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MXenes are a group of inorganic two-dimensional (2D) nanomaterial, and have raised significant interests in biomedical areas. Ti3C2T x, as an important member of MXene family, is widely studied because of its biodegradability and low-cytotoxicity. However, their single antibacterial mechanism and poor stability in aqueous solution need to be improved, especially for the antimicrobial applications. In this work, a MXene-based hybrid antibacterial system (M-HAS) was developed and its synergistic antibacterial activity was investigated. In the M-HAS, 2D few-layer Ti3C2T x (FL-Ti3C2T x) was modified with hydrophilic polymers and thereby used as carriers for silver nanoparticles (Ag NPs). By assembling these two substrates, photodynamic performance of the prepared system is significantly improved with a large amount of reactive oxygen species produced under 660 nm laser. Antibacterial effects of the M-HAS are enhanced by over 4 times with irradiation. In another word, the developed hybrid system displays excellent photodynamic antibacterial synergistic properties. This work takes advantage of the photodynamic properties of each component in the M-HAS to achieve efficient antibacterial activity and proposes an innovative approach to develop the 2D FL-Ti3C2T x -based antibacterial platform. [ABSTRACT FROM AUTHOR]

In this work, the hierarchical NiCo2O4 self-assembled by lamellar flakes were successfully synthesized by a simple solvothermal route and subsequent thermal treatment. The composition and microstructure of the hierarchical NiCo2O4 were characterized by XRD and SEM, respectively. The microwave absorption properties were also evaluated. An optimum reflection loss (RL) of − 45.5 dB at 4.6 GHz with a composite thickness of 4.2 mm and effective bandwidth (RL < − 10 dB) of 7.7 GHz were obtained. The excellent electromagnetic wave absorption property of the hierarchical NiCo2O4 is due to the conduction loss and dielectric loss of NiCo2O4, the hierarchical structure could also enhance the microwave absorbing properties by the strong multi-reflections and scattering of microwave between stacking layers. [ABSTRACT FROM AUTHOR]

Highly efficient three-dimensional (3D) kaolinite/MnO 2 -CuO (KM@CuO-NO 3 ) catalysts were synthesized by a mild biomimetic strategy. Kaolinite flakes were uniformly wrapped by ultrathin tremelliform MnO 2 nanosheets with thicknesses of around 1.0-1.5 nm. Si-O and Al-O groups in kaolinite hosted MnO 2 nanosheets to generate a robust composite structure. The ultrathin MnO 2 lamellar structure exhibited excellent stability even after calcination above 350 °C. Kaolinite/MnO 2 exhibited abundant edges, sharp corners, and interconnected diffusion channels, which are superior to the common stacked structure. Open channels guaranteed fast transportation and migration of CO and O 2 during CO oxidation. The synthesized KM@CuO-NO 3 achieved a 90% CO conversion efficiency at a relatively low temperature (110 °C). Furthermore, the abundant oxygen vacancies on KM@CuO-NO 3 assisted the adsorption and activation of oxygen species and thus enhanced the oxygen mobility and reactivity in the catalytic process. The mechanism results suggest that CuO introduced to the catalyst not only acted as CO active sites but also weakened the Mn-O bond, subsequently improved the mobilities of the oxygen species, which was found to contribute to its high activity for CO oxidation. This study provides new conceptual insights into rationally regulating structural assembly between transition metal oxides and natural minerals for high-performance catalysis reactions.