Self-redox reaction driven in situ formation of Cu2O/Ti3C2Tx nanosheets boost the photocatalytic eradication of multi-drug resistant bacteria from infected wound.

BACKGROUND: MXenes with interesting optical and electrical properties have been attractive in biomedical applications such as antibacterial and anticancer agents, but their low photogeneration efficiency of reactive oxygen species (ROS) and poor stability are major concerns against microbial resistance. METHODS: Water-dispersible single layer Ti3C2Tx-based MXene through etching tightly stacked MAX phase precursor using a minimally intensive layer delamination method. After addition of Cu(II) ions, the adsorbed Cu(II) ions underwent self-redox reactions with the surface oxygenated moieties of MXene, leading to in situ formation of Cu2O species to yield Cu2O/Ti3C2Tx nanosheets (heterostructures). RESULTS: Under NIR irradiation, the Cu2O enhanced generation of electron-hole pairs, which boosted the photocatalytic production of superoxide and subsequent transformation into hydrogen peroxide. Broad-spectrum antimicrobial performance of Cu2O/Ti3C2Tx nanosheets with sharp edges is attributed to the direct contact-induced membrane disruption, localized photothermal therapy, and in situ generated cytotoxic free radicals. The minimum inhibitory concentration of Cu2O/Ti3C2Tx nanosheets reduced at least tenfold upon NIR laser irradiation compared to pristine Cu2O/Ti3C2Tx nanosheets. The Cu2O/Ti3C2Tx nanosheets were topically administrated on the methicillin-resistant Staphylococcus aureus (MRSA) infected wounds on diabetic mice. CONCLUSION: Upon NIR illumination, Cu2O/Ti3C2Tx nanosheets eradicated MRSA and their associated biofilm to promote wound healing. The Cu2O/Ti3C2Tx nanosheets with superior catalytic and photothermal properties have a great scope as an effective antimicrobial modality for the treatment of infected wounds.

Robust and Intimate Interface Enabled by Silicon Carbide as an Additive to Anodes for Lithium Metal Solid-State Batteries.

Garnet-type solid-state electrolytes are among the most reassuring candidates for the development of solid-state lithium metal batteries (SSLMB) because of their wide electrochemical stability window and chemical feasibility with lithium. However, issues such as poor physical contact with Li metal tend to limit their practical applications. These problems were addressed using ß-SiC as an additive to the Li anode, resulting in improved wettability over Li6.75 La3 Zr1.75 Ta0.25 O12 (LLZTO) and establishing an improved interfacial contact. At the Li-SiC|LLZTO interface, intimacy was induced by a lithiophilic Li4 SiO4 phase, whereas robustness was attained through the hard SiC phase. The optimized Li-SiC|LLZTO|Li-SiC symmetric cell displayed a low interfacial impedance of 10â€…Ω cm2 and superior cycling stability at varying current densities up to 5800 h. Moreover, the modified interface could achieve a high critical current density of 4.6 mA cm-2 at room temperature and cycling stability of 1000 h at 3.5 mA cm-2 . The use of mechanically superior materials such as SiC as additives for the preparation of a composite anode may serve as a new strategy for robust garnet-based SSLMB.