RÉSUMÉ
As a novel electrochemical energy conversion device, direct ethanol fuel cells are currently encountering two significant challenges: CO poisoning and the difficulty of C-C bond cleavage in ethanol. In this work, an amorphous PdS nanowires/ultrafine IrMnOx bimetallic oxides (denoted as a-PdS/IrMnOx NWs) catalyst with abundant oxide/metal (crystalline/amorphous) inverse heterogeneous interfaces was synthesized via a hydrothermal process succeeded by a nonthermal air-plasma treatment. This unique interfacial electronic structure along with the incorporation of oxyphilic metal has resulted in a significant enhancement in the electrocatalytic performance of a-PdS/IrMnOx NWs toward the ethanol oxidation reaction, achieving current densities of 12.45 mA·cm-2 and 3.68 A·mgPd-1. Moreover, the C1 pathway selectivity for ethanol oxidation has been elevated to 47%, exceeding that of other as-prepared Pd-based counterparts and commercial Pd/C catalysts. Density functional theory calculations have validated the findings that the decoration of IrMn species onto the amorphous PdS surface has induced a charge redistribution in the interface region. The redistribution of surface charges on the a-PdS/IrMnOx NWs catalyst results in a significant decrease in the activation energy required for C-C bond cleavage and a notable weakening of the CO binding strength at the Pd active sites. Consequently, it enhanced both the EOR C1 pathway selectivity and CO poisoning resistance to the a-PdS/IrMnOx NWs catalyst.
RÉSUMÉ
Antibiotic tolerance is implicated in difficult-to-treat infections and the development and spread of antibiotic resistance. The high storage capacities and excellent biocompatibilities of UiO-66-based metal-organic frameworks (MOFs) have made them emerging candidates as drug-delivery vectors. In view of hydrogen sulfide (H2S) having been associated with the development of intrinsic resistance to antibacterial agents, we designed a strategy to potentiate existing antibiotics by eliminating bacterial endogenous H2S. We efficiently fabricated an antibiotic enhancer Gm@UiO-66-MA to remove bacterial H2S and sensitize an antibacterial by modifying UiO-66-NH2 with maleic anhydride (MA) and then loading it with gentamicin (Gm). UiO-66-MA achieved the removal of bacterial endogenous H2S and the destruction of bacterial biofilm by selectively undergoing Michael addition with H2S. Moreover, Gm@UiO-66-MA further enhanced the susceptibility of tolerant E. coli to Gm after reducing bacterial intracellular H2S levels. An in vivo skin wound healing experiment confirmed that Gm@UiO-66-MA could greatly reduce the risk of bacterial reinfection and accelerate wound healing. Overall, Gm@UiO-66-MA offers a promising antibiotic sensitizer for minimizing bacterial resistance and a therapeutic strategy for tolerant bacteria-related refractory infections.
