Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024122001
Biomass is the only renewable carbon resource with huge reserves and wide sources, and it is green and environmentally friendly. Under the background of 'dual carbon', the clean and efficient utilization of biomass has received increasing attention. Preparation of biochar from biomass is one of the main methods to use biomass efficiently. Biochar surfaces possess porous and aromatic structures, which exhibit good fixation effects on heavy metals in wastewater. However, biochar has shortcomings such as difficulty in recovery and non-reusability. The introduction of iron into biochar can not only enrich surface functional groups, develop pore structure, and increase specific surface area, but also endow magnetic properties, facilitating solid-liquid separation after adsorption. This paper reviews the preparation methods of iron-based magnetic biochar (MBC-Fe), summarizes the effects of different iron sources on its characteristics, and illustrates the adsorption performance and mechanisms of MBC-Fe for typical heavy metals in water. Finally, applications of MBC-Fe in the removal of heavy metal ions from wastewater are concluded, and future utilization potential in other fields is proposed. The review highlights that MBC-Fe exhibits high adsorption capacities, e.g., for Pb(II) and Cd(II), with rapid kinetics and easy separation, making it a promising adsorbent for wastewater treatment.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3935-1
Silk fibroin (SF)-based hydrogels are promising for biological interfaces, yet achieving multifunctionality—mechanical robustness, adhesion, conductivity, and stability—often requires chemical modification that compromises biocompatibility. Here, we report a protonation-mediated SF/polyvinyl alcohol (PVA) hydrogel adhesive that retains natural silk properties while gaining tailored functionalities. The physically crosslinked network is formed solely via molecular interactions, with phosphoric acid (H3PO4) as a protonation agent to modulate hydrogen bonding, enabling precise control over adhesion, mechanical strength, and electronic conductivity. Glycerol (Gly) is incorporated as a moisturizing agent to enhance long-term stability for skin applications. The resulting hydrogel exhibits excellent performance in monitoring electrophysiological signals, including electrocardiogram (ECG), electromyogram (EMG), and electroencephalogram (EEG), demonstrating its potential as a platform for advanced biological interfaces. This work addresses the critical challenge of developing SF-based hydrogels that combine natural advantages with multifunctionality, offering a promising route for wearable health monitors and human-machine interfaces.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3407-0
Grain boundary (GB) engineering has emerged as a promising strategy to enhance the near-room-temperature performance of Mg3(Sb,Bi)2-based thermoelectric materials, yet effective control of Mg distribution at GBs remains a significant challenge. Here, we report a novel approach to achieve targeted Mg segregation at GBs through strategic Ag incorporation in Mg3.3Sb0.5Bi1.497Te0.003. Through comprehensive microstructural characterization and first-principles calculations, we demonstrate that Ag preferentially segregates at GBs, forming Mg-rich MgAg alloy phases while maintaining limited solid solubility within the matrix. This unique GB architecture simultaneously optimizes multiple thermoelectric parameters: the Mg-rich GB regions significantly provide efficient carrier transport channels and enhance carrier mobility, while the MgAg phases and lattice disorders effectively scatter phonons without disrupting electron transport. Consequently, the optimized composition (x = 0.01) exhibits a remarkable enhancement in power factor at 300 K and maintains an average ZT of ~1.0 across 300–400 K. The material also demonstrates excellent mechanical properties and thermal stability, making it particularly suitable for near-room-temperature applications. Our findings not only establish an effective strategy for GB engineering in Mg3(Sb,Bi)2 systems but also provide valuable insights into the rational design of high-performance thermoelectric materials through interface modification.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3800-7
