CN116354420B - A rutile high entropy oxyfluoride material and its preparation method and application - Google Patents

Abstract

The invention belongs to the technical field of high-entropy materials, and particularly relates to a rutile type high-entropy oxyfluoride material, and a preparation method and application thereof. The chemical composition formula of the rutile type oxyfluoride material is [ M (IV) O ₂]_x[M(Ⅱ)F₂]_y, wherein M (IV) is any one of Ti, sn, mo, W, mn, ru, ir, pb, ge, and M (II) is at least three of Mg, mn, zn, co, fe, ni, cu; the molar ratio of each metal element to all metal elements is 5% -35%, the molar ratio of oxygen to fluorine is 1:3-3:1, and the molar ratio of any two metal elements in M (II) is 1:2-2:1. The preparation method of the rutile type high-entropy oxyfluoride material is simple and controllable, low in cost and high in yield, and the material has the advantages of uniform element distribution, single crystal phase structure and good electrocatalytic water decomposition performance.

Description

A rutile high entropy oxyfluoride material and its preparation method and application

Technical Field

The invention belongs to the technical field of high entropy materials, and in particular relates to a rutile high entropy oxyfluoride material and a preparation method and application thereof.

Background technique

As a new type of material system developed in recent years, high entropy materials have attracted widespread attention. The premise of high entropy materials is to introduce high configurational entropy to stabilize the single-phase structure. Since Ye Junwei and others proposed the concept of high entropy in 2004, different types of high entropy materials, such as high entropy alloys, oxides, fluorides, sulfides, metal-organic framework structures, etc. have been synthesized one after another (Sci. Adv., 2021, 7, eabg1600). Due to the unique properties brought about by their unique high entropy effect, lattice distortion effect, hysteresis diffusion effect and cocktail effect, these high entropy materials have shown great advantages and application prospects in the fields of thermoelectricity, energy storage and conversion, thermal catalysis, electrocatalysis, etc. (Science, 2022, 376, eabn3103).

Oxyfluoride materials have excellent chemical and thermal stability, high electronic conductivity and strong electronegativity, and have shown excellent performance in catalysis, lithium-ion batteries and other fields (Angew. Chem. Int. Ed. 2021, 60, 9953-9958; Adv. Mater., 2011, 23, 2300-2305; Chem. Rev., 2015, 115, 1191-1254). High-entropy oxides and high-entropy fluorides have shown better reaction performance than single oxides and fluorides in terms of electrocatalysts for electrolysis of water to produce oxygen (J. Am. Chem. Soc., 2020, 142, 4550-4554; Adv. Funct. Mater., 2021, 31). Therefore, high-entropy oxyfluoride materials can fully utilize the respective advantages of oxides and fluorides while combining the unique advantages of high-entropy materials to form a synergistic enhancement effect of multiple cations and multiple anions, providing multifunctional active sites for the electrocatalytic water decomposition process, improving catalytic activity and stability, and surpassing the performance of traditional oxyfluorides. In 2021, Sheng Dai, Shize Yang and others synthesized perovskite-type high-entropy oxyfluoride solid solutions (Angew. Chem. Int. Ed., 2021, 60, 9953-9958), but there have been no reports of rutile-type high-entropy oxyfluoride materials. In order to meet the demand for new energy materials, it is urgent to explore more cheap, efficient and stable high-entropy oxyfluoride material systems and further develop their potential application areas.

Summary of the invention

The purpose of the present invention is to provide a rutile high entropy oxyfluoride material and a preparation method and application thereof in order to solve the above problems.

In order to achieve the above object, the technical solution of the present invention is as follows:

On one hand, the present invention provides a rutile high entropy oxyfluoride material, wherein the chemical composition formula of the rutile high entropy oxyfluoride material is [M(IV)O ₂ ] _x [M(II)F ₂ ] _y , wherein M(IV) is any one of Ti, Sn, Mo, W, Mn, Ru, Ir, Pb, and Ge, and M(II) is at least three of Mg, Mn, Zn, Co, Fe, Ni, and Cu; the molar percentage of each metal element in all metal elements is 5% to 35%, the molar ratio of oxygen to fluorine is 1:3 to 3:1, and the molar ratio of any two metals in each metal element of M(II) is 1:2 to 2:1.

