interfacial charge transfer. The optimized CuO/CuBi2O4-200 photocathode achieved a photocurrent density of −1.71 mA/cm² at 0 V vs. RHE, more than 3.5 times that of bare CuBi2O4. Incident photon-to-current efficiency (IPCE) at 365 nm reached ~13%, and the maximum applied bias photon-to-current efficiency (ABPE) was 0.17%. Water splitting experiments yielded 2.05 μmol/cm² of hydrogen, significantly surpassing the unmodified photoelectrode. Mechanistic studies indicate that the CuO layer establishes favorable band alignment, promotes hole transport toward the FTO substrate, and suppresses interfacial carrier recombination. This work demonstrates a simple and efficient interfacial engineering strategy, offering insights for the design of high-performance semiconductor-based PEC photoelectrodes.

Environmental Chemistry2026DOI: 10.7524/j.issn.0254-6108.2025011804

Single-Molecule Electrochemical Analysis of Per- and Polyfluoroalkyl Carboxylic Acid Isomers

Per- and polyfluoroalkyl carboxylic acids (PFCAs) are persistent organic pollutants whose isomers exhibit distinct environmental behaviors, bioaccumulation potentials, and toxic effects due to structural variations. Accurate identification of PFCA isomers is critical for risk assessment and pollution control, yet existing detection methods predominantly rely on standard references, posing challenges for precise analysis of isomers with subtle structural differences. Single-molecule electrochemical sensing via nanopores offers a standard-free approach by correlating molecular volume with current blockade, but its capability to distinguish PFCA isomers remained unverified. This study targeted three sets of PFCA isomers: 4,5,5-trifluoropent-4-enoic acid vs. 4,4,4-trifluoro-3-methylbut-2-enoic acid; 3,3,3-trifluoro-2-methylpropanoic acid vs. 4,4,4-trifluorobutanoic acid; and 2-(trifluoromethoxy)acetic acid, 3,3,3-trifluorolactic acid, and (2R)-3,3,3-trifluoro-2-hydroxypropanoic acid. By engineering nanopore interfaces (WT, R220N, R220Q Aerolysin) and extracting multi-dimensional characteristic parameters, the method achieved near 100% accuracy in identifying all seven isomers. Feature selection further enabled high classification accuracy with low data volumes, laying the foundation for rapid single-molecule detection of PFAS and other emerging contaminants.