Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025010802
Ozone (O3) pollution is a prominent issue in the Guanzhong Plain, necessitating effective control of its precursors, particularly volatile organic compounds (VOCs). However, studies on VOC pollution characteristics at the county level are scarce. To investigate the summer VOC pollution characteristics and sources in high-altitude towns of the Guanzhong Plain, continuous monitoring of 53 typical VOC species was conducted at two sites in Changwu County, Xianyang City (elevation 1200 m). The spatiotemporal variations of ambient VOCs and their ozone formation potential (OFP) were analyzed, and source apportionment was performed using the Positive Matrix Factorization (PMF) model. Results showed that average total VOC (TVOCs) concentrations at the Changwu Government and Changwu Middle School sites were 60.04×10⁻⁹ and 83.28×10⁻⁹, respectively. Oxygenated VOCs (OVOCs) dominated, accounting for 55.14% and 62.91% of TVOCs, followed by alkenes, aromatic hydrocarbons, and halogenated hydrocarbons. Industrial sources contributed the most (43.2%) to VOC emissions in Changwu County, but site-specific differences were observed: the Government site was primarily influenced by solvent use (30.7%) and motor vehicles (19.1%), while the Middle School site was dominated by domestic sources (27.6%) and motor vehicles (20.0%). The average OFP values at the Government and Middle School sites were 258.84×10⁻⁹ and 378.04×10⁻⁹, respectively, with alkenes and OVOCs as the main contributors, originating from industrial emissions, solvent use, and biogenic sources. EKMA curves indicated that Changwu County was in a VOC-limited regime during the observation period, confirming the effectiveness of VOC control for ozone mitigation. These findings provide scientific guidance for local ozone management and offer a paradigm for precise ozone pollution control in county-level regions of the Guanzhong Plain.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606018
Swine wastewater, a high-strength organic effluent, offers a viable substrate for anaerobic biohydrogen production, aligning with clean energy recovery. This study compared hydrogen production in three anaerobic sequencing batch reactors (ASBRs) treating: raw wastewater (R1), supernatant after MAP (magnesium ammonium phosphate) precipitation for nitrogen and phosphorus recovery (R2), and the same supernatant with anaerobic sludge heat-treated at 75°C for 0.5 h (R3). Without pH adjustment, hydrogen production in R1 remained below 0.50 mmol/(kg·d). At an influent COD of 1800 mg/L, R2 and R3 achieved hydrogen production rates of 48.17 and 71.44 mmol/(kg·d), respectively. At COD 2400 mg/L, methane concentrations in R1, R2, and R3 were 10.8%, 14.2%, and 9.1%, respectively, indicating MAP pretreatment enhanced both hydrogen and methane production. As COD increased, R1's methane concentration rose to 14.6%, while average COD removal efficiencies for R1, R2, and R3 were 78.9%, 70.8%, and 52.5%, respectively. Under pH adjustment, all reactors peaked at pH 4.0, with hydrogen production rates of 0.10, 7.74, and 8.83 mol/(kg·d) for R1, R2, and R3, respectively. These findings demonstrate that MAP pretreatment combined with sludge heat treatment significantly enhances biohydrogen production, offering a promising strategy for swine wastewater valorization.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3851-3
Aqueous zinc-ion batteries (AZIBs) face critical challenges from zinc anode instability, including corrosion, hydrogen evolution reaction (HER), parasitic byproduct formation, and uncontrolled dendrite growth. To address these issues, we developed a multifunctional cerium-based metal-organic framework (Ce-MOF) coating for zinc anodes. The coating features an ordered porous structure and inherent properties that mitigate HER, suppress side reactions, and inhibit dendrite formation. Symmetric cells using Ce-MOF/Zn demonstrated exceptional cycling stability for over 2060 h at 0.5 mA cm−2 with a low hysteresis polarization of 26 mV. In full cells with an I2@AC cathode, the Ce-MOF/Zn||I2@AC achieved outstanding cycling stability of 28,550 cycles at 5 A g−1, with 91% capacity retention (109.6 mAh g−1). Through integrated characterization employing in-situ optical microscopy, ex-situ XRD, SEM, and DFT calculations, we elucidated the multifunctional mechanism: the Ce-MOF coating facilitates preferential (002)-oriented Zn deposition to suppress dendrites, reduces Zn2+ desolvation energy to enhance deposition kinetics, and modulates interfacial chemistry to mitigate HER and corrosion. This work establishes Ce-MOF coatings as a simple yet powerful strategy for developing high-performance zinc anodes, providing critical insights for advancing practical AZIB technologies.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3949-4
Sodium metal is considered an ideal anode material for high-performance sodium-based batteries. However, volume changes and dendrite growth during cycling seriously restrict its practical application. To address these challenges, this study utilizes harmful green tide algae Enteromorpha prolifera as a raw material to fabricate a self-supporting, sodiophilic, 3D Enteromorpha prolifera-derived carbon (EC) matrix via defect engineering. The results demonstrate that the 3D EC matrix can reduce nucleation overpotential, enhance binding ability with sodium atoms, and induce sodium to deposit horizontally inside EC, effectively addressing the issue of dendrite formation. Furthermore, the Na-EC symmetric cell demonstrates exceptional cycling stability with an ultralow polarization of 12 mV over 1000 h at 5 mA cm−2, 5 mA h cm−2. Notably, this stability persists even under ultrahigh current density and areal capacity conditions (30 mA cm−2, 30 mA h cm−2), maintaining stable operation for 500 h. When configured in full-cell systems with Na3V2(PO4)3 cathode, the assembled cell delivers an initial discharge capacity of 108.1 mA h g−1 at a 1 C rate, and maintains a capacity retention rate of 94.4% after 500 cycles. This study proposes an innovative strategy to advance high-performance dendrite-free sodium metal batteries through the recycling of marine environmental waste into functional energy materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4188-x
Sodium metal anodes, with high theoretical capacity (1166 mAh g−1) and low redox potential (−2.71 V vs. H+/H2), are promising for low-cost, high-energy sodium metal batteries (SMBs). However, uncontrolled dendrite growth and drastic volume changes cause short circuits and safety hazards. This work presents a dual-gradient engineering strategy to address these issues. A 3D self-supporting current collector (SSM-ZnS@Zn) was fabricated by laminating a stainless steel mesh (SSM) with a Zn foil decorated with pre-grown ZnS nanoparticles via a one-step rolling process. The substantial electrical conductivity difference between the bottom zinc foil (~16.6×10^6 S m−1) and the top SSM (~1.3×10^6 S m−1) establishes an electric field gradient. Simultaneously, a sodiophilicity gradient is created by electrochemically in-situ generated sodiophilic NaZn13 and Na2S on the bottom zinc foil, combined with the sodiophobic upper SSM layer. This dual-gradient synergy guides bottom-up sodium deposition, homogenizes current density and electric potential, and reinforces mechanical robustness. The framework exhibits outstanding electrochemical performance in both symmetric and full cells, outperforming most reported 3D structures. A pouch cell assembled with SSM-ZnS@Zn successfully lit an LED lamp, demonstrating practical application potential. This strategy surpasses single-gradient limitations and offers a new approach for high-performance sodium metal anode design.