Another aspect of the present invention provides a method for preparing the above-mentioned rutile high entropy oxyfluoride material, the preparation method comprising the following steps:

(1) according to the chemical composition of the rutile high entropy oxyfluoride material, adding the rutile single-phase metal oxide and the fluoride into a ball mill respectively;

(2) The above-mentioned rutile single-phase metal oxide and fluoride are mixed and ball-milled.

In the above technical scheme, further, in step (1), the single-phase metal oxide is any one of the oxides of Ti, Sn, Mo, W, Mn, Ru, Ir, Pb, and Ge, and the single-phase metal fluoride is at least three of the fluorides of Mg, Mn, Zn, Co, Fe, Ni, and Cu.

In the above technical solution, further, in step (2), the ball milling speed is 200 to 700 rpm/min, and the ball milling time is 1 to 24 hours.

In the above technical solution, further, in step (2), the ball-to-material ratio is 5:1 to 60:1.

In another aspect, the present invention provides an application of the above-mentioned rutile high-entropy oxyfluoride material in electrocatalytic water decomposition.

The present invention has the following beneficial effects:

1. The present invention synthesizes a rutile high-entropy oxyfluoride material, which has uniform element distribution and a single crystal phase structure. Compared with single metal oxyfluorides, it has the advantages of high chemical and thermal stability, high electronic conductivity, and strong electronegativity.

2. The metal types in the rutile high entropy oxyfluoride material of the present invention are easy to adjust, and can be components of different types, numbers and proportions, and the preparation method is simple and controllable, low in cost and high in yield.

3. The rutile high entropy oxyfluoride material of the present invention has good electrocatalytic water decomposition performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is the XRD characterization results of samples of Example 1, Example 2, Example 3 and Comparative Example 1;

FIG. 2 is the LSV curves of the rutile high entropy oxyfluoride obtained in Example 1 and the comparative example sample in the electrocatalytic water decomposition and oxygen evolution reaction.

Detailed ways

The following is a detailed description of the entire material preparation process through examples, but the scope of the claims of the present invention is not limited by these examples. At the same time, the examples only provide some conditions for achieving this purpose, but do not mean that these conditions must be met to achieve this purpose.

Unless otherwise specified, the materials used in the embodiments of the present invention can be obtained through commercial channels or prepared according to conventional methods well known to those skilled in the art.

The materials of Examples 1-8 of the present invention were tested by the following instruments and methods:

The structural information of the embodiment is analyzed by X-ray diffraction (XRD);

The electrocatalytic performance of the materials was evaluated by linear sweep voltammetry (LSV).

Examples 1-3 are for adjusting the type of rutile oxide; Examples 4-5 are for adjusting the ratio of metal oxide to fluoride; Examples 6-7 are for changing the ratio of metal fluoride; and Example 8 is for changing the ball milling speed and time.

Example 1

(1) 500 mg RuO ₂ , 19.5 mg MgF ₂ , 32.3 mg ZnF ₂ , 30.3 mg CoF ₂ , and 29.1 mg MnF ₂ were placed in a zirconia ball mill;

(2) The high entropy oxyfluoride [RuO ₂ ] ₃ [Mg _0.25 Zn _0.25 Co _0.25 Mn _0.25 F 2 ] 1 was obtained by ball milling to form a solid solution with _a ball-to-material ratio of 30:1, a ball milling time of 6 h, _and a rotation speed of 600 rpm/min.

Example 2

(1) Place 500 mg MnO ₂ , 20.3 mg MgF ₂ , 33.7 mg ZnF ₂ , 31.6 mg CoF ₂ , and 30.3 mg MnF ₂ into a zirconia ball mill;

(2) The high entropy oxyfluoride [MnO ₂ ] ₃ [Mg _0.25 Zn _0.25 Co _0.25 Mn _{0.25 F 2} ] 1 was obtained by ball milling to form a solid solution with _a ball-to-material ratio of 30:1, a ball milling time of 6 h, _and a rotation speed of 600 rpm/min.

