Generally, it is essential to externally introduce redox probes for cortisol detection through molecularly imprinted electrochemical sensor. However, this approach complicates the detection process, hinders real-time monitoring and may cause significant interference during body fluid analysis. To address the issue, we innovatively proposed a self-signal sensor based on humic acid (HA)-mediated conductive redox nanoprobe. Amphiphilic HA can effectively coat multi-walled carbon nanotubes (MWCNT) through it-it interactions, providing exceptional dispersibility while retained conductivity. Additionally, due to its colloidal characteristics, the HA coated MWCNT exhibited remarkable adsorption capacity towards various types of redox molecules, particularly cationic redox species, thus acquiring a kind of conductive redox nanoprobe in a facile way. The nanoprobe could serve as a bottom layer to prepare an electrochemical sensor in combination with cortisolimprinted polydopamine as the upper layer. Finally, a self-signal electrochemical sensor for cortisol was successfully fabricated, achieving a detection limit of 0.72 x 10-9 M, a wide detection range from 1 nM to 1 mM and good recovery. Overall, we believe the HA-mediated strategy proposed in this study could inspire more innovation in the field of self-signal sensing.

The oxygen evolution reaction (OER) suffers from sluggish kinetics, necessitating efficient electrocatalysts to reduce overpotentials in water splitting. Currently recognized OER mechanisms primarily include the adsorbate evolution mechanism (AEM), lattice oxygen mechanism (LOM), and oxide path mechanism (OPM). Compared to AEM, limited by scaling relationships, and LOM, constrained by stability issues, the OPM offers a promising alternative by enabling direct O–O bond formation via dual active sites, thus bypassing *OOH intermediates and lattice O involvement and achieving a balance between activity and durability. However, activating the OPM process requires precise control over the spatial and electronic structure of active sites, making the design of OPM-based catalysts challenging. While previous reviews have focused on homo/heteronuclear diatomic perspectives of OPM-based catalysts, it is urgent to systematically summarize design strategies to provide a rational reference for their development. Herein, a review of design strategies for OPM-based OER catalysts across three scales is comprehensively presented, including in-situ engineering, doping-enabled sites reconstruction, and introducing new sites for nanoparticles, direct synthesis or post-treatments for molecular catalysts, and doping or template strategies for atom pairs or arrays. The unique advantage of atom arrays is also highlighted, and their future research directions and possible strategies are discussed. This review provides a systematic summary and forward-looking perspectives for rationally designing high-performance OPM-based OER catalysts.

Interfacial water structure critically influences CO2 electroreduction pathway and product selectivity, yet molecular-level strategies to precisely regulate interfacial solvation and quantitatively correlate it with C-C coupling remain limited. Here, we report a hydrogel-mediated, customizable interfacial solvation strategy by integrating an ultrathin, ion-cross-linked, water-retentive hydrogel layer on Cu (Cu-IWH), formed via coordination between chitosan and divalent metal cations. The resulting charged and hydrated interface enables controlled modulation of the interfacial electrostatics, ion hydration, and local chemical environment, thereby steering CO2 electroreduction toward C2+ products. In situ Raman spectroscopy reveals that solvated K+(H2O)n species interact with adsorbed hydroxyl groups (OHad), leading to a reorganization of the interfacial hydration structure and the formation of Cu·OHad·K+(H2O)n* interfacial complexes. By tuning the hydrogel cross-linking density, an optimal balance between OHad coverage and cation accessibility is achieved, maximizing the population of these complexes, which shows a quantitative correlation with enhanced C2+ selectivity. Density functional theory calculations further show that these complexes induce interfacial charge redistribution, stabilize *CO adsorption in configurations favorable for C-C coupling, and lower the kinetic barrier for *CO-*CO dimerization. Meanwhile, the hydrogel matrix enriches interfacial OH-, creating a locally alkaline microenvironment that promotes *COL/*COB coadsorption and facilitates C-C coupling. As a result, the optimized Cu-IWHM catalyst delivers a C2+ Faradaic efficiency of 87.5% at -1.2 A cm-2 and a single-pass carbon efficiency of 94.3% at -1.0 A cm-2, while sustaining stable operation for over 800 h at 800 mA in a 4 cm2 MEA electrolyzer. When scaling to a 100 cm2 MEA, the system achieves 81.5% C2+ selectivity with a C2+ energy efficiency of 34.0% at 40 A and operates stably for 82 h at 20 A. This work establishes hydrogel-mediated interfacial solvation engineering as a tunable approach for regulating interfacial environments and promoting C-C coupling in CO2 electrocatalysis.

