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• MgAl and ZnAl LDHs are prepared via hydrothermal route. • Antimicrobial photodynamic therapy properties of LDHs are studied by using fluorescence spectroscopy. • Yb doped ZnAl LDHs showed the best antibacterial activity. Layered double hydroxides (LDHs) belong to a class of 2D nanomaterials having metallic ions of varying valences and interlayer spacing as in brucite. Since their discovery, they are being used everywhere. However, their biomedical properties are the most explored as they exhibit advantages like biodegradability, biocompatibility, and ease of making composites. In this research, two types of LDHs i.e. Mg Al and Zn Al LDHs are synthesized via hydrothermal route. Two types of doping; Gd and Yb, are done to create Gd Mg Al, Gd Zn Al, Yb Mg Al and Yb Zn Al. After synthesis, LDHs are characterized by X-ray Diffraction, Scanning Electron Microscopy, Dynamic Light Scattering, Energy dispersive X-ray Spectroscopy, and UV–vis spectroscopy. Average length for LDHs was found out to be in the range of 275–467 nm whereas thickness was in between 67 nm and 135 nm via SEM. Hydrodynamic size came out to be between 331 nm and 1720 nm for all samples. Absorption wavelength for all samples was between 251 and 261 nm. A novel antibacterial approach utilizing LDHs was introduced, employing antibacterial photodynamic treatment. The results were quantified using fluorescence spectroscopy, taking tryptophan peak as bacterial indicator at 270 nm excitation. Spectra recorded in 285–550 nm range showed considerable bacterial degradation, notably with Yb Zn Al LDHs. The efficacy was further tested with Colony Forming Units. Notably, all synthesized particles outperformed UV light alone, demonstrating their versatility as photocatalysts for bacterial inactivation. This pioneering method provides a unique and effective strategy for antibacterial treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights • PEGlyated-Porous Alumina Whiskers (PAW) were developed via hydrothermal route. • PEGlyated-PAW showed excellent biocompatibility in Rhabdomyosarcoma (RD) cell line. • PEGylated-PAW demonstrates promising drug loading & release characteristics. Abstract This study reports the fabrication and potential evaluation of Porous Alumina Whiskers (PAW) synthesized by facile two-step process, hydrothermal synthesis followed by calcination, for drug delivery applications. The as-synthesized PAW were modified with Polyethylene Glycol (PEG), after hydroxylation, to improve biocompatibility. Chemical and structural properties of Porous Alumina Whiskers (PAW) were evaluated by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) which confirm the successful synthesis of PEGylated PAW. Moreover, biocompatibility was accessed via MTT-assay using Rhabdomyosarcoma cell line. Finally drug loading and release capabilities of PEGylated PAW were tested using photosense, a standard photodynamic therapy (PD) model drug. Results confirm the suitability of PAW as a potential platform for drug delivery. [ABSTRACT FROM AUTHOR]

Herein, 3D flower-like δ-MnO 2 , MXene and δ-MnO 2 /MXene in-situ hybrid (IH) composites were prepared (via hydrothermal and solution treatment methods) for the effective removal of Cr (VI) from the contaminated water. The effect of various experimental parameters including contact time, pH levels and initial Cr (VI) ions concentration was determined and compared under static conditions. The kinetics of Cr (VI) adsorption onto δ-MnO 2 , MXene, and IH confirmed the existence of a pseudo-second-order model. The obtained results reveal that the removal of Cr (VI) largely depends on the pH of the solution. The adsorption isotherm data fits best for Freundlich model, illustrating a multi-site adsorption mechanism of Cr (VI) ion on these adsorbents. The maximum Cr (VI) adsorption capacities onto δ-MnO 2 , MXene and IH are 235.65 mg g−1, 273.1 mg g−1 and 353.87 mg g−1, respectively. The study reveals that hetero-engineered approach of synthesizing transition metal oxides with MXenes provides abundant opportunities to remove contaminants from water with better efficiency due to reduction and electrostatic interaction. [ABSTRACT FROM AUTHOR]

Herein, we report terahertz (THz) shielding of flexible MXene (Ti3C2Tx)/MWCNT/PVA polymer composite films by using THz time-domain spectroscopy (THz-TDS) in 0.1–2.0 THz frequency range. The polymer composite with 42 µm thickness exhibited an excellent shielding effectiveness of 36 dB at 2 THz which is much higher than most of the reported materials for THz shielding with comparable thickness. The absorption coefficient increases from 100 cm−1 for pristine PVA to ~ 600 cm−1 for 20 wt% MXene/1.5 wt% MWCNT/PVA composite. The high THz shielding of flexible MXene/MWCNT/polymer composite is ascribed to the good electrical conductivity and interfacial synergistic effect of 1D/2D nanostructures that promoted the shielding of electromagnetic waves. Our simple solution casting methodology for fabrication of thin films and subsequent high THz shielding opens possibilities to design MXene-based polymer composites for THz applications. [ABSTRACT FROM AUTHOR]

Industrial utilization of nuclear resources greatly depends on the effective treatment of nuclear waste. The efficient removal of radioactive nuclides from liquid effluents by using different adsorbents has thus become crucial. Herein, for the first time, two-dimensional transition metal carbides (MXenes) are investigated as scavengers of cesium (Cs+) from contaminated water. Due to the combined advantages of the layered structure and the presence of heterogeneous sites (hydroxyl, oxygen and fluorine groups), the adsorbent reached the steady state within 1 min with the maximum Cs+ adsorption capacity of 25.4 mg g−1 at room temperature. The kinetics studies of the Cs+ scavenging process demonstrated that the adsorption of Cs+ followed the pseudo-second-order model whereas the adsorption equilibrium data obeyed the Freundlich model. Thermodynamic studies revealed that the adsorption process was endothermic. The adsorbent showed an excellent Cs+ removal efficiency in neutral to slightly alkaline solutions. Moreover, it can retain Cs+ even in the presence of a high concentration of competing cations (Li+, Na+, K+, Mg2+ and Sr2+). The Cs+ loaded adsorbent was regenerated with a 0.2 M HCl solution and reused at least five times for over 91% removal of contaminants. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D material coated polyurethane foam has been prepared first time for water treatment. • The synthesis method is green, facile and scalable. • The proposed adsorbent revealed excellent uptake potential towards Pb2+. Herein, for the first time, highly efficient, inexpensive, lightweight, and ecofriendly MXene coated polyurethane foam (PUF) have been prepared for the dynamic uptake of Pb2+ from water in a fixed bed column. The Pb2+ ions were adsorbed on the negatively charged MXene via electrostatic interaction and ion exchange mechanism. A series of fixed bed column studies were carried out using continuously flowing feed solution and the PUF samples coated with three alternate layers of MXene and Chitosan (CS) showed the highest adsorption capacity i.e., 80% Pb2+ removal in first 20 min and >40% removal even after 3 h where initial concentration was 4 ppm. [ABSTRACT FROM AUTHOR]