Huijie Hou

N-acyl-homoserine lactone-mediated quorum sensing can regulate biofilm formation and microbial metabolism, but its effects on concurrent electricity generation and nitrogen removal in bioelectrochemical systems remain unclear. Here, we examined the responses of single-chamber air-cathode microbial fuel cells (MFCs) to exogenous N-hexanoyl-DL-homoserine lactone (C6-HSL; 10 and 20 μM). Both treatments accelerated voltage stabilization, prolonged the stable-output period and improved electrical electron recovery. Maximum power density increased from 50.05 mW/m2 in the control to 59.90 and 55.46 mW/m2 at 10 and 20 μM, respectively. These changes coincided with greater anodic extracellular polymeric substance (EPS) contents, lower fitted biofilm resistance and enrichment of Burkholderiaceae. In contrast, C6-HSL impaired nitrogen removal. At an initial NH4Cl concentration of 0.5 g/L, total nitrogen removal after 48 h decreased from 94.24 ± 1.50% (control) to 80.66 ± 1.06% (10 μM) and 73.31 ± 2.01% (20 μM). Higher residual NH4+-N and NO2--N concentrations, together with lower cathodic amoA and nirS gene abundances, were consistent with impaired nitrogen transformation. An electron-equivalent comparison revealed increased electrical electron recovery alongside a lower stoichiometric electron requirement associated with observed nitrogen removal; it did not establish a causal diversion of electrons. Collectively, the findings identify contrasting electrogenic and nitrogen-removal responses to C6-HSL and underscore the need to evaluate both functions when applying quorum-sensing-based regulation in MFCs.

The rapid deployment of perovskite solar modules (PSMs) raises an urgent need for recycling strategies that can selectively recover critical metals from their complex multilayer architectures. Here, an architecture‐guided sequential recycling strategy is developed by coupling interfacial accessibility with calcination‐induced phase transformation. Ultrasonic water leaching removes >99.8% of Pb from the perovskite layer without detectable dissolution of other target metals. During subsequent HCl leaching, the polymer encapsulant functions as a physical barrier, enabling >99.9% In leaching while protecting the Sn‐coated Cu ribbon from acid attack. Air calcination then removes the encapsulant and promotes the formation of CuO and chemically stable SnO ₂ , creating a strong contrast in leaching behavior that enables selective Cu dissolution in an acetic acid‐hydrogen peroxide system. Overall, recovery ratios of In and Cu exceed 99.7% and 96.1%, respectively, while most of the initial Sn is retained in a Sn‐rich residue. The process further achieves a net economic benefit of about 4.735 USD/m ² module, demonstrating an economically promising and architecture‐enabled route for selective multi‐metal recovery from discarded industrial PSMs.

Electrochemical two-electron oxygen reduction (2e− ORR) provides a decentralized route for hydrogen peroxide (H2O2) production, yet rational tailoring of MOF-derived electrocatalysts remains challenging because carbonization entails substantial structural reorganization. Here, we report a precursor-substituent-induced pyrolytic reconstruction strategy to regulate the carbon microenvironment and interfacial electronic properties of Ni-MOF-derived electrocatalysts for selective H2O2 electrosynthesis. Using terephthalate-based Ni-MOF-X (X = H, NH2, NO2, or OH) precursors, we show that the strongly electron-withdrawing nitro substituent is associated with anisotropic fragmentation, high mesoporous accessibility, and pronounced carbon-lattice disorder after pyrolysis. Spectroscopic analyses establish an ensemble dominated by metallic Ni nanoparticles within an N/O-enriched polar carbon environment, rather than a uniquely defined first-shell Ni-N/O coordination structure. In a gas-diffusion flow cell, it reaches an H2O2 yield rate of 6.77 mol g−1 h−1 and sustains approximately 95% Faradaic efficiency over 100 h in 1.0 M KOH. Idealized descriptor-model calculations indicate that an N/O-polarized microenvironment shifts *OOH adsorption toward a more favorable energetic range, consistent with the experimentally observed kinetic and selectivity trends. These results establish precursor substituent chemistry as an effective means of directing pyrolytic reconstruction in MOF-derived electrocatalysts.