Two-dimensional van der Waals (vdW) crystals, stacked via atomically thin layers, exhibit rich functionalities and tunable stacking orders. Their mechanical behaviors are crucial for flexible and miniature electronics. While some vdW crystals show superior plasticity, the mechanical properties of SnS2 bulk crystals remain largely unexplored. Here, we synthesize high-quality SnS2 crystals via the Bridgman method and comprehensively investigate their mechanical properties. SnS2 bulk crystals exhibit remarkable plasticity and softness: bending and compression strains exceed 20% and 45%, respectively, without fracture, while tensile fracture strains reach up to ~12% (range 9%–16%). Scanning/transmission electron microscopy reveals multiple deformation units, including layer segments, interlayer/cross-layer slip, twisting, and twinning-like structures. These units provide multiple pathways to release strain energy, promoting plasticity. Alongside weak interlayer vdW interactions, relatively ionic and weak intralayer Sn–S bonds contribute to the softness. This work fills the knowledge gap on SnS2 mechanical properties, advancing its processing and application in diverse electronic devices. Further studies may focus on balancing plasticity and strength by tuning microstructure to activate but confine deformation units.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605024
The refined quantification of carbon footprint in engineering construction projects is critical for formulating targeted carbon reduction strategies during the materialization phase. This study integrates material flow analysis (MFA) with the emission factor method to establish a panoramic carbon flow model for engineering projects. Construction activities are categorized into processing and construction, and office and daily operations, clarifying material and carbon flow relationships within the system boundary and with external systems. Empirical analysis was conducted on the Hejiawan Bridge of Section 11 of the Xiyu High-Speed Railway. Results show that the total carbon flow amounts to 27,482,432.11 kg CO2eq, with direct carbon flow (fuel oil, gasoline) accounting for 7.6% and indirect carbon flow (products, transportation, electricity) accounting for 92.4%. From the material flow perspective, the total carbon flow comprises product carbon flow (72.88%), resource and energy carbon flow (25.73%), transportation carbon flow (1.04%), waste carbon flow (0.35%), and service carbon flow (0.01%). In terms of activity scope, construction-related carbon flow accounts for 99.17%, while office and daily operations account for 0.46%. Two indicators, material consumption carbon flow rate and energy consumption carbon flow rate, are proposed for the first time. Comparative analysis of five girder bridges reveals that the Hejiawan Bridge has a material consumption carbon flow rate of 3.91 kg CO2eq/kg, ranking highest among similar bridges, while its energy consumption carbon flow rate is 13.40 kg CO2eq/kg ec, at a medium level. The assessment indicates relatively high material consumption, suggesting potential for carbon reduction through structural and geological optimization.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510084
The rapid expansion of lithium battery industries has elevated lithium resources to strategic importance, yet lithium extraction generates 8–10 tons of slag per ton of lithium salt, with complex heavy metal content and high leaching risks. This study improves conventional alkali activation by employing a composite activator and multi-stage thermal assistance to achieve self-solidification of lithium slag, simultaneously immobilizing multiple heavy metals while producing high-strength materials. Under full slag conditions, the mechanical strength of solidified materials ranged from 3.48 to 8.25 MPa; after optimization, strength increased by 137.07%. Average immobilization rates for various heavy metals rose from 97.26% to 99.77%. In simulated acidic, alkaline, neutral, high-salt, acid rain, and leachate environments, efficient immobilization was maintained, with leachate concentrations below regulatory limits. The improved activator and thermal process reduced structural defects, promoted formation of the key Si-O-Al framework, and ensured structural integrity, enhancing both mechanical strength and heavy metal immobilization. The cost of slag solidification was approximately 185–200 CNY per ton, significantly lower than conventional methods, with low energy consumption, no high-temperature calcination, and reduced equipment and reagent requirements, supporting scalability.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509080