The rapid development of electric vehicle batteries and large-scale grid energy storage systems has led to a substantial surge in global lithium (Li) demand. While abundant in brine and seawater, its extraction requires efficient and low-energy methods. Unlike established physicochemical or electrically-driven Li extraction processes, the emerging photothermal technology offers a cleaner and lower-cost alternative. This promising approach leverages abundant solar energy via photothermal materials to drive brine/seawater evaporation and concentrate Li+ for capture. Its core relies on synergistic coupling between photothermal units and Li extraction units. Crucially, systems design for photothermal Li extraction is of utmost importance for achieving high efficiency, selectivity, and stability. Unlike previous reviews focusing on extraction methods, this review reveals the impact of coupling interactions between photothermal units and Li extraction units on photothermal Li extraction performance. Based on the coupling interactions between the two functional units, this study defines integrated systems (where units are assembled within a single matrix) and non-integrated systems (where units exist in separate matrices). We further systematically summarize the synergistic enhancement effects of photothermal materials and Li extraction materials on Li extraction in each system. Finally, we present outlooks for the photothermal Li extraction system from four perspectives.

A graphene-based material for the selective adsorption of gallium ions has been prepared by combining ion-imprinting technology with adsorption. This material is capable of separating and extracting gallium ions from the acid leachate of fly ash. Morphological and structural characterization of the material was performed using scanning electron microscopy and Fourier-transform infrared spectroscopy, which confirmed that the material possesses a three-dimensional structure and that functional monomers have successfully complexed with graphene oxide substrates. The maximum adsorption capacity of the material reaches 86.29 mg/g at a solution pH of 3. In the selective adsorption tests, the selective separation factors of gallium ions relative to aluminum, magnesium, iron, and calcium ions were 16.50, 49.50, 9.90, and 99.00, respectively. Meanwhile, the material maintained excellent adsorption capacity and structural stability in cyclic regeneration experiments, with no obvious dissolution loss observed. The adsorption mechanism of the material was analyzed via X-ray photoelectron spectroscopy, and the results indicated that it primarily involves cation exchange between carboxyl groups and gallium ions. This work demonstrates that the three-dimensional ion-imprinted hydrogel adsorbent plays a significant role in the selective adsorption of gallium ions and the subsequent solid-liquid separation.

ABSTRACT Heterostructures can accelerate the alkaline hydrogen evolution reaction (HER) through the typical “dual‐site” mechanism, where one site is responsible for water cleavage while the other facilitates hydrogen generation. However, this dual‐site mechanism never fully exploits the interface functions due to interfacial disorder in conventional heterostructures, thereby hindering the full activation of the intrinsic catalytic activity. Herein, by constructing an ordered Ru‐W 2 C Janus Schottky junction, we overcome the constraint of the typical dual‐site mechanism and facilitate the full activation of the Schottky junction. Experiments and calculations reveal a distinct reaction pathway in which both sides of the Janus Ru‐W 2 C Schottky junction simultaneously dissociate water, serving as “dual channels” to supply H* to the interfacial active sites. Enabled by the “dual‐channel H supply” mechanism, the HER proceeds with a low energy barrier and a short reaction pathway, allowing the corresponding alkaline anion‐exchange membrane water electrolyzer to operate stably at 1.79 V and 1.0 A cm −2 for over 400 h. This work demonstrates that the precise Janus design serves as an effective strategy to achieve the “dual‐channel H* supply” in alkaline HER, thereby providing novel perspectives for the design of catalysts in hydrogen‐related reactions.

