Changzhou University

The development of co-reactant-free electrochemiluminescence (ECL) is of great significance for simplifying the analysis process, reducing background interference, and enhancing the detection sensitivity in complex biological matrices. In this work, a ternary CuFeV layered double hydroxide (LDH) was synthesized via a facile method and employed as an efficient ECL electrocatalytic material. Without the addition of any co-reactants, CuFeV-LDH could effectively catalyze the in-situ transformation of O₂ and H₂O into reactive oxygen species (ROS), thereby triggering the generation of a strong and stable ECL signal in the luminol system. Experimental characterization combined with density functional theory (DFT) calculations confirms that the introduction of Vanadium optimizes the spin-orbital distribution of the active Cu and Fe centers. This modulation significantly facilitates the charge transfer of oxygen species at the catalyst interface, inducing the generation of abundant ROS to drive ECL. Based on the effective scavenging effect of glutathione (GSH) on ROS, a sensitive ECL sensing platform for GSH detection was further constructed. The sensor exhibited a good linear relationship in the concentration range from 1 × 10^-9 to 1 × 10^-5 M, with a low detection limit of 0.3 nM. In addition, the proposed sensor demonstrated excellent selectivity, long-term stability, and practical applicability in real sample analysis, providing a new strategy for the development of novel co-reactant-free ECL biosensing platforms.

Efficient interfacial water activation and favorable hydrogen spillover (HSo) are two indispensable prerequisites for high-performance alkaline seawater hydrogen evolution reaction (HER), as both jointly govern the sluggish reaction kinetics that severely restrict seawater electrolysis toward green hydrogen production. Developing robust HER electrocatalysts capable of simultaneously optimizing these two processes therefore stands as a core demand for viable alkaline seawater hydrogen generation. In this work, we construct PtRu bimetal-decorated CoP nanorods with a hierarchical high-curvature structure that generates distinctive localized tip electric fields for enhanced alkaline seawater HER. Mechanistic investigations reveal that the tip-induced local electric field activates interfacial water and lowers the water dissociation energy barrier, while the interfacial electron density gradient drives efficient HSo. The synergy of these two effects simultaneously upgrades the HER performance in pure alkaline electrolyte and alkaline seawater. Electrochemical tests demonstrate that the catalyst requires only an overpotential of 25 mV to reach a current density of 10 mA·cm^-2 in 1 M KOH, with a Tafel slope of 52.8 mV·dec^-1, and can operate stably for 135 h. In the 1 M KOH + 0.5 M NaCl simulated seawater system, the performance is comparable to that in the pure alkaline electrolyte, while in the natural seawater alkaline electrolyte, it still delivers a HER activity of 68 mV@10 mA·cm^-2 and operational stability over 100 h. This work elucidates the multilevel synergistic mechanism among the localized electric field, interfacial water activation and HSo, providing new insights and an experimental basis for the rational design of high-performance alkaline seawater HER catalysts.

Constructing polyion complex (PIC) networks with dense electrostatic interactions is a well-established strategy to enhance the strength and toughness of hydrogels. However, for polyion combinations with weak association energy, the construction of robust hydrogel networks is typically challenging. In this work, a PIC hydrogel integrating electrostatic and hydrogen bonding interactions was fabricated by polymerizing acrylic acid (AA) and acrylamide (AM) in a partially deprotonated polyallylamine hydrochloride (DPAH) solution. Subsequent dehydration-rehydration treatment enabled densification of the network structure. It is revealed that the dehydration-rehydration process not only reinforces the ionic cross-linked network and significantly elevates the network's flow activation energy but also enhances the hydrogel's hydrophobicity via enhanced ion-pairing interactions. Conversely, hydrogen bonding interactions from the introduced amide groups disrupt the originally dense intermolecular electrostatic interactions and accelerate the relaxation kinetics of the polymeric network. After dehydration-rehydration treatment, the tensile strength of the hydrogel was enhanced by approximately 32-fold, reaching ∼10 MPa, and the fracture toughness was elevated from about 0.05 to ∼11.61 MJ m^-3, demonstrating ideal toughening and strengthening effects. Owing to its superior anti-swelling property derived from the enhanced hydrophobicity, the hydrogel can be well applied as flexible sensors for real-time monitoring of underwater motion, exhibiting robust signal transmission stability. This work presents a facile and novel strategy to diversify high-performance PIC hydrogel systems, especially those with inherently weak association energy, thus providing a new perspective for the design of hydrogel platforms for underwater applications.