Plastic pollution poses a global environmental challenge, and developing efficient, low-cost pyrolysis catalysts is crucial for resource recovery from plastic waste. This study investigates ex-situ catalytic pyrolysis of low-density polyethylene (LDPE) over ZSM-5 (Si/Al = 25) modified with Zn and Fe at loadings of 5% and 10% via impregnation. Catalysts were characterized by XRD, FT-IR, XPS, SEM, TEM, and BET. TGA was used to assess thermal behavior, and catalytic pyrolysis experiments were conducted in a tube furnace at 450 °C, with product analysis by GC-MS. Results show that metal incorporation preserved the ZSM-5 framework while modifying acid site distribution and surface morphology, enhancing cracking and dehydrogenation. All modified catalysts increased light gasoline-range hydrocarbon yield and reduced heavy fractions compared to non-catalytic runs. Among them, 10% Zn/ZSM-5 exhibited the best performance, boosting light gasoline hydrocarbons to 74.77%, approximately three times that of the non-catalytic case, significantly improving oil quality. This study demonstrates the potential of low-cost metal-modified zeolites for efficient and economical plastic waste pyrolysis.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510060
Wastewater treatment plant (WWTP) effluent is a significant pathway for emerging contaminants (ECs) to enter natural water bodies. This study investigated the removal of ECs by two field-scale gravel-based constructed wetlands: a horizontal subsurface flow constructed wetland (QL-CW) and a surface flow constructed wetland (BL-CW), both treating actual WWTP effluent. The influence of operation mode and wetland plant type on EC removal was examined. Using liquid chromatography-mass spectrometry, principal component analysis, and ecological risk assessment, the removal efficiencies and mechanisms for various ECs were explored. In QL-CW, biodegradation was more pronounced, particularly via ammonia-oxidizing bacteria co-metabolism, favoring ECs with benzyl, secondary amine, secondary amide, tertiary amide, halogenated, and carboxyl functional groups. In BL-CW, electrostatic attraction and hydrophobic interactions were more significant, with plant and root-microorganism uptake and adsorption playing key roles. Surface flow mode achieved significantly higher removal of antibiotics (45.3% vs. 34.1%) compared to horizontal subsurface flow, while no significant differences were observed for non-antibiotic pharmaceuticals (66.6% vs. 64.4%) and pesticides (49.8% vs. 34.2%). Planting Cyperus alternifolius (windmill grass) was more beneficial for antibiotic removal (43.6% vs. 30.1%) than planting Ipomoea aquatica (water spinach). The wetlands effectively reduced the ecological risks of most ECs to marginal levels. This study provides insights into the deep treatment of ECs in WWTP effluent by constructed wetlands.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607013
This study investigated the synergistic effects of earthworm mucus and two biochar types (rice husk biochar and straw biochar) on heavy metal bioavailability during sludge composting. Sludge was amended with earthworm mucus alone or combined with biochars at varying proportions, and the impacts on physicochemical properties, total heavy metal concentrations, bioavailable fractions, and chemical speciation were analyzed. Results showed that mucus addition increased sludge pH and electrical conductivity (EC) but decreased total nitrogen (TN) and total phosphorus (TP) contents. Synergistic mucus-biochar composting further elevated pH and EC while reducing TN, with the optimal treatment being mucus plus 10% rice husk biochar. Mucus-only composting reduced total concentrations and bioavailability of Cd, Cu, Ni, Zn, and Pb. Adding biochars significantly enhanced these reductions. Specifically, mucus with rice husk biochar achieved the best Cd removal, with total and bioavailable Cd decreasing by 27.03%–55.68% and 9.52%–28.57% (P<0.05), respectively, compared to controls. Mucus with straw biochar was most effective for Ni, Zn, and Pb, reducing total contents by 3.81%–5.72%, 7.93%–34.62%, and 42.61%–79.46%, and bioavailable fractions by 2.90%–26.31%, 15.58%–24.14%, and 32.30%–36.88% (P<0.05), respectively. Speciation analysis revealed that Cd, Ni, and Pb carbonate-bound fractions transformed into residual forms, and exchangeable fractions shifted to Fe-Mn oxide-bound forms. Straw biochar addition resulted in the highest residual fractions for Cd, Cu, Ni, Zn, and Pb, increasing by 0.35%–7.02%, 8.61%–12.90%, 16.62%–23.02%, 17.33%–26.10%, and 16.12%–27.20% (P<0.05), respectively. These findings demonstrate that earthworm mucus combined with rice husk or straw biochar effectively reduces heavy metal concentrations and bioavailability in sludge, offering a promising strategy for sludge composting.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3984-5
