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Verified CAS / Academic Author9 Decoded Studies

Prof. XU Xuefeng

School of Municipal and Environmental Engineering, Shenyang Jianzhu University

Research Publications & English Decoded Briefs

Showing 9 publications
SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4302-9

Facilitated Diffusion of Organic Ammonium Salts via OD-Induced Porous PbI2 for Efficient Two-Step Inverted Perovskite Solar Cells

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.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3785-5

Redox dual-cocatalysts modified ZnIn2S4 hollow sphere with spatially separated carrier for photocatalytic H2 production coupled with selective benzyl alcohol oxidation

The effective separation and utilization of photo-generated carriers are critical for advancing photocatalysis, particularly in coupled reactions of H2 production and value-added chemical synthesis. Here, a sandwich-structured MnO2@ZnIn2S4@Ti3C2 hollow sphere was designed, with MnO2 and Ti3C2 loaded on the inner and outer surfaces of ZnIn2S4, respectively. MnO2 acts as an oxidation cocatalyst collecting photo-generated holes, while Ti3C2 serves as a reduction cocatalyst for electrons, promoting spatial separation of carriers and enabling spatially separated redox reactions. The hollow structure enhances light harvesting. The optimal catalyst achieves photocatalytic H2 production rate of 6.29 mmol g−1 h−1 and benzaldehyde production rate of 5.26 mmol g−1 h−1 from benzyl alcohol oxidation, significantly outperforming ZnIn2S4, MnO2@ZnIn2S4, and ZnIn2S4@Ti3C2. In situ irradiated X-ray photoelectron spectroscopy confirms effective carrier separation. In situ electron paramagnetic resonance and diffuse reflectance infrared Fourier transform spectroscopy reveal reaction intermediates. This work provides a strategy for designing efficient photocatalysts for coupled H2 production and selective oxidation.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202507111

Pulsed Electric Field Enhancement of Nitrogen Removal Performance and Microbial Community Structure Response in Anammox Granular Sludge

This study investigated the effects of a ring-shaped pulsed electric field (PEF) (1.5 V, 4 h on-time per cycle) on nitrogen removal performance and microbial community structure of anammox granular sludge (AnGS). Two anaerobic sequencing batch reactors (R1 control, R2 with PEF) were operated under stepwise increasing nitrogen loading rates (NLR). At NLR below 1,155 mg·(L·d)−1, R2 exhibited total nitrogen removal efficiency (TRE) 7.5%–17.0% higher than R1, with biomass, specific anammox activity (SAA), and extracellular polymeric substances (EPS) increased by 5%–7%, 21%–71%, and 54%–77%, respectively. However, at NLR above 1,320 mg·(L·d)−1, the toxic effect of nitrite dominated, and PEF enhancement diminished or even reversed to inhibition. Microbial community analysis revealed that at low-to-moderate NLR, PEF increased the relative abundance of Planctomycetes and key anammox bacteria (Candidatus Brocadia and Candidatus Jettenia), along with enhanced community richness (Chao1) and diversity (Shannon/Simpson indices). At high NLR, PEF decreased microbial richness compared to R1. Principal component analysis and redundancy analysis indicated that PEF was the key factor driving community differences at low-to-moderate NLR, whereas nitrite concentration became the dominant factor at high NLR. This study provides theoretical support for enhancing the resilience and engineering application of anammox processes.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202507059

Application of Immobilized White Rot Fungi in the Treatment of Anaerobic Digestion Sludge

Anaerobic digestion sludge (ADS) contains recalcitrant organic matter and exhibits poor dewaterability, posing challenges for disposal. This study evaluated the immobilization of white rot fungi (WRF) on four carriers—polyvinyl alcohol, cotton thread, wood chips, and sodium alginate—for ADS treatment. Cotton thread immobilization yielded the earliest and most sustained enzyme activity, highest biomass retention, and minimal biomass loss. WRF treatment achieved a 10.09% removal of total chemical oxygen demand (TCOD) and significantly disrupted extracellular polymeric substances (EPS), selectively degrading soluble EPS. To maintain fungal activity, periodic carrier replacement was required. Compared to the control, the experimental group showed an 8.9 mg·L−1 reduction in total protein and polysaccharide content in soluble EPS, a 27.33% decrease in capillary suction time (CST), and improved sludge dewaterability. These results demonstrate the potential of WRF for ADS treatment.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3830-6

Helical wrapping and charge-transfer driven multi-stranded crystalline helices from a twisted figure-of-eight macrocycle

Controlled fabrication of artificial multiple-stranded helices is central to deciphering chirality complexity and hierarchical self-assembly processes. Inspired by biological helical nanostructures, we designed a twisted figure-of-eight chiral macrocycle (M1) from pyrene and benzene diimide subcomponents to direct hierarchical assembly of double- and quadruple-stranded superhelices. Single-crystal X-ray diffraction reveals that M1 undergoes charge-transfer and CH···π interactions-driven helical wrapping, forming right-handed (P) single strands that intertwine into quadruple π-helical superstructures. Crucially, the macrocycle's adaptive cavity and interstitial voids could bind electron-deficient naphthalene diimide (NDI) guests through charge transfer interactions, triggering transformation to left-handed (M) double helices. This structural shift induces helicity inversion and optical anisotropy changes, demonstrating a rare case of crystalline-state multiple-helix conversion with supramolecular chirality inversion. This work establishes a template-free methodology for synthesizing multiple-stranded π-helices and controlling their transformations through supramolecular engineering.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3879-5

Single-Stimulus Modulation of Multimodal Circularly Polarized Luminescence in Helical Ferroelectric Liquid Crystals

