This study reports a frost-resilient nanocomposite hydrogel engineered for flexible electronics operating under cryogenic conditions. The hydrogel integrates a polyvinyl alcohol-guar gum (PVA-GG) dual-network matrix with cellulose nanocrystals (CNCs) grafted with glycosylated borate ammonium phytate (GBAP) and L-proline (L-Pro), forming hierarchical hybrid reinforcements through molecular interface engineering. Phytic acid (PA) enables multivalent coordination crosslinking, while L-Pro provides cryoprotection and maintains ductility at low temperatures. The resulting hydrogel exhibits excellent stability at -20 degrees C, including a tensile modulus of 2.11 MPa and 92.94 % self-healing efficiency. As a flexible sensor, it delivers a gauge factor of 2.72 and a rapid response time of 270 ms at -20 degrees C, enabling reliable monitoring of human motion. This work presents a scalable strategy for designing hydrogels with synergistic mechanical, self-healing, and anti-freezing capabilities, advancing flexible electronics for extreme-environment, wearable, and biomedical applications.

Elucidating the structure–activity relationship between the electronic structure of catalytic active sites and oxygen evolution reaction (OER) activity at the orbital level is critical yet challenging in lithium–oxygen (Li–O2) batteries. Herein, employing frontier molecular orbital theory, we designed a Pt-based catalyst as a model cathode to investigate the influence of frontier orbital interactions between the Pt dz2 orbital and the 5σ orbital of LiO2 on the OER activity. Specifically, compared to the pure Pt catalyst, the dz2–dz2 orbital coupling between low-electronegativity Fe and Pt in PtFe catalyst induces predominant electron transfer from Fe to the dz2 frontier orbital of Pt. As the Pt content in PtFe alloys increases progressively (from Pt58Fe42, Pt67Fe33 to Pt76Fe24), the electron population of the Pt 5dz2 orbital gradually decreases (1.92 for Pt58Fe42, 1.85 for Pt67Fe33, and 1.80 for Pt76Fe24). This leads to a gradual enhancement in the strength of interactions between the Pt dz2 orbital and the frontier orbitals of LiO2, consequently resulting in a progressive decline in the OER catalytic activity. Establishing the correlating between the electron population in the dz2 frontier orbital and OER activity provides a descriptor for designing efficient electrocatalysts in Li–O2 batteries.

Current wearable flexible sensors demonstrate capability for analyzing sweat composition. However, the monitoring of human motion and sweat glucose levels remains a formidable challenge. Herein, we developed a flexible sensor based on a reduced graphene oxide-3-Aminophenylboronic acid (rGO-APBA) functionalized electrode integrated with a cellulose nanocrystals (CNCs) hydrogel. The introduction of APBA enhanced the electrochemical performance of the sensor. This sensor enabled synchronous monitoring of mechanical motion and sweat biomarkers. And it had excellent mechanical properties, adhesion, and self-healing capability (>89 %). Meanwhile, this sensor also wide sensing detection range (0-550 %) a linear detection range of 3-250.0 mu M, a low detection limit (0.96 mu M). Notably, a dual-function sensor capable of detecting both human motion and sweat detection has been developed which provided a non-enzymatic alternative solution for advanced wearable sweat sensors.

This study develops a low-cost, paper-based natural air diffusion electrode (PNADE) for electrochemical H2O2 production as a green alternative to the energy-intensive anthraquinone process. By utilizing cellulose paper fibers as the substrate and carbon black (CB) as the catalyst, the PNADE eliminates the need for pressurized oxygen supply systems through efficient oxygen self-diffusion. Systematic optimisation reveals that a 5% PVDF binder ratio maximises catalytic activity (81.8% H2O2 selectivity, 2.36 electron transfer number). Concurrently, a 6: 4 mass ratio of mercerised pulp to fibrillated pulp (MP: PRT) balances electrode integrity and gas permeability. Under ambient air at 60 mA cm(-2), the electrode delivered a H2O2 production rate of 572.82 mg L-1 h(-1) with a current efficiency above 75% over 3 h. Stable operation was further demonstrated in a 24 h continuous-flow reactor (1 mL min(-1)), producing 1540 mL of H2O2 solution at 435.96 mg L-1 with a current efficiency of similar to 73%. Throughout the electrode fabrication process, conventional papermaking techniques were employed, highlighting the strong potential for batch production and large-scale manufacturing. This scalable and environmentally friendly design provides a promising strategy for the application of paper-based electrodes in hydrogen peroxide synthesis.