Rechargeable aluminum batteries (RABs) are promising for large-scale energy storage due to high theoretical capacity, inherent safety, and abundant aluminum reserves. However, conventional AlCl3-based ionic liquid electrolytes suffer from high cost, uncontrolled dendrite growth, and severe anode corrosion. Here, a molecular-level ligand engineering strategy is proposed, employing nitrogen-containing cyclic amides with tunable N–H functionalities to modulate the coordination environment of deep eutectic electrolytes (DEEs). Combined experimental and theoretical investigations reveal that the α-pyrrolidone-based DEE (PDEE) possesses a wider electrochemical window, higher ionic conductivity, and lower polarization. Precise N–H regulation optimizes cationic ligand and chloroaluminate anion interactions, accelerating ion transport to facilitate uniform Al deposition without dendrites. The amine functionalities enable in situ construction of a uniform inorganic-organic bilayer solid electrolyte interphase, mitigating anode corrosion and enhancing long-term interfacial stability. As a result, Al//Al symmetric batteries with PDEE achieve stable cycling for over 2000 hours, while Al-graphite full batteries demonstrate negligible capacity decay after 6000 cycles. This study establishes that ligand molecular engineering offers an effective strategy for optimizing DEEs, enabling durable and high-performance RABs.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3962-y
Photochromic Förster resonance energy transfer (pc-FRET)-based subnanometric polymersomes with accurate color control offer a transformative yet challenging tactic for advanced and custom-tailored information encryption. Herein, various amphiphilic alternating pyrene/azobenzene-containing copolymers were polymerized using one-pot Ugi four-component polycondensation. Subsequent self-assembly was performed to produce highly-integrated monolayer subnanometric polymersomes (MSNPSs) and their composites, with diameters of around ~250 nm and vesicular thicknesses of approximately ~12.0 Å. J-aggregated monolayer chain-folding mechanism was accountable for the donor-acceptor-donor stacking manner within the vesicular membrane, beneficial to achieve highly efficient energy transfer. The trans-to-cis photoisomerization of azobenzenes rendered MSNPSs and their composites with photo-triggered structural transitions in diameter and vesicular thickness. Benefitting from considerable spectral overlap between cis-azobenzene and pyrene, MSNPSs and their composites were capable of photo-controllable non-invasive pc-FRET performance with a wide Stokes shift (~320 nm). The accurate color variation from blue to red highly depended upon precise modulation of both irradiation duration and precursor-fixed donor/acceptor ratios. The proof-of-concept individually multichromatic 2D QR code was attained using photochromic MSNPSs and their composites in patterning lithography, displaying a multimodal decryption and favorable repeatability for high-level and personalized information protection. Our work paves a prospective avenue to meticulously craft stimuli-chromatic polymersomes for the potential of advanced information encryption.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202512059
Recovery of palladium from Pd-bearing wastewater is economically and environmentally significant. Adsorption is a promising method due to its simplicity, low cost, and high efficiency. In this study, a novel thiol-modified adsorbent (CHT-SH) was synthesized via one-step functionalization of inexpensive chitin (CHT) with thioglycolic acid. At room temperature and pH=2, CHT-SH exhibited an experimental adsorption capacity of 223.67 mg·g−1 for Pd(II), which was approximately 7 times higher than that of pristine CHT (30.6 mg·g−1). Kinetic and isotherm studies indicated that the adsorption process followed the pseudo-second-order kinetic model and the Langmuir isotherm model, with a maximum theoretical adsorption capacity of 248.89 mg·g−1, suggesting monolayer chemisorption. Characterization (FTIR, SEM, XPS, XRD) and density functional theory (DFT) calculations revealed that the adsorption mechanism primarily involved synergistic coordination of nitrogen and sulfur atoms, along with electrostatic interactions. Furthermore, CHT-SH demonstrated good reusability, retaining stable adsorption capacity after five adsorption-desorption cycles. Compared to other adsorbents that rely on redox mechanisms and are costly, CHT-SH offers comprehensive advantages. This work provides a cost-effective and efficient adsorbent for Pd(II) recovery from wastewater, offering technical support and theoretical reference for practical applications.