Hubei University

The sluggish Li + migration kinetics and unstable electrode/electrolyte interface severely hinder the commercial application of high-performance lithium metal batteries (LMBs). Herein, an artificial protective layer is constructed using zwitterionic covalent organic framework (Z-COF) simultaneously containing sulfonate and ethidium groups, aiming to facilitate rapid, uniform Li + transport and stabilize anode interface. The sulfonate groups with high lithiophilicity provide abundant hopping sites for fast Li + diffusion. The ethidium cations immobilize TFSI − and solvent molecules by ion–dipole interactions, which accelerate the dissociation of LiTFSI and Li + desolvation. Moreover, the monodispersed zwitterionic units coupling with ordered micropore structures in Z-COF create exclusive Li + migration channels, modulate homogeneous space charge distribution, kinetically facilitating uniform Li + deposition. Experiments and theoretical calculations indicate that C–F and S–N bonds of TFSI − exhibit enhanced cleavage susceptibility driven by electrostatic attraction, realizing a LiF/Li 3 N-rich electrolyte/electrode interface. The designed Z-COF protection layer enables Li|Li symmetrical cells stable cycling over 6300 h at 2 mA cm −2 /2 mAh cm −2 . The Z-COF@Li|LiFePO 4 (LFP) full cells deliver high-capacity retention of 85.2% after 1000 cycles at 8 C. The assembled Z-COF@Li|LFP pouch cells demonstrate a lifespan of more than 240 cycles. This work provides fresh insights into the practical application of zwitterionic COF in next-generation LMBs.

Donor-π-acceptor (D-π-A) conjugated polymers are promising photocatalysts for water splitting. Their π-bridges promote intramolecular charge transfer (ICT), leading to better charge separation and enhanced activity. However, further improvements can be achieved by carefully choosing donor units and optimizing building block combinations. In this study, five conjugated porous polymers (CPPs) were synthesized via Still/Suzuki coupling reactions, including ternary polymers with varying donor-to-acceptor ratios and binary polymers for comparison. Photocatalytic hydrogen production (PHP) tests showed that the ternary polymer TATTS-1 achieved the highest hydrogen evolution rates (HER) of 130.56 and 172.75 mmol g^-1 h^-1 under visible light and full arc irradiation, respectively. Kelvin probe force microscopy (KPFM) and femtosecond transient absorption (fs-TA) spectroscopy measurements confirmed that the adoption of the D-π-A configuration can facilitate charge separation, suppress recombination, and enhance transfer efficency, which was also confirmed by theoretical calculations. These findings underscore the superior performance of the D-π-A configuration over conventional Donor-acceptor (D-A) systems in designing efficient polymer-based photocatalysts, and highlighting the synergy of triazatruxene (TAT) donor, thiophene π-bridge, and dibenzothiophene sulfone (BTDO) acceptor in building efficient hydrogen evolution photocatalysts.

Cellular oxidative stress, characterized by excessive reactive oxygen species (ROS) production, disrupts cellular homeostasis and induces pH fluctuations within cells and organelles. Given the critical role of intracellular pH in maintaining homeostasis and regulating vital processes such as proliferation and enzyme activity, we designed and synthesized the benzothiazole-based fluorescent probe LYB-OH for pH monitoring. LYB-OH exhibits notably large Stokes shifts across various solvents, particularly in water where the Stokes shift exceeded 200 nm. Additionally, LYB-OH possessed good selectivity, stability, and reversibility in vitro. In biological imaging, the probe LYB-OH displayed low cytotoxicity and good imaging ability for different pH in cells. Furthermore, the probe enabled the visualization of pH changes in both cells and zebrafish induced by hydrogen peroxide and lipopolysaccharide. This provided an idea for the diagnosis of related diseases caused by intracellular pH fluctuations under oxidative stress.