Constructed 2D/2D ultrathin g-C 3 N 4 /BiOI heterojunction and its derived PSF system promoted Fe cycling and charge separation, enabling deep pollutant mineralization.

The development of efficient photocatalytic self-Fenton (PSF) systems capable of in situ H2O2 generation is crucial for sustainable water remediation. Herein, a 0D/1D heterojunction photocatalyst composed of WO3 quantum dots (QDs) anchored on CdS nanowires is constructed to achieve high-performance PSF degradation of 2,4-dichlorophenol (2,4-DCP). The optimized photocatalyst exhibits exceptional visible-light activity, degrading 98.0% of 2,4-DCP within 3 h, with a rate constant 48.0% higher than pristine CdS. Mechanistic studies and density functional theory (DFT) calculations reveal that the heterojunction narrows the bandgap and enhances charge separation. Holes (h+) oxidation dominates the degradation process, with hydroxyl radicals (& sdot;OH) identified as primary reaction species, evidenced by electron spin resonance (ESR) spectroscopy and radical scavenger experiments. The in situ generated H2O2 is efficiently consumed via Fe3+/Fe2+ cycling to sustain & sdot;OH production, enabling a stable PSF cycle. In addition, the degradation process of 2,4-DCP under visible light irradiation was revealed using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). This work provides a viable design strategy for multifunctional heterojunctions in advanced oxidation processes.

Solar-driven hydrogen peroxide (H2O2) synthesis from water and oxygen stands as a sustainable and viable strategy, yet its progress remains constrained by the lack of high-performance photocatalysts. Here we report a Pd atomic site on tetrakis (4-carboxyphenyl) porphyrin supramolecular nanosheet catalyst for photocatalytic H2O2 production. The optimized catalyst achieves an exceptional H2O2 yield rate of 608 mu mol g- 1 h- 1 under visible light. A combination of experimental investigations and theoretical simulations verifies that the H2O2 generation proceeds via a dual-pathway mechanism, encompassing both the oxygen reduction reaction (ORR) and the water oxidation reaction (WOR). The Pd atomic sites not only enhance visible-light absorption and facilitate charge transport, but also serve as efficient electron traps that significantly lower the energy barriers for the formation of key intermediates (*OOH for the ORR pathway and *OH for the WOR pathway). This work presents a high-performance photocatalytic system and delivers atomic-scale insights into the sustainable solardriven H2O2 synthesis process.

Hydrogel-based flexible sensors have attracted significant attention due to their excellent deformability and ionic conductivity. However, their practical application in cold environments is severely limited by water freezing, which leads to mechanical failure and loss of functionality. To address this issue, this study proposes a seawaterenabled strategy to construct an anti-freezing hydrogel (named S-PHC) via a facile one-pot method. Seawater (SW), serving as a natural electrolyte, contains abundant free metal ions that disrupt the hydrogen-bonding network of water through ion-dipole interactions, effectively suppressing ice crystallization and lowering the freezing point. Meanwhile, multivalent ions (e.g., Ca2+, Mg2+) establish electrostatic crosslinking with humic acid (HA) and interact with hydroxyl groups in phytic acid-functionalized cellulose nanocrystals (CNCs@PA) and free water molecules, further enhancing network stability and reducing the freezing point to 30.1 degrees C. In addition, the incorporation of CNCs@PA significantly improves the mechanical performance, achieving a tensile strength of 2.1 MPa and a self-healing efficiency of 86%. The resulting S-PHC-based flexible sensor exhibits high sensitivity (gauge factor, GF = 3.22) and stable conductivity (1.64 S center dot m(-1)) even at -20 degrees C, enabling accurate detection of human motion. This work provides a simple and effective strategy for designing anti-freezing hydrogels toward next-generation flexible sensing applications.