Supported alloys can lower alkaline water dissociation barrier via dual-metal synergy. However, weak support-alloy interactions usually bottleneck interfacial charge transfer and thus impede water dissociation. Herein, metal-support interfacial engineering is exploited to construct a microporous carbon nanomesh (MCN) that tightly bridges Pt3Co nanoparticles to carbon nanotubes (CNT@Pt3Co-MCN) by confinement. Computation indicates that this confinement effect of MCN endows Pt with additional electrons, thereby enhancing its electrostatic attraction toward the hydrogen atoms of water molecules. This significantly promotes water activation by facilitating hydrogen abstraction, accelerating the cleavage of the H-OH bond. Thus, the CNT@Pt3Co-MCN achieves a low voltage (1.939 V) and excellent stability in alkaline membrane electrode assemblies. This work offers a general interfacial-engineering paradigm to tailor support-metal interaction for efficient water dissociation over alloy catalysts in alkaline.

Heavy metal contamination-induced water scarcity poses a severe threat to human health, driving the need for advanced adsorbents. Hydrogels offer promise for heavy metal removal due to their abundant adsorption sites. Recently, coupling photothermal materials (e.g., carbon materials, polymers) with hydrogels has been applied to enhance adsorption efficiency and kinetics via synergistic effects. However, despite these significant advancements, there is a notable lack of comprehensive reviews in this area. To address this gap, this review systematically summarizes the photothermal hybrid hydrogels used for heavy metal removal. From the perspective of photothermal material-hydrogel interface structure regulation, this review focuses on investigating the structural design strategies of photothermal hybrid hydrogels (carbon-based, polymer-based, metal compound-based, and composite-based hydrogels) and the structure-performance relationships of various hydrogels in heavy metal removal. Furthermore, this review presents perspectives on challenges including agglomeration of photothermal materials, diurnal intermittency and environmental sustainability of photothermal hydrogels. This review provides insights essential for advancing the application of photothermal hybrid hydrogels in complex wastewater treatment.

Lithium-ion sieve (LIS) hydrogels offer a solution to powder loss and poor site accessibility of LIS in lithium extraction through swelling. However, their adsorption efficiency is constrained by the inherently slow diffusion of lithium ions (Li+) through tortuous pathways within the hydrogel matrix. Herein, we regulate Li+ transport channels in LIS hydrogels by engineering dynamic adsorption networks through swelling enhancement with anionic surfactants. By integrating pulsed-field gradient nuclear magnetic resonance (PFG-NMR) diffusion experiments with molecular dynamics simulations, we demonstrate that rapid swelling creates low-tortuosity percolation channels, which significantly accelerate Li+ diffusion and enhance active-site accessibility during adsorption. So, the LIS hydrogel achieves a Li+ adsorption capacity of 52.79 mg g-1 HMO, approaching the theoretical capacity, with a high adsorption rate constant of 5.85 mg mg-1 h-1. The LIS hydrogel retains over 80% of its capacity after 20 cycles while reducing Mn2+ dissolution loss. In natural Bohai seawater, it shows high Li+ selectivity and delivers a Li+ adsorption capacity of 12.45 mg g-1 HMO in a 15-day scaled-up extraction test. The accelerated swelling by anionic surfactant micelles also enhances photothermal lithium extraction efficiency by modulating water states. This work provides a general and robust strategy for designing high-efficiency adsorbents for the reversible extraction of strategic metals from natural seawater.

