Rational design of photoelectric active materials for photoanodes in photocatalytic fuel cells is crucial for developing highly sensitive self-powered electrochemical sensors. Achieving directional migration and shortening transmission pathways of charge in photoanodes remains a fundamental challenge for enhancing the oxygen evolution reaction performance of photocatalytic fuel cells. Herein, tungsten species atomically dispersed on carbon-rich graphitic carbon nitride (W-CN-C) with the N–W–O covalent bond was designed as the photoanode for constructing a self-powered photocatalytic fuel cell sensing of heavy metal copper ions. W-CN-C was synthesized by self-assembly, exfoliation, and thermal-induced treatment process. The N–W–O covalent bonds by anchoring tungsten atoms on carbon-rich carbon nitride served as an interfacial charge transport channel, facilitating the separation and migration of charge carriers. The carbon content increase by forming a carbon-rich structure can enhance π-electron delocalization in the W-CN-C, significantly broadening sunlight utilization range. The dispersed tungsten atoms provide effectively active sites, promoting the kinetics of the oxygen evolution reaction between the W-CN-C photoanode and electrolyte interface. The synergistic effects significantly enhance the visible light absorption ability and charge separation and transfer efficiency, improving the photoelectric conversion efficiency of W-CN-C photoanode, exhibiting superior oxygen evolution reaction performance, leading to the amplified open circuit potential in the photocatalytic fuel cell system based on excellent oxygen reduction reaction performance of the Pt@C electrocatalyst cathode. The specific identification probe for copper ions was effectively anchored on the W-CN-C photoanode to construct a self-powered photocatalytic fuel cell sensing platform for copper ions detection. The complex formed by copper ions and the probe hindered electron transport at the W-CN-C photoanode, altering the output detection signal of the photocatalytic fuel cell, thus demonstrating a broad detection range spanning five orders of magnitude (2.0 × 10⁻²–9.2 × 10² nmol L⁻¹), a low limit of detection (7.0 pmol L⁻¹), high selectivity against common interferents, and applicability for detecting heavy metal copper ions in the aquatic environment. Furthermore, the platform allowed for self-powered and portable determination of copper ions using a multimeter as a signal output device, achieving a detection range of 0.25–1.3 × 10² nmol L⁻¹ and a limit of 84 pmol L⁻¹. This work proposes an approach for developing a high-performance photoanode utilizing atomically dispersed metals to introduce covalent bonds as charge transfer channels, paving the way for highly sensitive self-powered electrochemical sensors for environmental monitoring.

Hard carbon (HC) derived from corn-distillers is a sustainable, affordable anode candidate for sodium-ion batteries (SIBs), yet its practical deployment has been limited by insufficient reversible capacity. Here we report a temperature-gradient treatment that precisely tailors interlayer spacing, porosity, and graphitization in corn-distillers-derived hard carbon, unlocking exceptional electrochemical performance. The optimized material exhibits an interlayer spacing of 0.378 nm and a dominant pore size of 1.68 nm. It demonstrates outstanding high-rate behavior, achieving 289 and 198 mAh g^-1 at 1.0 and 2.0 A g^-1, respectively. Additionally, it retains 83% of its capacity after 700 cycles at 2.0 A g^-1. Integrating in situ X-ray diffraction with ex situ Raman spectroscopy demonstrates a unique sodium-storage mechanism characterized by both "adsorption–intercalation and pore-filling". This approach helps elucidate the rapid kinetics and long-lasting performance. These results demonstrate that controlled structural tactics of biomass-derived HC can achieve the desired capacity, rate capability, and longevity required for practical SIB anodes—bringing an abundant, waste-derived feedstock dramatically closer to commercialization.

Amidst growing concerns regarding pesticide contamination, particularly within the realms of food, grains, and meat products, the quest for highly efficient and stable photocatalysts for pollutant degradation has become an imperative area of research. In this study, a novel S-scheme heterojunction photocatalyst, Al₆Si₂O₁₃/BiOBr (ASO/BO) nanocomposites, was successfully synthesized to enhance charge transfer and improve the photocatalytic degradation of Triazophos (TAP) and Dichlorvos (DDVP), prevalent agricultural pollutants. Performance evaluation revealed that the 60-ASO/BO nanocomposite (with 60% ASO loading ratio) achieved a remarkable degradation efficiency, reducing pesticide (TAP) concentration from 100% to 28.0% within 100 min, while retaining 94.7% of its initial activity after four cycles (400 min). In stark contrast, the degradation efficiencies of the individual ASO and BO were substantially lower, with ASO achieving 56.6% and BO merely 58.8%. For DDVP, the composite also exhibited excellent photocatalytic degradation activity, reducing its concentration from 100% to 32.3% within 100 min, far outperforming ASO (100% to 67.8%) and BO (100% to 47.9%). Enhanced charge migration within the S-scheme heterojunction accounts for the remarkable catalytic efficiency. The charge transfer pathway and mechanism were further validated using femtosecond transient absorption spectroscopy (fs-TAS), adsorption energy calculations, differential charge density analysis, Kelvin probe force microscopy (KPFM), and in situ X-ray photoelectron spectroscopy (XPS). The results emphasize that S-scheme charge migration is vital for enhancing photocatalytic performance. Consequently, the ASO/BO heterojunction based on the S-scheme provides a robust and reliable route for achieving durable and efficient photocatalytic removal of environmental contaminants, with broad application prospects in agriculture, food safety, and the preservation of grain and meat products.