Multifunctional flexible sensors with applications in the fields of monitoring human motion and detecting ascorbic acid (AA) in sweat have received more and more attention. Carbon material-based hydrogels show great potential to construct multifunctional flexible sensors, while sensitive and selective detection of AA is still challenging. Herein, the tetraphenyl porphyrin@carbon fiber (TPP@CF) hydrogels were designed for enhancing identification of AA in sweat by an electrostatic interaction strategy. TPP is incorporated in CF to ensure the sensitivity of detecting AA. Hexadecyl trimethyl ammonium bromide (CTAB) with positive charge is adding for not only enabling selective detection of negatively charged AA, but also enhancing dispersion of TPP@CF, and concurrently improving the mechanical properties and electrical conductivity of hydrogels. The fabricated multifunctional hydrogel sensors exhibit preferable mechanical strength (1.41 MPa) and high conductivity (0.17 S/m), enabling accurate detection of AA with a low detection limit of 1.31 μM. Notably, it enables non-invasive, real-time acquisition of health-relevant biomarkers from human sweat, thereby opening an avenue for personalized health management.

Wearable flexible sweat sensors offer a powerful platform for noninvasive health monitoring, yet their stable operation at low temperatures remains a critical challenge. Herein, we design an antifreezing, self-healing bilayer Janus hydrogel comprising a NiTPP/BSA/CFs/PA-PVA sensing layer and a Collagen-PVA self-healing layer. In the sensing layer, phytic acid (PA) converts free water into bound water via hydrogen bonding, lowering the freezing point to -21.4 °C. This enables the hydrogel to maintain high stretchability (623.4%) and strain sensitivity (GF = 1.11) even at -20 °C. Furthermore, bovine serum albumin (BSA)-modified carbon fibers loaded with nickel(II) tetraphenylporphyrin (NiTPP) provide robust electrocatalytic selectivity, achieving a low detection limit of 0.68 μM for sweat glucose. The adjacent Collagen-PVA layer exploits dynamic hydrogen bonds and physical entanglements to endow the hydrogel with an 87.5% self-healing efficiency and excellent skin affinity. United by stable physical cross-linking at the interface, this Janus architecture integrates antifreezing, self-healing, and multimodal sensing capabilities, offering a promising strategy for robust wearable biosensing in extremely cold environments.

Wearable electrochemical sensors have gained increasing attention for non-invasive, real-time monitoring of sweat biomarkers, particularly for applications such as diabetes management. However, the integration of high sensitivity, strong adhesion, and anti-freezing capabilities into a single flexible sensing platform remains a significant challenge. To address this, we present a Janus hydrogel-based wearable glucose sensor that integrates asymmetric material design for multifunctional performance. The hydrogel patch consists of a carboxymethyl cellulose/polyvinyl alcohol (CMC/PVA) matrix with two functionally distinct layers formed by the addition of different substances. The outer layer is modified with glycerol (GLY), which imparts excellent anti-freezing properties, maintaining flexibility under low-temperature conditions. Polydopamine (PDA) was added to the inner hydrogel to enhance adhesion, and glucose oxidase-modified polyethyleneimine-coated gold nanorods (GOD@PEI@AuNRs) were added to improve the detection ability of the glucose sensor. This Janus hydrogel has an antifreeze temperature of -38 °C and a wide detection range (10-350 μM) with a detection limit as low as 0.21 μM.

Soilless cultivation relies on hydrogel matrices for water and nutrient management, but conventional hydrogels lose performance at low temperature and show unstable sustained release. Here this study develops an antifreeze sustained-release hydrogel (P-GTCH) that integrates l-proline (L-P) with a humic-acid-modified cellulose nanocrystal nanocomposite (CNCs-HA) for nanoenabled controlled release. L-P suppresses ice nucleation via hydrogen bonding, while CNCs-HA boosts HA loading and enables controlled transport within the cross-linked network. HA shows slow, continuous release governed by Fickian diffusion, achieving 96.7% cumulative release over 12 days at 0 °C and mitigating poor fertilizer release in cold environments. P-GTCH provides mechanical support for plant roots, and the synergistic effects of L-P and HA maintain lettuce germination above 86% at 0 °C while promoting root growth. This biobased, biodegradable platform is scalable for low-temperature soilless cultivation.