Efficient and durable electrochemical conversion of CO2 to formate at industrially relevant current densities remains challenging, as Sn-based catalysts often suffer from poor conductivity, structural degradation, and overly strong binding to key reaction intermediates. Here, we introduce a nanogrid-directed interfacial electric field engineering strategy that addresses these limitations by spatially confining Sn nanoparticles within a conductive carbon nanotube nanogrid framework (Sn@CNT). The hierarchical architecture induces intense and well-distributed interfacial electric fields, which accelerate charge transport, optimize the adsorption-desorption kinetics of *HCOOH intermediates, and promote interfacial H2O dissociation while maintaining a favorable local ion environment. As a result, the Sn@CNT catalyst delivers a Faradaic efficiency (FE) of 95.6% for formate at 300 mA cm-2, and maintains over 90% FE for 200 h in a flow cell in alkaline conditions. In the solid-electrolyte cell, the formate combines with protons to yield formic acid, enabling stable production of 1.1 m formic acid at 400 mA for more than 300 h without observable performance decay. Operando spectroscopy and theoretical simulations reveal that the CNT nanogrid establishes a confined interfacial field that redistributes local charges, facilitates H2O activation, and lowers the desorption barrier of *HCOOH intermediates. This cooperative field modulation also establishes a mild microenvironment that enhances CO2 reduction kinetics while suppressing the competing hydrogen evolution reaction. This work demonstrates nanogrid-directed interfacial field engineering as a broadly applicable approach for tailoring electrochemical interfaces, offering design principles for efficient and stable CO2-to-formate electrosynthesis.

Heterostructures can accelerate the alkaline hydrogen evolution reaction (HER) through the typical "dual-site" mechanism, where one site is responsible for water cleavage while the other facilitates hydrogen generation. However, this dual-site mechanism never fully exploits the interface functions due to interfacial disorder in conventional heterostructures, thereby hindering the full activation of the intrinsic catalytic activity. Herein, by constructing an ordered Ru-W2C Janus Schottky junction, we overcome the constraint of the typical dual-site mechanism and facilitate the full activation of the Schottky junction. Experiments and calculations reveal a distinct reaction pathway in which both sides of the Janus Ru-W2C Schottky junction simultaneously dissociate water, serving as "dual channels" to supply H* to the interfacial active sites. Enabled by the "dual-channel H supply" mechanism, the HER proceeds with a low energy barrier and a short reaction pathway, allowing the corresponding alkaline anion-exchange membrane water electrolyzer to operate stably at 1.79 V and 1.0 A cm-2 for over 400 h. This work demonstrates that the precise Janus design serves as an effective strategy to achieve the "dual-channel H* supply" in alkaline HER, thereby providing novel perspectives for the design of catalysts in hydrogen-related reactions.

Electrocatalytic hydrogen evolution reaction (HER) faces challenges in alkaline due to competitive adsorption of *OH and *H at the same active site, which hinders H2 generation. Single-atom alloys (SAAs), particularly Ni-based systems like NiPt1 SAAs, show considerable performance through dual-site mechanisms, where Ni adsorbs *OH while Pt facilitates H2 desorption. However, *OH blockage on Ni hinders *OH desorption and triggers slow water dissociation kinetics. Herein, supported NiPt1 alloy nanoclusters embedded with Ni3ZnC0.7 (Ni3ZnC0.7@NiPt1) are synthesized through pyrolysis ofzeolitic imidazolate framework-8 (ZIF-8)@Ni coordination compound (ZIF-8@NCC) coupled with Pt galvanic replacement reactions. Experiments and calculations reveal that the embedded Ni3ZnC0.7 modulates electronic structure of Ni, promoting *OH desorption and enhancing water dissociation. Thus, supported Ni3ZnC0.7@NiPt1 achieves exceptional low overpotential (eta 10 = 23 mV) and high mass activity (MA50 = 1.67 mAmu gPt-1) in alkaline, which remarkably surpass Ni@NiPt1 (eta 10 = 127 mV and MA50 = 0.101 mAmu gPt-1). The corresponding alkaline anion-exchange membrane water electrolyzer (AEMWE) requires only 1.91 Vat 1 Acm-2, demonstrating industrial viability. This work provides new insights into addressing *OH blockage on SAAs catalysts in alkaline HER.

