An electrode comprising a space group Pna2.sub.1 VOPO.sub.4 lattice, capable of electrochemical insertion and release of alkali metal ions, e.g., sodium ions. The VOPO.sub.4 lattice may be formed by solid phase synthesis of KVOPO.sub.4, milled with carbon particles to increase conductivity. A method of forming an electrode is provided, comprising milling a mixture of ammonium metavanadate, ammonium phosphate monobasic, and potassium carbonate; heating the milled mixture to a reaction temperature, and holding the reaction temperature until a solid phase synthesis of KVOPO.sub.4 occurs; milling the KVOPO.sub.4 together with conductive particles to form a conductive mixture of fine particles; and adding binder material to form a conductive cathode. A sodium ion battery is provided having a conductive NaVOPO.sub.4 cathode derived by replacement of potassium in KVOPO.sub.4, a sodium ion donor anode, and a sodium ion transport electrolyte. The VOPO.sub.4, preferably has a volume greater than 90 ?.sup.3 per VOPO.sub.4.

A preparation method of a tetragonal NaV.sub.2O.sub.5.H.sub.2O nanosheet-like powder includes steps of: (S1) simultaneously adding NaVO.sub.3 and Na.sub.2S.9H.sub.2O into deionized water, and then magnetically stirring, and obtaining a black turbid solution; (S2) sealing after putting the black turbid solution into an inner lining of a reaction kettle, fixing the sealed inner lining in an outer lining of the reaction kettle, placing the reaction kettle into a homogeneous reactor, and then performing a hydrothermal reaction; and (S3) after completing the hydrothermal reaction, naturally cooling the reaction kettle to the room temperature, and then alternately cleaning through water and alcohol, and then collecting a product, drying the product, and finally obtaining the tetragonal NaV.sub.2O.sub.5.H.sub.2O nanosheet-like powder with a thickness in a range of 30-60 nm and a single crystal structure grown along a (002) crystal orientation.

Nanoplatelet forms of metal hydroxide and metal oxide are provided, as well as methods for preparing same. The nanoplatelets are suitable for use as fire retardants and as agents for chemical or biological decontamination.

Nanoplatelet forms of metal hydroxide and metal oxide are provided, as well as methods for preparing same. The nanoplatelets are suitable for use as fire retardants and as agents for chemical or biological decontamination.

Electrochemical cell comprising an anode and a cathode is provided. The anode and the cathode independently comprises or consists essentially of a vanadium oxide compound having general formula M.sub.nV.sub.6O.sub.16, wherein M is selected from the group consisting of ammonium, alkali-metal, and alkaline-earth metal; and n is 1 or 2. Method of preparing a vanadium oxide compound having general formula M.sub.nV.sub.6O.sub.16 is also provided.

Electrochemical cell comprising an anode and a cathode is provided. The anode and the cathode independently comprises or consists essentially of a vanadium oxide compound having general formula M.sub.nV.sub.6O.sub.16, wherein M is selected from the group consisting of ammonium, alkali-metal, and alkaline-earth metal; and n is 1 or 2. Method of preparing a vanadium oxide compound having general formula M.sub.nV.sub.6O.sub.16 is also provided.

According to one embodiment, an active material including a composite oxide is provided. The composite oxide has a monoclinic crystal structure and is represented by the general formula Li.sub.wM1.sub.2xTi.sub.8yM2.sub.zO.sub.17+, wherein: M1 is at least one selected from the group consisting of Cs, K, and Na; M2 is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Fe, Co, Mn, and Al; 0w10; 0<x<2; 0<y<8; 0<z<8; and 0.50.5.

A device including an LED light source optically coupled to a green-emitting U.sup.6+-doped phosphor having a composition selected from the group consisting of U.sup.6+-doped phosphate-vanadate phosphors, U.sup.6+-doped halide phosphors, U.sup.6+-doped oxyhalide phosphors, U.sup.6+-doped silicate-germanate phosphors, U.sup.6+-doped alkali earth oxide phosphors, and combinations thereof, is presented. The U.sup.6+-doped phosphate-vanadate phosphors are selected from the group consisting of compositions of formulas (A1)-(A12). The U.sup.6+-doped halide phosphors are selected from the group consisting of compositions for formulas (B1)-(B3). The U.sup.6+-doped oxyhalide phosphors are selected from the group consisting of compositions of formulas (C1)-(C5). The U.sup.6+-doped silicate-germanate phosphors are selected from the group consisting of compositions of formulas (D1)-(D11). The U.sup.6+-doped alkali earth oxide phosphors are selected from the group consisting of formulas (E1)-(E11).

Making a MAX phase material having a composition represented by V.sub.2PC includes combining a transition metal component, a phosphorus component, and a carbon component to yield a mixture, heating the mixture to yield a gel, and heating the gel to yield the MAX phase material. wherein the MAX material has a composition represented by V.sub.2PC. The transition metal component includes vanadium, the phosphorus component includes phosphoric acid, and the carbon component includes an organic compound. The MAX phase material can be in the form of a film, microsphere, or microwire.

The subject invention pertains to the synthesis and characterization of V.sub.2O.sub.5/CdE NW/QD heterostructures. The V.sub.2O.sub.5/CdE heterostructures are versatile new materials constructs for light harvesting, charge separation, and the photocatalytic production of solar fuels; polymorphism of V.sub.2O.sub.5 and compositional alloying of both components provides for a substantial design space for tuning of interfacial energy offsets. Also provided are a new class of type-II heterostructures composed of cadmium chalcogenide QDs (CdE where E=S, Se, or Te) and ?-V.sub.2O.sub.5 nanowires (NWs). The synthesis and characterization of V.sub.2O.sub.5/CdE NW/QD heterostructures, prepared via successive ionic layer adsorption and reaction (SILAR) and linker-assisted assembly (LAA), the characterization of their photoinduced charge-transfer reactivity using transient absorption spectroscopy, and their performance in the photocatalytic reduction of protons to hydrogen are also disclosed.