SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4347-9
Overcoming the intrinsic loading ceiling of oxide-supported single-atom catalysts remains a long-standing challenge, because oxide frameworks generally provide limited capacity for accommodating high densities of isolated metal species. Here, we report a hollow TiO2 nanoreactor that effectively addresses the long-standing loading limitation of oxide-supported catalysts by coupling high-capacity ion exchange with structural confinement. The multiscale framework is derived from a sodium titanate hollow flower-sphere assembled from ultrathin nanosheets. It enables broad accessibility of exchange sites and facilitates high Cu uptake prior to oxide formation. Subsequently, during Ar-assisted transformation into oxygen-vacancy-rich TiO2, the incorporated Cu species remain highly dispersed within the framework, while vacancy-mediated metal–support interactions further enhance their stability. As a result, controllable Cu speciation is achieved at ultrahigh loadings of 7.4 wt% as spatially isolated single atoms and 12.4 wt% as single-atom/subnanometer-cluster hybrids. The optimized hybrid catalyst delivers a hydrogen evolution rate of 28.8 mmol g−1 h−1 under simulated sunlight, surpassing conventional low-loading Cu/TiO2 systems under comparable conditions. This strategy is readily extendable to other transition metals (Fe, Co, and Ni), establishing a structural design principle for constructing high-density and speciation-controlled metal sites on oxide supports.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4299-9
A dual-doping strategy incorporating boron (B) and sulfur (S) into graphitic carbon nitride (g-C3N4) was employed to engineer band structures and construct an S-scheme homojunction (BSCN) for enhanced photocatalytic hydrogen (H2) evolution. The BSCN catalyst exhibited an interwoven architecture of porous nanotubes and nanosheets, providing a large specific surface area and abundant active sites. In situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations revealed an S-scheme charge transfer mechanism at the BCN/SCN interface, driven by a built-in electric field that facilitates efficient spatial separation of photogenerated charge carriers. Photoelectrochemical measurements confirmed improved light harvesting and charge separation. DFT simulations indicated near-thermoneutral hydrogen adsorption free energy (ΔGH* = 0.12 eV) at S-doped sites, favorable for hydrogen evolution reaction (HER) kinetics. The optimized BSCN achieved an exceptional H2 evolution rate of 14.409 mmol g−1 h−1, approximately 75-fold and 3.4-fold higher than pristine BCN and SCN, respectively. This work establishes a rational doping-mediated approach for designing high-efficiency g-C3N4 homojunctions and provides mechanistic insights into S-scheme charge transfer for solar-driven H2 production.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4232-1
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.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3657-9
Perovskite/silicon tandem solar cells (TSCs) have achieved power conversion efficiencies (PCE) up to 34.9%, surpassing the Shockley-Queisser limit of single-junction devices. The interconnection layer (ICL) critically bridges top and bottom subcells, enabling charge carrier recombination. Conventional indium oxide (In2O3)-based TCOs suffer from high-energy ion bombardment during sputtering, damaging amorphous silicon subcells and reducing open-circuit voltage (VOC) and fill factor (FF). Additionally, indium scarcity and cost necessitate indium-free alternatives. Here, we introduce a highly degenerate indium-free samarium-doped cadmium oxide (CdO:Sm) TCO as the ICL for perovskite/SHJ TSCs, deposited via low-damage reactive plasma deposition (RPD). The ultrathin CdO:Sm film (~3 nm) exhibits average transmittance of 85% (400–1200 nm) and 90% (800–1200 nm), enabling efficient near-infrared absorption in the bottom subcell. High doping concentration and mobility ensure excellent electrical conductivity. The low work function (4.04 eV) of CdO:Sm facilitates carrier tunneling and efficient recombination. Devices employing CdO:Sm ICL achieved approximately 1% higher efficiency compared to those with indium-based TCO ICLs. Detailed characterization including contact resistivity (1.68 mΩ cm2), conductive atomic force microscopy, Kelvin probe force microscopy, and photoluminescence quenching confirm enhanced carrier transport and extraction. This work demonstrates a viable indium-free ICL for high-efficiency perovskite/SHJ TSCs, addressing both performance and sustainability challenges.