Nano‐metal particles integrating with single‐atom catalysts (NMP‐SACs) have been constructed recently for accelerated alkaline hydrogen evolution reaction (HER). However, the design of NMP‐SACs primarily aims at the separate adsorption of *OH and H*, while neglecting the *OH desorption, causing *OH blockage and slow kinetics. To address this, Mo 2 C is introduced to NMP‐SACs (e.g., Pt nanoparticles‐Pt atom, Pt n ‐Pt 1 ) by a “one‐step dual‐confinement pyrolysis” strategy for Pt n ‐Pt 1@Mo2C , where Pt 1 precisely confined by Mo 2 C with Pt n remaining adjacent to Pt 1 @Mo 2 C. Experiments and calculations demonstrate that Mo 2 C acting as an “OH‐baton” helps overcome *OH blockage on Pt 1 , accelerating the separation of H* and *OH and thus promoting spontaneous alkaline water dissociation. Thus, the supported Pt n ‐Pt 1 @Mo 2 C achieves a significantly lower overpotential ( η 10 = 24 mV) and a more than seven times higher mass activity (MA 100 = 4.33 mA µg Pt⁻ 1 ) than Pt n ‐Pt 1 in alkaline. The alkaline anion‐exchange membrane water electrolyzer (AEMWE) delivers a low cell voltage of 1.91 V and durable 120 h of electrolysis at 1.0 A cm −2 . This work proposes a new insight for introducing an “OH‐baton” in a dual‐site catalyst system to achieve spontaneous alkaline water dissociation.

A new method for rapid analysis of ginsenosides in biological samples was established using an embedded dispersive solid-phase microextraction (E-DSPE) technique. Lecithin@silica particles were prepared by embedding SiO2 particles with lecithin (mass ratio 4:7) and used as microextraction materials. The optimum extraction conditions of four ginsenosides from biological samples were as followed, 0.20 g of lecithin@silica particles; 10-minute absorption time; the sample of pH 6.0; and elution solvent methanol. The accuracy and matrix effects (ME %) of the method were studied by adding the four ginsenoside standards to enzymatic solutions, decoction and urine samples for assessment. Recovery rate (REC %) of the four ginsenosides at three concentrations of the lowest (Cl), middle (Cm), and highest (Ch) level within the calibration curves were in the range of 82.36∼114.71 %, 83.15∼116.25 %, 81.94∼115.72 %, respectively, and the relative standard deviation (RSD%) values were all <2.91 %. The ME% of the three biological samples were -11.3∼9.08 %, 5.73∼16.71 %, -0.08∼17.62 % and 6.02∼18.21 % for ginsenoside Rg1, Re, Rb1 and Rd respectively. The proposed method was successfully applied to determine ginsenosides in enzymatic solutions, decoction and urine samples with the merits of rapidity, greenness, low cost and high efficiency.

Because of its abundant supply and long-term availability, biomass-based activated carbon is one of the first porous carbon electrode materials recommended for capacitive deionization. This work describes the preparation of biomass distillers' grains-based porous carbon materials with high capacity and quick desalination rates by a sequence of thermal carbonization, chemical activation, and de-ashing from waste distillers' grains of Shanxi Fenjiu Liquor. Compared to other carbon materials, the optimum material had a high salt adsorption capacity of 41.85 mg.g(-1) at 1.2 V with a starting concentration of 500 ppm NaCl. Following acidification during the ash removal process, the material's surface became rich in oxygen-containing functional groups such as carboxyl, as well as a huge number of active sites exposed by the ultra-high specific surface area and profound pore structures. The material had a substantially higher average salt adsorption rate of 17.67 mg.g(-1).min(-1), compared with other carbon materials. After cycles, it maintained 75 % of its maximum capacity in cycle 25. These positive results highlight the potential of biomass distillers' grains-based carbon materials in desalination. This work introduces new ways to treating waste distillers' grains from the Fenjiu liquor production process.