Efficient photocatalytic mineralization of volatile organic compounds (VOCs) is fundamentally constrained by limited visible‐light harvesting, rapid charge recombination, and high kinetic barriers associated with aromatic ring cleavage. Herein, it is reported that a Mo‐doped TiO ₂ /Sb ₂ S ₃ nanotube (Mo‐TiO ₂ /Sb ₂ S ₃ ) S‐scheme heterojunction in which dopant‐induced electronic modulation and interfacial built‐in electric field (BIEF) engineering operate cooperatively to enable directional charge transport and accelerated oxidation kinetics. Mo incorporation increases the TiO ₂ work function and amplifies the Fermi‐level offset relative to Sb ₂ S ₃ , generating a strengthened BIEF that promotes S‐scheme charge transfer while preserving strong redox potentials. Spectroscopic and photoelectrochemical analyses reveal prolonged carrier lifetime, enhanced interfacial charge mobility, and the formation of Ti‐S and Mo‐S covalent pathways that facilitate rapid electron flow and reactive oxygen species (ROS) generation. Density functional theory (DFT) calculations further demonstrates that Mo doping downshifts the d‐band center, strengthens reactant adsorption, and significantly lowers the energy barrier for benzoic acid ring‐opening, the rate‐determining step in toluene mineralization. As a result, the optimized catalyst achieves nearly complete toluene degradation with high CO ₂ selectivity under visible light. This work establishes a synergistic strategy combining dopant‐induced electronic tuning and S‐scheme heterointerface design to overcome kinetic bottlenecks in aromatic VOC mineralization, offering a pathway for advanced air purification.

Bipolar electrochemistry, which induces polarization in conductive materials, offers a promising yet mechanistically unresolved strategy for enhancing anaerobic digestion (AD). In study, a fixed bipolar electrode-coupled anaerobic digestion (BPE-AD) system was constructed to investigate how field-induced bipolar interfaces affect microbial community assembly and interspecies electron-transfer processes. The results support the proposed role of polarized conductive materials as field-induced third electrode interfaces that promote polarity-associated microbiome restructuring and enhance electron-transfer potential. With sodium acetate as substrate, the BPE reactor increased cumulative methane production by 182.6% to 142.49 ± 3.98 mL, and maintained methane content >79.9%. Using waste sludge, BPE-AD enhanced the release of soluble organics and increased methane yield by 30.1% compared to the traditional AD system. Electrochemical and microbial community analyses demonstrated that the bipolar electrodes not only improved the electrocatalytic activity of the driving electrodes but also developed convergent anodic and cathodic biofilm communities that mirrored those on the primary anode and cathode, respectively. This convergence led to the specific enrichment of electroactive genera (e.g., Geobacter) and methanogens (e.g., Methanobacterium) across the polarized network. Metagenomic prediction further indicated a systematic upregulation of genes encoding key enzymes for both hydrogenotrophic and acetoclastic methanogenesis pathways. The findings shift the paradigm from viewing conductive materials merely as passive enhancers to recognizing them as field-induced, functionally polarized electrodes that create dual-anode/cathode microenvironments to channel electron flux. These findings suggest that fixed bipolar electrodes provide a spatially organized electroactive interface for enhancing anaerobic digestion, offering a mechanistic basis for designing next-generation bioelectrochemical AD systems.

Efficient delamination of cathode active materials from aluminum current collectors is a critical pretreatment step in recycling spent lithium-ion batteries. Here, a phosphate-based alkaline deep eutectic solvent (DES), K3PO4-ethylene glycol (K3PO4-EG), was investigated for the separation of spent LiFePO4 (LFP) cathodes. Under the optimal conditions (125 °C, 30 min), K3PO4-EG achieved a stripping efficiency of 99.77%, comparable to K2CO3-EG and substantially higher than K2CO3-Gly and ChCl-EG. X-ray diffraction, ICP-OES, and electron microscopy indicated that treatment with the alkaline DES systems enabled cathode delamination while largely retaining the phase structure and bulk elemental composition of the recovered LFP. FT-IR, Raman, and XPS analyses of treated PVDF were consistent with substantial defluorination and formation of unsaturated carbon species, supporting an alkaline degradation pathway rather than simple binder dissolution. Comparative experiments and density functional theory calculations further suggested that mass transfer may play a dominant role in stripping performance under the optimal conditions. As phosphate is intrinsic to LFP chemistry, the K3PO4-EG system may also offer a component-matched advantage for future LFP-specific recycling routes. These results identify phosphate-based alkaline DESs as promising pretreatment media for LFP cathode delamination.