Aiming at the insufficient removal of volatile organic compounds (VOCs) and pollutant enrichment in solar-driven evaporation technology, a Janus all-starch NS/B-CQD aerogel (NBCJ) with synergistic photothermalphotocatalytic function was designed. The evaporator was designed using corn starch (CS) as both threedimensional aerogel skeleton with asymmetric wettability and precursor of NS/B-doped CQD (NB) homojunction with photothermal-catalytic conversion. The water remarkable evaporation rates achieved 1.83 kg m-2 h-1 with 90.3% of photothermal conversion efficiency under 1 kW m-2 irradiation. Simultaneously, it generates reactive oxygen species (& sdot;OH/1O2), degrading 92.5% of phenol with 83.6% of mineralization rate within 180 min. The unique upper hydrophilic and lower hydrophobic Janus porous structure endowed NBCJ with good thermal management and buoyancy upon water surface, which can minimize heat conduction to the bulk water. The electronic-structure engineering adopted for NB homojunction provide optimized energy band for broadspectrum absorption and carriers' migration, thus facilitate the high-efficiency redox reaction at higher potentials. The long-term stability test showed that NBCJ maintained a photothermal conversion efficiency of 89.1% and phenol degradation efficiency of 80.8%. This system simultaneously addresses water pollution accumulation during evaporation and condensate purification commanded by intrinsic material-level synergy and establishes a novel approach for wastewater purification.

In heterogeneous electro-Fenton (EF) systems, the limited generation of reactive oxygen species (ROS), insufficient exposure of active sites, and sluggish electron transport collectively impede the degradation of perfluorooctanoic acid (PFOA). Herein, a one-dimensional (1D) Cu-MOF-derived carbon aerogel featuring hierarchical fluorophilic channels is rationally engineered to realize directionally confined catalysis of PFOA. The multiscale pore architecture and fluorine-affinitive interfaces promoted the efficient enrichment and guided transport of PFOA molecules, thereby minimizing diffusion resistance toward catalytically active sites. The confined microenvironment accelerates interfacial electron transfer and shortens the mass-transfer distance between ROS and pollutants, facilitating C-F bond cleavage and markedly enhancing PFOA mineralization. Meanwhile, the one-dimensional conductive framework facilitates electron transport and contributes to the structural stability of the catalyst during the catalytic process. High-temperature calcination enables precise control of the Cu+/Cu2+ ratio, thereby favoring the in situ generation of center dot OH and center dot O2- radicals. Significantly, the center dot O2- generated in situ at the cathode can initiate PFOA decarboxylation, enabling an efficient single-cathode degradation process that does not rely on the anode. The catalyst exhibits outstanding performance even in complex water matrices. This study provides a compelling strategy for designing efficient and durable catalysts for the remediation of perfluorinated contaminants.

Water pollution caused by Pb(II) is a significant environmental problem that has hazardous effects on ecological safety and human health. Adsorption is an attractive method for the remediation of Pb(II) pollution. The synthesis of an efficient adsorbent to achieve selective adsorption of Pb(II) is the focus of extensive research. Herein, functionalized magnetic Fe3O4 composites were constructed for the selective adsorption of Pb(II) by employing diethylenetriamine (DETA), aminomethylpyridine (AMP), arginine (ARG), and thiosemicarbazide (TSC) as functional groups. The adsorption performance and mechanism of the composites for Pb(II) were systematically investigated. The composites display a satisfactory adsorption capacity for Pb(II). The normalized adsorption capacity of DETA-functionalized composites for Pb(II) is 1.33 mmolmmol-1, which is 2.11, 2.13, and 1.52 times that of AMP-, ARG-, and TSC-functionalized composites. The optimal adsorption pH for Pb(II) is 6. The adsorption can be promoted by raising the Pb(II) concentration and temperature. Adsorption kinetics indicates film diffusion is the rate-controlling step and the adsorption follows a pseudo-second-order model. The composites exhibit a marked adsorption selectivity for Pb(II). The increase of concentration, column bed height, and reduced flow rate of solution can promote the dynamic adsorption for Pb(II). The composites also display good adsorption performance and reusability in simulated industrial wastewater. The adsorption capacity of DETA-functionalized composites can retain 97.00% after 3 cycles of regeneration. The adsorption mechanism demonstrates the capture of Pb(II) is mainly dependent on amino, oxygen, and sulfur groups. The work not only provides a feasible method to quantitatively evaluate the adsorption ability of different functional groups but also paves a new way for the preparation of efficient adsorbents to realize the efficient adsorption of Pb(II) from aqueous solutions.

