Xueyan Zhang

Development of bioadsorbents for efficient removal of heavy metal ions from contaminated water is of great interest but still challenging. In this study, a 1,2,4-triazole-3-thiol modified lignin-based adsorbent (LBA) was synthesized through a UV-initiated thiol-yne click reaction chemistry for Cd(II) adsorption. The structure of LBA, prepared by thiol-yne addition reaction, was confirmed and characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and elemental analysis. Effects of pH, contact time, initial metal concentration, and temperature on the adsorption of Cd(II) on LBA were studied. Due to multiple thio-triazole units as binding sites, LBA was found to exhibit an adsorption capacity that was 8.6 times that of the raw lignin for Cd(II) adsorption. Pseudo-second-order and Langmuir models were utilized to describe the adsorption kinetics and isotherms, respectively. Furthermore, the study of adsorption selectivity suggested that LBA had high selectivity for adsorbing Cd(II) ions in the presence of other coexisting metal ions in the aqueous solution. The successful synthesis of LBA via a facile thiol-yne click reaction demonstrates a new synthesis method for preparing lignin-based functional materials with modular units and promising adsorption capacity for the removal of heavy metal ions from wastewater.

Supramolecular nanomedicines have shown great merits in cancer therapy, but their clinical translation is hampered by monotonous therapeutic modality and unsatisfactory antitumor performance. Herein, a hybrid supramolecular polymeric nanomedicine (SNPs) is developed based on β-cyclodextrin/camptothecin (CPT) host-guest molecular recognition and iron-carboxylate coordination. Iron ions stabilizing SNPs catalyze the conversion of intracellular hydrogen peroxide into highly toxic hydroxyl radical through a Fenton reaction, which further cleaves the thioketal linker of the supramolecular monomer to release potent CPT, thus amplifying the therapeutic efficacy by combining chemodynamic therapy and chemotherapy. The combination therapy stimulates antitumor immunity and promotes intratumoral infiltration of cytotoxic T lymphocytes by triggering immunogenic cell death. In synergy with PD-L1 checkpoint blockade, SNPs enables enhanced immune therapy and a long-term tumor remission.

Supramolecule self-assembly of dicyandiamide and uracil followed by thermal polymerization route is designed to prepare carbon atom self-doped g-C3N4 (CCNx), and then wet reduction is applied to fabricate Pd single atoms (Pd1) and nanoparticles (PdNPs) co-anchored CCNx heterojunctions (Pd1+NPs/CCNx). In Pd1+NPs/CCNx structure, interlayer Pd−N4 coordination is the most favorable for chemically stabilizing Pd1, while PdNPs accumulate on the in-plane of CCNx. Pd1+NPs/CCNx heterojunctions exhibit remarkably enhanced photocatalytic H2 evolution reaction (HER) activity, and HER rate and AQY value reach up to 24.1 mmol g−1 h−1 and 17.1% (400 nm) over the optimized Pd1+NPs/CCNx catalyst. Mechanism studies unveil that synergy of as-built interlayer N−Pd−N electron transfer channels at the atomic-scale and surface Mott–Schottky effect of small Pd nanoparticles notably accelerates migration of photogenerated electrons, which leads to plentiful electrons accumulation around Pd single atoms and small nanoparticles to decrease the energy barrier of H* activation and boost HER photodynamics significantly.