New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61072-4
Sodium-ion capacitors (SICs) typically feature a hybrid design, incorporating a battery-type anode that operates by faradaic redox reactions and an activated carbon cathode that functions through electrical double-layer (EDL) adsorption/desorption. However, the kinetics of faradaic processes are inherently slower than those of EDL processes, leading to a fundamental problem known as kinetic imbalance between the electrodes, which hinders the development of high-performance SICs. To address this, we synthesized composites of bismuth nanoparticles in N-doped carbon (Bi@NC) by a high-temperature sintering method. The resulting Bi@NC anode has a specific capacity of 300 mAh g−1 at 0.5 A g−1, an exceptional rate capability (maintaining performance at currents exceeding 75 A g−1), and outstanding cycling stability over 12,000 cycles. Three-electrode Swagelok cell tests revealed that this high-rate Bi@NC composite effectively decreases the kinetic gap with the activated carbon cathode, as shown by an analysis of their respective potential swing windows (vs. Na/Na+). This enables the fabricated SIC to achieve a maximum energy density of 115 Wh kg−1, a peak power density of 45,535 W kg−1, and a long cycle life exceeding 8,000 cycles.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024112102
Based on the 2022 activity data of non-road mobile sources in Hebei Province, this study employed the emission factor method recommended by the Guidelines to estimate emissions of CO, HC, NOx, PM2.5, PM10, and SO2. A comprehensive emission inventory was established, followed by spatial and uncertainty analyses. Scenario analysis, aligned with the 14th Five-Year Plan policies, was used to project emissions for 2030. The results indicate that non-road mobile sources in Hebei emitted 76.1×10^3 t of CO, 20.6×10^3 t of HC, 164.0×10^3 t of NOx, 8.5×10^3 t of PM2.5, 9.0×10^3 t of PM10, and 2.4×10^3 t of SO2. Agricultural machinery was the dominant contributor to CO, HC, PM2.5, and PM10, accounting for over 60.0% of CO emissions. Railway locomotives were the primary source of NOx, contributing 50.9%. For SO2, agricultural machinery and railway locomotives contributed 39.0% and 44.4%, respectively. The highest emitting cities were Tangshan (21.3%), Shijiazhuang (15.7%), Cangzhou (11.6%), and Handan (11.6%). Ship emissions were concentrated in Tangshan Port; civil aviation emissions were mainly in Shijiazhuang, Tangshan, Qinhuangdao, and Handan; railway emissions were distributed in Shijiazhuang, Baoding, and Handan. Under the updated emission standard scenario, NOx and PM10 emissions in 2030 could be reduced by approximately 35.0%. The phase-out of old machinery yielded the largest reduction in CO (36.0%), while both electrification and phase-out scenarios significantly impacted HC emissions.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604006
High-strength sulfamethoxazole (SMX) wastewater severely inhibits anaerobic microorganisms, reducing organic degradation and methane yield. This study investigated the effects of short-chain (C6-HSL) and long-chain (C12-HSL) N-acyl-homoserine lactone (AHL) signaling molecules, individually and in combination, on the construction, performance, and antibiotic resistance gene (ARG) profiles of anaerobic electroactive biofilms within a microbial electrolysis cell coupled anaerobic digestion (MEC-AD) system. Compared to the control (no AHLs), SMX removal efficiency increased by 9.26%, 7.44%, and 10.67% for C6-HSL (T1), C12-HSL (T2), and combined (T3) treatments, respectively. Methane production rates rose by 20.4%, 16.9%, and 23.1% for T1, T2, and T3, respectively. AHLs promoted extracellular polymeric substance secretion, enhancing electroactive microbe attachment to the anode. Microbial community analysis revealed increased diversity and modulated key functional genera. Notably, Georgenia abundance increased by 16.77% (T1) and 36.47% (T3) but decreased by 15.99% (T2). ARG analysis showed that single AHLs elevated intI1, sul1, and sul2 abundances, whereas combined AHLs (T3) exhibited a milder response, with sul2 abundance reduced by 4.92% relative to control. This suggests synergistic AHLs suppress ARG host proliferation. This study first demonstrates that combined short- and long-chain AHLs enhance electroactive biofilm formation, maintain microbial community stability, and modulate ARG dissemination risk, offering a quorum sensing-based strategy for antibiotic wastewater treatment and risk management.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604010