The rational design of efficient step-scheme (S-scheme) heterojunctions is a significant breakthrough in photocatalysis, holding great potential to enhance eco-friendly environmental restoration and energy conversion technologies. However, conventional S-scheme heterojunctions frequently suffer from lattice mismatch issues, which severely compromise the efficacy of built-in electric fields in charge separation. To address this limitation, we developed an innovative in situ deposition strategy to construct van der Waals S-scheme heterojunctions within Bi₂O₂S-BiOBr composites. This approach effectively mitigates lattice mismatch and ensures intimate interfacial contact, enabling the formation of a strong internal electric field that facilitates efficient carrier migration. The Bi₂O₂S-BiOBr composites exhibit an extended light absorption range exceeding 700 nm, allowing for broad-spectrum photocatalytic activity. Under Xenon lamp irradiation, the Bi₂O₂S-BiOBr composites demonstrated outstanding photocatalytic efficiency in the degradation of ciprofloxacin (CIP). Notably, the 20%Bi₂O₂S-BiOBr composite achieved 93% CIP removal within 15 min, outperforming all other tested composites. The notable enhancement in performance stems from the van der Waals S-scheme heterojunction, which facilitates highly efficient separation of photogenerated carriers. This work provides valuable insights for the strategic design of advanced van der Waals heterostructures with S-scheme charge transfer mechanisms.

Lithium ferrate Li₅FeO₄ is a promising cathode prelithiation additive for lithium-ion batteries, boasting a high theoretical capacity of 867 mAh g⁻¹, which compensates for lithium loss due to solid electrolyte interphase (SEI) formation during the initial cycle. However, its practical application faces significant challenges due to inherent chemical instability. The material is extremely sensitive to air, readily undergoing deleterious side reactions with atmospheric carbon dioxide and moisture to form electrochemically inert Li₂CO₃ surface layers. This degradation in the atmosphere presents several major issues. It not only substantially reduces active lithium content but also induces severe slurry gelation during electrode manufacturing. In addition, it promotes continuous gas generation and electrolyte decomposition during battery operation, and leads to a significant increase in electrochemical impedance. Previous stabilization attempts via carbon coating or metal doping have shown limited success, often introducing new problems such as capacity reduction or inadequate protection, highlighting the urgent need for a more comprehensive and effective modification method. To address these challenges, this study proposes an efficient Lewis acid-induced regeneration strategy through thermal modification with PF₅. This approach effectively removes surface inert impurities and facilitates the in-situ construction of a composite layer of Li₃PO₄ and LiF on the Li₅FeO₄ particles. The regenerated Li₅FeO₄ exhibits excellent dispersion, air stability, and electrolyte interfacial compatibility, effectively suppressing slurry gelation and interfacial side reactions. In comparison with the bare counterpart, the regenerated Li₅FeO₄ shows a significantly reduced viscosity upon slurry processing and gas generation during high-temperature storage. When 1.5% (wt) regenerated Li₅FeO₄ is introduced to the LiFePO₄ cathode in the full cells, the cathode maintains a high capacity of 135.0 mAh g⁻¹ and a retention rate of 95.3% after 200 cycles. In contrast, the control LiFePO₄ cathode without Li₅FeO₄ only retains 113.7 mAh g⁻¹ with a capacity retention of 92.2%. This approach integrates impurity removal, interfacial stabilization, and performance enhancement of Li₅FeO₄ into one strategy, which will find extensive applications in long-cycle lithium-ion batteries.

