Provided are enhanced MXene materials made from MAX-phase precursors that comprise an excess of metal A. The resultant enhanced MXenes exhibit improved stability over periods of days and months, particularly when stored in aqueous media.

The invention generally relates to electrochemically active structures and methods of making thereof. More specifically, the invention relates to electrochemically active structure comprising a crystalline electride comprising a nitride or carbide of at least one of: an alkaline earth metal, a transition metal, a lanthanide metal, or a combination thereof, wherein the electride has a lattice capable of intercalating at least one ion, thereby releasing at least one electron into an external circuit; and wherein a change in lattice volume of the electride upon intercalating the at least one ion is less than about 40%. Further, methods of making these electrochemically active structures are disclosed. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

The invention generally relates to electrochemically active structures and methods of making thereof. More specifically, the invention relates to electrochemically active structure comprising a crystalline electride comprising a nitride or carbide of at least one of: an alkaline earth metal, a transition metal, a lanthanide metal, or a combination thereof, wherein the electride has a lattice capable of intercalating at least one ion, thereby releasing at least one electron into an external circuit; and wherein a change in lattice volume of the electride upon intercalating the at least one ion is less than about 40%. Further, methods of making these electrochemically active structures are disclosed. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Methods are disclosed for dispersing nanoparticles in solvents, involving the use of a cationic species and an anionic species, where at least one of the ionic species is soluble in the nonpolar solvent and the other ionic species has a relatively strong affinity for the surface of the nanoparticles. The cationic species and the anionic species together form a cluster of ion pairs shielding the nanoparticles and enhancing their dispersibility in the nonpolar solvent.

Methods are disclosed for dispersing nanoparticles in solvents, involving the use of a cationic species and an anionic species, where at least one of the ionic species is soluble in the nonpolar solvent and the other ionic species has a relatively strong affinity for the surface of the nanoparticles. The cationic species and the anionic species together form a cluster of ion pairs shielding the nanoparticles and enhancing their dispersibility in the nonpolar solvent.

An iron-carbon composite material and a preparation method thereof are disclosed. The iron-carbon composite material includes a three-layer core-shell structure, which successively includes a porous graphite carbon outer layer, an iron carbide intermediate layer and a nano zero-valent iron core from outside to inside. The present invention wraps nano zero-valent iron in porous graphite carbon and iron carbide, which can prevent the oxidation of nano zero-valent iron, while iron carbide effectively improves the ability to fix arsenic, realizing high efficiency and long-term use of nano zero-valent iron. Iron carbide may effectively adsorb and fix arsenic, and especially efficiently oxidize As(III) to relatively low-toxic As(V).

An iron-carbon composite material and a preparation method thereof are disclosed. The iron-carbon composite material includes a three-layer core-shell structure, which successively includes a porous graphite carbon outer layer, an iron carbide intermediate layer and a nano zero-valent iron core from outside to inside. The present invention wraps nano zero-valent iron in porous graphite carbon and iron carbide, which can prevent the oxidation of nano zero-valent iron, while iron carbide effectively improves the ability to fix arsenic, realizing high efficiency and long-term use of nano zero-valent iron. Iron carbide may effectively adsorb and fix arsenic, and especially efficiently oxidize As(III) to relatively low-toxic As(V).

MXene fibers and a preparation method thereof are provided. The method for preparation of a MXene fiber comprises preparing a dope solution in which MXene sheets are dispersed in a polar solvent, extruding the dope solution into a coagulating solution to coagulate the extruded dope solution to change into a MXene gel fiber, and drying the MXene gel fiber and converting it into the MXene fiber.

Systems and methods for converting metal oxide to metal using metal carbide as an intermediate, include: reacting the metal oxide with carbon to produce the metal carbide, wherein the metal carbide is in a form of powder or pellets; and subjecting the metal carbide produced from the metal oxide and the carbon to electrolysis in an electrorefiner to produce and purify the metal.

Systems and methods for converting metal oxide to metal using metal carbide as an intermediate, include: reacting the metal oxide with carbon to produce the metal carbide, wherein the metal carbide is in a form of powder or pellets; and subjecting the metal carbide produced from the metal oxide and the carbon to electrolysis in an electrorefiner to produce and purify the metal.