Guar gum production wastewater contains 1,2-propanediol, which in conventional anaerobic treatment causes propionate accumulation and microbial inhibition. Microaerobic conditions foster fermentative bacterial metabolism, enhancing organic substrate conversion, while biochar promotes anaerobic microbial aggregation and oxygen tolerance. This study treated actual guar gum wastewater using three configurations: blank control, anaerobic, and microaerobic-biochar (O2/BC) coupled systems. Under mesophilic conditions (37 °C), with micro-aeration at 0.2 mL/(g VS·d) and biochar dosage of 15 g/L, the O2/BC system achieved a COD removal efficiency of 90%, 10.6 percentage points higher than the anaerobic control. Effluent COD and propionate concentrations dropped to 3800 mg/L and 0.15 g/L, respectively, representing reductions of 49.6% and 98.4% versus the control. Biogas production was 1.64 times that of the control, with a maximum methane concentration of 77.2%. Fourier transform infrared spectroscopy (FT-IR) indicated increased abundance of –OH, –CH2–, and C–O functional groups on sludge surfaces, revealing biochar's adsorption enhancement. Scanning electron microscopy (SEM) showed dense microbial aggregates dominated by long bacilli, distinct from conventional anaerobic sludge. Microbial community analysis revealed increased abundance of Clostridium and Comamonas, modulating the propionate-to-acetate ratio and optimizing acidification efficiency, thereby promoting complex organic degradation. This study provides a novel technical pathway for biological treatment of alcohol-rich organic wastewater.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604022
The resource utilization of food waste contributes to reducing environmental pollution, driving nutrient cycling and biomass energy development, and promoting the resource recycling industry, achieving a win-win outcome for environment and economy. This study evaluated the resource recovery performance and environmental impacts of producing carbon sources for wastewater treatment through hydrolysis and acidification of food waste, comparing with two conventional alternatives: anaerobic fermentation and incineration. Results showed that among the three technologies, hydrolysis for carbon source production ranked middle in resource recycling efficiency, but its environmental benefits were superior to incineration and anaerobic fermentation. The hydrolysis process did not produce additional wastewater requiring treatment, and its greenhouse gas emissions and solid waste generation intensity were relatively low, at -40.7 kg CO2-eq/t and 9.3%, respectively. Carbon sources derived from food waste can replace commercial alternatives, reducing wastewater treatment costs and promoting synergies between pollution reduction and carbon mitigation. Sensitivity analysis revealed that water content in food waste significantly influences solid impurity generation and energy recovery efficiency of hydrolysis technology. In regions with high food waste generation and carbon source demand, hydrolysis technology is recommended to facilitate large-scale synergistic treatment of wastewater and food waste.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511002
To treat large-air-volume, low-concentration volatile organic compounds (VOCs) containing tetrachloroethylene (PCE) generated from rubber-metal bonding, this study systematically investigated the adsorption-desorption behavior and interaction mechanisms of PCE, toluene, and methyl isobutyl ketone (MIBK) on granular activated carbon (GAC). Static adsorption experiments showed that PCE adsorption capacity reached 556.6 mg·g−1, while dynamic multi-component adsorption capacity was 179.6 mg·g−1. Kinetic analysis indicated that PCE adsorption was controlled by both intraparticle diffusion and external surface adsorption, whereas toluene and MIBK were primarily intraparticle diffusion-limited. During high-temperature nitrogen desorption, PCE underwent dechlorination, hydrogenation, and recombination, producing trichloroethylene, 1,2-dichloroethane, 1,2-dichloropropane, and HCl, with HCl accounting for 3.61% of the chlorine molar content in adsorbed PCE. After four adsorption-desorption cycles, the iodine value of GAC dropped below the industry standard of 600 mg·g−1; however, water washing and alkali immersion extended the cycle life to 8 and 9 cycles, respectively. The HCl generation pattern in co-adsorption systems was consistent with single-PCE systems. A regeneration process combining alkali immersion and water washing was proposed and integrated into an engineering strategy. Compared to conventional activated carbon adsorption coupled with RTO incineration, the proposed classification strategy reduced annual costs by 49.5×10⁴ CNY. This work provides a cost-effective and safe solution for Cl-VOCs treatment.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3909-0