Electroreduction of lignin into value-added chemicals offers an effective route for its high-value utilization. However, how the electronic states of catalytic sites govern lignin conversion efficiency and product yield remains poorly understood. Here, we use Pt and a Pd@Pt heterostructure as model catalysts to systematically investigate catalyst-intermediate interactions and their influence on lignin electroreduction. In the Pd@Pt heterostructure, electron transfer from Pd to Pt reconstructs the Pt 5d states and shifts the catalyst-intermediate interaction from a strong Pt 5dxz-O 2py interaction on pure Pt with C6H5OH/C6H5COCH3 to a weaker Pt 5dxy/yz-O 2px interaction on Pd@Pt. This reduced orbital overlap significantly lowers the activation barrier of the rate-determining step, thereby enhancing lignin reduction activity. These findings highlight the critical role of orbital interaction modes in regulating catalyst activity and provide mechanistic insight for the rational design of advanced electrocatalysts for lignin reduction.

In recent years, hydrogels have emerged as viable candidates for soft conductors in wearable flexible electronics, due to their distinctive properties including high water content, excellent biocompatibility, and adjustable mechanical properties. However, the crystallization of H2O molecules within hydrogels at low temperatures leads to significant deterioration in their toughness and mechanical strength, severely restricting their practical applications in cold environments. Cellulose nanocrystals (CNCs), rod-like nanomaterials with high crystallinity extracted from natural cellulose, have attracted increasing attention due to their outstanding mechanical properties, biocompatibility, and environmental friendliness. In this study, hyaluronic acid (HA) was adsorbed onto the surface of CNCs via hydrogen bonding, forming CNCs@HA nanomaterials. And then zwitterion proline (ZP) and CNCs@HA were incorporated into an acrylic acid-based hydrogel system, resulting in the formation of a novel freeze-resistant and self-healing nanocomposite hydrogel PAA-CNCs@HA-ZP-Fe3+ (PCHZF). The excellent properties of PCHZF can be attributed to the strong hydrogen bonding network formed among water molecules, CNCs@HA, and ZP molecules. These intermolecular interactions effectively inhibit the crystallization of water and maintain the integrity of the hydrogel matrix at low temperatures. Its compressive strength reaches 2.2 MPa, with a remarkable self-healing efficiency of 88.2%, and it can even achieve reliable sensing performance at extremely low temperatures.

The development of hydrogels that integrate antifreeze, self-healing, and conductive properties is crucial for advancing flexible sensors capable of operating in extreme environments. In this study, we fabricated a multifunctional nanocomposite hydrogel (MPC-P) characterized by antifreeze performance and self-healing capabilities. By utilizing phytic acid (PA) as a key cryoprotectant, the hydrogel's operational temperature range was successfully extended to -20 degrees C. To synergistically enhance this antifreeze framework, MXene@PDA/CNC nanocomposites (MPCs) were incorporated, endowing the MPC-P with superior mechanical strength (maximum stress: 2.33 MPa) and high flexibility (elongation at break: 508.6%). Notably, the MPC-P hydrogel retains exceptional performance even at subzero temperatures, exhibiting high self-healing efficiency (90.1% at 25 degrees C and 84.8% at -20 degrees C) and rapid response/recovery times (340.0 ms/280.0 ms). These features ensure reliable signal detection under repeated deformation in extreme cold, positioning MPC-P as a promising candidate for next-generation low-temperature wearable electronics.

Photocatalysis self-Fenton (PSF) represents a promising approach for organic pollutant treatment, yet existing photocatalysts suffer from insufficient degradation efficiency and mineralization. Here, we construct a 2D/2D interfacial heterojunction system through the integration of g-C3N4 and BiOI nanosheets, targeting efficient decomposition and thorough mineralization of persistent organic pollutants. Under visible-light irradiation, this system efficiently generates H2O2via an oxygen reduction pathway, and subsequently activates a Fenton reaction, producing highly reactive OH radicals. Complete degradation of bisphenol A was achieved within 60 min, accompanied by a mineralization rate of 64.4%. The system also demonstrates superior performance across various pollutants, exhibiting excellent versatility. Experimental characterization and theoretical calculation reveal that the type-I band alignment at the heterointerface drives photogenerated carrier separation through a built-in electric field, while the 2D architecture enhances charge transfer efficiency. This study provides both theoretical and technical insights into the design and application of PSF systems in environmental remediation.