Stimuli-responsive circularly polarized luminescence (CPL) materials are pivotal for investigating excited-state chirality and advancing optoelectronic applications. However, achieving comprehensive modulation of chiroptical properties within a single system under a single external stimulus remains a significant challenge. Here, electric-field-responsive helical ferroelectric liquid crystals are developed by incorporating diverse chiral emitter dopants into the prototypical liquid crystal mesogen 2,3′,4′,5′-tetrafluoro-[1,1′-biphenyl]-4-yl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl)benzoate (DIO), known for its high dielectric anisotropy and multiple mesophases. By co-doping different types of chiral molecules with opposite handedness, a competitive chiral field is generated that responds differentially to the applied voltage, enabling continuous modulation of the helical pitch and reversible inversion of handedness. This work provides the integrated demonstration of single-stimulus regulation of on/off gating, magnitude tuning, and reversible sign inversion in a single liquid-crystal system, opening a pathway toward intelligent chiroptical materials.

Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202511003

Research Progress on Combined Stress Effects of Secondary Water Pollution from Tailings Dam Leakage on Aquatic Organisms

Tailings dam leakage can cause secondary sudden water pollution events, imposing severe combined stress of high turbidity and heavy metal contamination on natural water bodies within a short period, threatening aquatic ecological security. Existing studies have systematically revealed the pollution characteristics and biological effects of such events, which are fundamentally distinct from natural high-turbidity water and industrial wastewater leakage. Compared with natural high-turbidity water, tailings leakage inputs finer particles with higher specific surface area, leading to more intense and prolonged turbidity stress. Meanwhile, heavy metals in tailings are more enriched than natural sediments, with higher proportions of active forms and bioavailability, causing significant bioaccumulation and toxic effects, and long-term decline in benthic community species richness. Compared with industrial wastewater leakage, tailings leakage simultaneously releases high concentrations of fine suspended solids and multiple heavy metals, forming a unique 'physical-chemical' combined stress. This synergistic effect amplifies biological toxicity through multiple pathways such as mechanical damage, light limitation, and oxidative stress, resulting in severe and often irreversible ecological damage, such as impaired fish swimming behavior and collapse of benthic community structure. Analyzing the long-term impacts of tailings leakage on aquatic ecosystems from the perspective of combined stress is helpful for providing scientific basis for emergency response and medium-to-long-term ecological risk prevention of related sudden water pollution events.

Journal of Fuel Chemistry and Technology2026DOI: 10.1016/S1872-5813(26)60653-6

Study on the coke deposition characteristics of hierarchical ZSM-5 zeolites with synergistic regulation of pore structure and temperature in benzene catalysis

Carbon deposition caused by mass transfer limitations is a key challenge for traditional microporous ZSM-5 zeolites in coal tar catalytic cracking. To address this, benzene was used as a model compound. Parent ZSM-5 (NL-ZSM-5) was modified with tetraethylammonium hydroxide (TEAOH) to prepare hierarchical ZSM-5 zeolites with different mesopore sizes. Characterization (XRD, FT-IR, BET, TEM) confirmed successful mesopore introduction via selective desilication while retaining the MFI structure. At TEAOH concentration of 0.4 mol/L (ZSM-5-C), total pore volume increased from 0.24 to 0.43 cm3/g, and Brønsted acid amount increased from 0.28 to 0.67 mmol/g, with improved acid site accessibility. Catalytic experiments and carbon deposition analysis showed that hierarchical pore structure inhibits coking via a synergistic effect of diffusion enhancement and adsorption-site regulation. The coke amount of ZSM-5-C was 4.0%, only one-third of that of NL-ZSM-5 (11.9%). Molecular dynamics simulations confirmed that the diffusion coefficient of benzene in a 3.0 nm mesopore model is an order of magnitude higher than in a 2.0 nm model. Adsorption capacity decreases with increasing mesopore size, shortening residence time. Increasing temperature enhances diffusion but exponentially intensifies surface condensation reactions (Arrhenius effect), which dominates coke formation; hierarchical pores mitigate this negative effect. This research provides a theoretical basis for designing high-efficiency, coke-resistant catalysts for coal tar conversion.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4144-y

Room-Temperature Sensitive Electromechanical Magnetization Reversal with Modulation Capability Approaching 100%

Developing efficient strategies for electrically manipulating two-dimensional magnetism at room temperature is a key challenge in contemporary spintronics. In this study, we demonstrate giant electromechanical control over the magnetism of the room-temperature van der Waals ferromagnet Fe3GaTe2 by integrating it with the ferroelectric α-In2Se3. Modest gate voltages lead to an almost complete suppression of the coercive field by 96.5%, corresponding to a remarkable peak modulation sensitivity of ~8.1 mT V−1, which stands out among existing van der Waals magnetoelectric systems. Importantly, this substantial magnetoelectric response is predominantly unaffected by voltage polarity, as both positive and negative gate voltages induce similar magnetic modulation effects. To elucidate the underlying mechanism, we tracked the voltage-induced Raman spectral changes, revealing a peak shift of 1.7 cm−1 that accurately represents an effective in-plane tensile strain of ~1.42% under an equivalent bias, demonstrating polarity independence as well. The synchronized magnetic response and strain variation unequivocally indicate that the induced tensile strain serves as the fundamental physical driver behind the magnetic modulation. Additionally, density functional theory calculations corroborate that the reduction in magnetic anisotropy induced by tensile strain results in a decrease in the coercive field. Our work establishes a novel and efficient approach for achieving voltage control of magnetism at room temperature in van der Waals multiferroic heterostructures, highlighting their significant potential for applications in ultra-low-power magnetic logic and sensing technologies.