Cathode materials play a critical role in determining the energy density, cycle life, and cost-effectiveness of sodium-ion batteries (SIBs). Among various candidates, P2-type layered oxide cathodes exhibit superior high-rate charge/discharge performance due to their open Na⁺ diffusion channels, making them particularly suitable for applications requiring rapid power delivery, such as starter batteries and grid frequency regulation. However, while the conventional P2-type Na_0.67Ni_0.33Mn_0.67O₂ (P2-NNMO) cathode demonstrates high energy density, the strong O²⁻–O²⁻ electrostatic repulsion within the transition metal layer during high-voltage charging induces an irreversible P2 → O2 phase transition accompanied by approximately 20% volume strain. This results in severe lattice distortion and structural collapse. Additionally, oxygen oxidation at high voltages contributes to charge compensation, reducing electrochemical reaction reversibility and accelerating structural degradation. Consequently, the P2-NNMO cathode suffers from rapid capacity decay and poor cycling stability, hindering its practical application. To overcome these challenges, we developed a multi-element doping strategy to design a P2-Na_0.67Zn_0.05Ni_0.23Fe_0.1Mn_0.57Ti_0.05O₂ (P2-NZNFMTO) layered oxide cathode. The synergistic doping of Zn²⁺, Ti⁴⁺, and Fe³⁺ enables concurrent optimization of structural and electrochemical properties. Specifically, Zn²⁺ doping enhances the O²⁻–Na⁺–O²⁻ electrostatic interaction, promoting the formation of local "Na⁺ pillars" within the Na layer to mitigate volume variation and phase transitions during cycling. Ti⁴⁺ doping disrupts Na⁺/vacancy ordering, significantly improving Na⁺ diffusion kinetics. The incorporation of Zn²⁺, Ti⁴⁺, and Fe³⁺ also alleviates the Jahn-Teller distortion associated with Ni²⁺/Ni³⁺, enhancing cycling performance while reducing material costs. The P2-NZNFMTO cathode exhibits exceptional electrochemical performance, demonstrating 96.7% capacity retention after 100 cycles at 1C rate with a high cut-off voltage of 4.3 V. Even at a high rate of 3C, it maintains over 85% capacity retention after 300 cycles. In-situ X-ray diffraction (XRD) and galvanostatic intermittent titration technique (GITT) analyses confirm its excellent structural stability and rapid Na⁺ transport capability at high voltages. This multi-element synergistic doping strategy establishes a novel design principle and theoretical foundation for developing high-voltage, long-cycle-life, and high-power SIB cathodes.

Hydrogen peroxide (H₂O₂) is widely utilised as a green chemical across numerous industries. Photocatalytic synthesis of H₂O₂ represents a highly promising green synthetic pathway. However, the application of single semiconductors is constrained by limitations in photogenerated charge separation and low photocatalytic reaction efficiency. Constructing heterojunctions to enhance interfacial electron transfer and improve charge separation is crucial for enhancing photocatalytic activity. Here, a two-step approach is employed to construct a Type-Ⅱ heterojunction ZnIn₂S₄/SCN, forming a directional and high-speed e^-/h⁺ transport channel. The built-in electric field (BEF) provides the driving force for the transport and separation of e^-/h⁺ at the interface. Thanks to a well-designed interface, the high recombination rate of photo-generated electron-hole pairs within a single photocatalyst and its relatively low photocatalytic activity have been effectively overcome. The ZnIn₂S₄/SCN heterojunction achieves a hydrogen peroxide yield of 257.0 μmol g^-1 h^-1 under air conditions via the oxygen reduction reaction (ORR) mechanism in pure water medium, realising highly efficient photocatalytic H₂O₂ synthesis. Based on a heterojunction design, this study provides an important reference for the highly efficient photocatalytic synthesis of hydrogen peroxide.

Multicomponent interface engineering based on metal-organic framework (MOF) derivatives holds great potential for achieving high-performance electromagnetic wave (EMW) absorption. However, precisely controlling heterointerface configurations and their associated polarization mechanisms remains a significant scientific and technical hurdle. In this study, a controlled pyrolysis-selenization strategy based on bimetallic MOF precursors was developed to prepare ZnSe/Cu₂Se multiphase composites. The rational engineering of precursor architecture and selenization degree achieves precise dual-control over morphology and heterointerfaces. Multiscale characterization, finite element simulations, and density functional theory (DFT) calculations collectively demonstrate that Cu₂Se forms an efficient conductive network within the carbon framework, leading to significant conductive loss. Simultaneously, the coexistence of the two metallic selenides creates numerous heterointerfaces which greatly enhance interfacial polarization losses. Additionally, defect-induced and dipole polarizations generate active sites that dissipate EMW through multiscale polarization synergy. Ultimately, the optimized composite exhibits outstanding EMW absorption performance, with a minimum reflection loss (RL_min) of −52.63 dB and a maximum effective absorption bandwidth (EAB_max) of 8.64 GHz. This study introduces a precise strategy for engineering heterointerfaces in MOF-derived bimetallic selenides, offering fundamental insights into the multiscale polarization synergy crucial for efficient EMW attenuation.