▎ 摘　　要

NOVELTY - Hollow MXn-based metal oxide composite material comprises V2CTxMXenes, reducing graphene oxide and metal oxide as main components of the material under the condition of solvent thermal method, realizing reduction of graphene oxide and V2CTxMXenes electrostatic self-assembly to obtain V2CTx/rGO MXenes, and realizing the metal oxide in V2CTx/rGO MXenes surface growth, to obtain the hollow MXnbased metal oxide composite material, the V2CTxMXenes through the substrate material through etching agent, expanding agent and ionic liquid treatment, in accordion shape as carrier of the composite material, the ionic liquid in solvent heat process to protect the V2CTxMXenes sheet structure is not oxidized and acts as (nickel molybdate) NiMoO4 structure guiding agent, reducing graphene oxide is intermediate layer material having 3 functions, and one is the function of connecting V2CTxMXenes and metal oxide. USE - Used as hollow MXn-based metal oxide composite material. ADVANTAGE - The composite material: uses the non-constant centrifugal condition and the ion liquid to adjust and control the microcosmic appearance. as the application of the super capacitor, charging and discharging in the range of -0.2 to -0.35V, when the discharge current density is 1 A/g, the specific capacitance is 1000- 1100 F/g, after 3000 cycles of the current density of 10 A/g, the specific capacitance performance can still reach the original 88-89% of the original one and has excellent electrochemical characteristic and chemical stability. DETAILED DESCRIPTION - Hollow MXn-based metal oxide composite material comprises V2CTxMXenes, reducing graphene oxide and metal oxide as main components of the material under the condition of solvent thermal method, realizing reduction of graphene oxide and V2CTxMXenes electrostatic self-assembly to obtain V2CTx/rGO MXenes, and realizing the metal oxide in V2CTx/rGO MXenes surface growth, to obtain the hollow MXnbased metal oxide composite material, the V2CTxMXenes through the substrate material through etching agent, expanding agent and ionic liquid treatment, in accordion shape as carrier of the composite material, the ionic liquid in solvent heat process to protect the V2CTxMXenes sheet structure is not oxidized and acts as (nickel molybdate) NiMoO4 structure guiding agent, reducing graphene oxide is intermediate layer material having 3 functions, one is the function of connecting V2CTxMXenes and metal oxide, inhibiting the stack between V2CTxMXenes layer and layer, inducing the growth of metal oxide, forming petal fold-shaped structure, the component of the metal oxide is NiMoO4, the shape is petal fold-shaped structure through the distribution on the V2CTx/(reduced graphene oxide) rGO MXenes surface two-dimensional space for fast faraday reaction, providing the function of pseudo-capacitance, the composite material having three components, the micro-topography has a hollow structure, nickel, molybdenum, oxygen and nitrogen elements are uniformly distributed in the V2CTxMXgraphene sheet structure on the outer surface, the C element forms an annular structure to surround the material together, namely, the carbon shell is embedded to form a hollow structure. INDEPENDENT CLAIMS are also included for: (1) preparing hollow MX-based metal oxide composite material, comprising (i) preparing multi-layer MXenes powder, placing the V2AlC MAX powder material in the hydrogen fluoride aqueous solution for stirring, then performing the first centrifugal operation with centrifugal condition, then performing the second centrifugal operation with centrifugal condition, and repeating the second centrifugal operation for a certain number of times, making the pH of the solution reach a certain standard, freezing and drying the precipitate obtained after centrifuging to obtain multi-layer MXenes powder, (ii) preparing accordion small layer V2CTxMXenes under, dispersing multilayer M-Xenes powder obtained in step (i) into tetrabutyl ammonium hydroxide solution for stirring, then performing the third centrifugal operation with a certain centrifugal condition, and repeating the third centrifugal operation for a certain number of times, freezing and drying precipitate obtained after centrifuging to obtain the accordion-shaped small layer V2CTxMXenes, and (iii) preparing hollow MXenes metal oxide composite material, uniformly mixing the ionic liquid 1-butyl-3-methyl imidazole tetrafluoroborate and de-ionized water, continuously adding nickel nitrate, sodium molybdate in an amount of a certain substance, urea stirring to completely dissolve, then adding V2CTxMXenes and graphene oxide aqueous solution, uniformly mixing into the solution, stirring, subjecting the mixed solution to solvent thermal reaction, cooling, washing and drying the obtained product; and (2) use of hollow MXn-based metal oxide composite material as a super capacitor, charging and discharging in the rate of -0.2 to -0.35 V, when the discharge current density is 1 A/g, and the specific capacitance is 1000-1100 F/g.