Perovskite solar cells (PSCs) are leading candidates in third-generation photovoltaics, yet achieving uniform crystallization from top to buried interfaces remains critical for high efficiency and stability. The buried interface is particularly challenging due to substrate-induced nucleation suppression and spatial confinement, leading to disordered crystallization, small grains, and high defect densities. Residual strain from thermal expansion mismatch further exacerbates defect formation and non-radiative recombination. Existing strategies, such as heterogeneous nucleation sites or pre-deposited 2D perovskite seeds, often fail because these layers are washed away or dissolved during subsequent processing, compromising structural integrity and reproducibility. In a recent breakthrough, Chen et al. (2025) reported the construction of stable buried 2D perovskites using specially designed organic spacer cations: 2,3-dihydroisoindole hydroiodide (DHIII) and 4,5,6,7-tetrahydrothieno[3,2-c]pyridine hydroiodide (ThPyI). Unlike conventional spacers like phenethylammonium (PEA) and 2-thiophenemethylammonium (ThMA), DHIII and ThPyI induce spontaneous formation of 2D perovskites that remain stable during subsequent spin-coating and annealing. This buried 2D structure effectively templates the growth of high-quality 3D perovskites, improving crystallization uniformity and passivating defects. The work demonstrates a viable route to overcome the long-standing challenge of stabilizing 2D phases at the buried interface, potentially enabling more efficient and stable PSCs.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4035-5
Electrocatalytic CO2 reduction reaction (CO2RR) to formate offers a promising pathway for storing renewable electricity in chemical fuels and enabling carbon recycling. The development of efficient and stable catalysts for this specific pathway, however, remains a central challenge. Heteroatom doping can significantly tune the interaction between active sites and key intermediates, boosting catalytic performance. Conventional doping in Bi-based catalysts often relies on uncontrollable in-situ electrochemical processes, leading to ineffective bulk incorporation. Here, we present a simple pre-doping strategy that enables precise doping at surface active sites, thereby enhancing electrochemical performance. The resulting catalyst achieves >95% Faradaic efficiency for formate across 100–500 mA cm−2 in a flow cell and maintains >95% efficiency for over 70 h at 100 mA cm−2 in a membrane electrode assembly, outperforming pure Bi and Bi2S3. A solar-driven system further demonstrates a 4.4% solar-to-formate conversion efficiency. Mechanistic studies reveal that sulfur doping increases electron density, stabilizes the key *OCHO intermediate, and suppresses hydrogen evolution. These findings provide valuable insights into the precise pre-doping modulation of surface active sites for designing highly efficient and stable CO2RR catalysts.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4132-y
Manganese-iron-based mixed polyanionic cathodes are promising for sodium-ion batteries (SIBs) due to high energy density and operating voltage, but suffer from Jahn-Teller distortion of Mn3+ that degrades cycling stability. Here, a structural modulation strategy via Mg2+ doping is reported. Electrochemically inert Mg2+ forms stronger chemical bonds, adjusts lattice parameters, and suppresses Jahn-Teller distortion, enhancing structural stability. Mg2+ also widens sodium-ion diffusion channels, improving diffusion kinetics. Additionally, an in-situ three-dimensional carbon nanotube (CNT) conductive network boosts electronic conductivity. The resulting NFMPP-Mg@CNTs cathode delivers a discharge capacity of 126 mAh g−1 at 0.1 C (near theoretical 129 mAh g−1), retains 80% capacity after 3000 cycles at 0.5 C, and achieves an energy density of 401 Wh kg−1, among the highest reported for mixed phosphate systems. Ex-situ XPS and first-principles calculations confirm that Mg2+ resists geometric distortion by enhancing lattice stability and widening Na+ diffusion pathways (migration barrier reduced from 0.566 to 0.398 eV). This work provides a viable route for high-energy, long-life SIB cathodes suitable for large-scale energy storage.