Advanced membranes that enable ultrafast water flux while demonstrating anti-biofouling characteristics can facilitate sustainable water/wastewater treatment processes. MXenes, two-dimensional (2D) metal carbides and nitrides, have attracted attention for applications in water/wastewater treatment. In this work, we reported the antibacterial properties of micrometer-thick titanium carbide (Ti3C2Tx) MXene membranes prepared by filtration on a polyvinylidene fluoride (PVDF) support. The bactericidal properties of Ti3C2Tx modified membranes were tested against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) by bacterial growth on the membrane surface and its exposure to bacterial suspensions. The antibacterial rate of fresh Ti3C2Tx MXene membranes reaches more than 73% against B. subtilis and 67% against E. coli as compared with that of control PVDF, while aged Ti3C2Tx membrane showed over 99% growth inhibition of both bacteria under same conditions. Flow cytometry showed about 70% population of dead and compromised cells after 24 h of exposure of both bacterial strains. The damage of the cell surfaces was also revealed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis, respectively. The demonstrated antibacterial activity of MXene coated membranes against common waterborne bacteria, promotes their potential application as anti-biofouling membrane in water and wastewater treatment processes.

Organic-inorganic lead-halide perovskites have received a revival of interest in the past few years as a promising class of materials for photovoltaic applications. Despite recent extensive research, the role of cations in defining the high photovoltaic performance of these materials is not fully understood. Here, we conduct nonadiabatic molecular dynamics simulations to study and compare nonradiative hot carrier relaxation in three lead-halide perovskite materials: CHNHPbI, HC(NH)PbI, and CsPbI. It is found that the relaxation of hot carriers to the band edges occurs on the ultrafast time scale and displays a strong quantitative dependence on the nature of the cations. The obtained results are explained in terms of electron-phonon couplings, which are strongly affected by the atomic displacements in the Pb-I framework triggered by the cation dynamics.

In the framework of the time-dependent Ginzburg-Landau formalism, we study the "resistive" state of a submicron superconducting stripe in the presence of a longitudinal current. Sufficiently strong current leads to phase slippage between the leads, which is manifested as oppositely charged kinematic vortices moving in opposite directions perpendicular to applied drive. Depending on the distribution of superconducting current density the vortex-antivortex either nucleate in the middle of the stripe and are expelled laterally or enter on opposite sides of the sample and are driven together to annihilation. We distinguish between the two scenarios as a function of relevant parameters and show how the creation/annihilation point of the vortex-antivortex and their individual velocity can be manipulated by applied magnetic field and current.

Role of surface termination on the dielectric and optical properties of Ti3C2T2 (T = F, O, OH) MXene is studied using first-principles density functional theory. The results show that the surface functionalization has a significant impact on the optical properties of the MXene. For example, in the visible range of the spectrum, the oxidized sample shows larger absorption, whereas surface fluorination results in weaker absorption as compared to pristine MXene. In the ultraviolet energy range, all functional groups lead to the enhancement of both absorption and reflectivity of the material. Dielectric properties of MXene are also sensitive to the surface functionalization. Our findings demonstrate the importance of surface termination on the optical properties of the MXene.