By theoretical modeling and N-species engineering, we develop Co n –Pt 1 @N [5]/[6] C catalysts with optimized N [5] /N [6] coordination. Internal N coordination and external Co coupling enables the achievement of 1.82 V@1 A cm −2 and 400 h stability in AEMWE.

Lithium-ion sieve (LIS)-based adsorption technology offers a promising solution for seawater lithium extraction, as it overcomes the challenge posed by the high Na+/Li+ ratio. However, its broader application is hindered by the performance degradation and dissolution loss of LISs after granulation, as well as the low Li+ concentration in seawater. Herein, we propose an Albizia julibrissin-inspired adsorption-responsive photothermal ion pump (APIP) for enhanced and reversible Li+ extraction from seawater. The APIP integrates an interpenetrating network hydrogel with confined hydrogen manganese oxide (HMO) via an innovative in-situ crosslinking and ion-exchange strategy, ensuring the uniform distribution of HMO. The specific adsorption-responsive swelling behaviour of APIP exposes more adsorption sites, resulting in a high Li+ extraction capacity of 34 mg g-1 HMO, even surpassing HMO powders. Moreover, the low free water characteristics and the selective chelation of the polymer chain on Mn2+ effectively mitigate Mn dissolution. Under solar irradiation, the Li+ extraction kinetics of the APIP increased by a remarkable 2.9-fold owing to the evaporative convection and photothermal effects. Collectively, APIP overcomes the application key limitations of powdered LISs, and opens new avenues for seawater utilization and the advancement of the Sustainable Development Goals.

The serious fouling layer from the nonspecific adsorption in complex media would greatly impair the analytical performance and even lead to the complete failure of the electrochemical sensor. Zwitterionic hydrogel has been demonstrated to possess excellent antifouling capability, while it suffers from a weak interface and spontaneous detachment from the electrode surface due to the double-edged hydrophilicity. Here, we found that the anionic polysaccharide coating on the liquid metal (LM) nanoparticle surface, in combination with the cationic chitosan penetrated in the hydrogel network, could synergistically enhance the interface adhesion while retaining antifouling ability, providing an ingenious solution to this issue. Additionally, only ultrasonic treatment was involved for the preparation of this LM-based zwitterionic hydrogel because ultrasonication could easily induce the formation of LM nanoparticles, the self-assembly of anionic polysaccharide on its surface, and simultaneous free radical polymerization of zwitterionic monomer. Finally, an electrochemical immunosensor was successfully fabricated based on this polysaccharide cross-linked LM-based zwitterionic hydrogel, and an ultralow detection limit of 7.17 pg·mL-1, while a wide linear range from 10 pg·mL-1 to 10 μg·mL-1 was obtained in 100% human serum with negligible difference from that in PBS solution. We believe the polysaccharide-stabilized antifouling hydrogel interface presented in this work could inspire more innovative research for biosensing and bioelectronics in the future.

Herein, we design a high-performance graphene composite aerogel-based particle electrode with superior phenol degradation effect and long-lasting working capability. In situ anchoring c-MOF@NiO heterostructure on c-MOF/ rGA surface was realised with a controlled pyrolysis strategy. The three-dimensional electrocatalytic degradation system composed of c-MOF@NiO/rGA particle electrode achieves 100 % phenol degradation rate in 20 min with a degradation rate constant of 0.1323 min- 1, and maintains a phenol degradation rate of 95.27% after 50 consecutive cycles. Density functional theory calculations show that the c-MOF@NiO heterostructure exhibits the most favorable Delta GOOH*, which effectively promotes the 2e- ORR process and facilitates the generation of H2O2. The defect-induced generation of O2 center dot- and center dot OH together promotes the mineralisation process of phenol. The particle electrode also exhibits good real coking wastewater treatment capability. This work provides a strong motivation for the deep treatment of coking wastewater and the practical process of 3D electrodes.