Example 3

(1) Place 500 mg TiO ₂ , 32.7 mg MgF ₂ , 54.3 mg ZnF ₂ , 50.9 mg CoF ₂ , and 48.8 mg MnF ₂ into a zirconia ball mill;

(2) The high entropy oxyfluoride [TiO ₂ ] ₃ [Mg _0.25 Zn _0.25 Co _0.25 Mn _0.25 F 2 ] 1 was obtained by ball milling to form a solid solution with _a ball-to-material ratio of 30:1, a ball milling time of 6 h, _and a rotation speed of 600 rpm/min.

Result discussion: Under the premise of other consistent conditions (ball-to-material ratio 30:1, ball milling time 6h, rotation speed 600rpm/min), examples 1-3 can all prepare rutile high entropy oxyfluoride materials by adjusting the metal type of metal oxide.

Example 4

(1) 500 mg RuO ₂ , 58.6 mg MgF ₂ , 97.2 mg ZnF ₂ , 91.1 mg CoF ₂ , and 87.4 mg MnF ₂ were placed in a zirconia ball mill;

(2) The high entropy oxyfluoride [RuO ₂ ] ₁ [Mg _0.25 Zn _0.25 Co _0.25 Mn _0.25 F 2 ] 1 _was obtained by ball milling to form a solid solution with a ball-to-material ratio of 30:1, a ball milling time of 24 h, _and a rotation speed of 600 rpm/min.

Example 5

(1) 500 mg of RuO ₂ , 175.5 mg of MgF ₂ , 290.7 mg of ZnF ₂ , 272.7 mg of CoF ₂ , and 261.9 mg of MnF ₂ were placed in a zirconia ball mill;

(2) The high entropy oxyfluoride [RuO ₂ ] ₁ [Mg _0.25 Zn _0.25 Co _0.25 Mn _0.25 F 2 ] 3 was obtained by ball milling to form a solid solution with _a ball-to-material ratio of 30:1, a ball milling time of 24 h, _and a rotation speed of 600 rpm/min.

Result discussion: Under the premise that other conditions are the same, Examples 4-5 can obtain rutile high entropy oxyfluoride materials by changing the ratio of oxide to fluoride.

Example 6

(1) 500 mg RuO ₂ , 39.9 mg MgF ₂ , 128.2 mg ZnF ₂ , 91.1 mg CoF ₂ , and 87.4 mg MnF ₂ were placed in a zirconia ball mill;

(2) The high entropy oxyfluoride [RuO ₂ ] ₁ [Mg _0.2 Zn _0.4 Co _0.2 Mn _0.2 F 2 ] 1 _was obtained by ball milling to form a solid solution with a ball-to-material ratio of 30:1, a ball milling time of 6 h, _and a rotation speed of 600 rpm/min.

Example 7

(1) 500 mg RuO ₂ , 77.3 mg MgF ₂ , 66.2 mg ZnF ₂ , 91.1 mg CoF ₂ , and 87.4 mg MnF ₂ were placed in a zirconia ball mill;

(2) The high entropy oxyfluoride [RuO ₂ ] ₁ [Mg _0.4 Zn _0.2 Co _0.2 Mn _0.2 F 2 ] 1 _was obtained by ball milling to form a solid solution with a ball-to-material ratio of 30:1, a ball milling time of 6 h, _and a rotation speed of 600 rpm/min.

Example 8

(1) 500 mg RuO ₂ , 58.6 mg MgF ₂ , 97.2 mg ZnF ₂ , 91.1 mg CoF ₂ , and 87.4 mg MnF ₂ were placed in a zirconia ball mill;

(2) The high entropy oxyfluoride [RuO ₂ ] ₁ [Mg _0.25 Zn _0.25 Co 0.25 Mn _0.25 F 2 ] 1 was obtained by ball milling to form a solid solution with a ball-to-material ratio of 30: ₁ , a ball milling time of 12 h, _and a rotation speed _of 500 rpm/min.

Comparative Example 1

(1) 101.5 mg MgF ₂ , 168.5 mg ZnF ₂ , 158 mg CoF ₂ and 151.5 mg MnF ₂ were placed in a zirconia ball mill;

(2) When it is ball-milled by mechanochemical synthesis with a ball-to-material ratio of 30:1, a ball-milling time of 6 h, and a rotation speed of 600 rpm/min, no rutile high-entropy compound can be formed.

Application Example 1

The materials obtained in Example 1 and Comparative Example 1 were used as catalysts for the electrocatalytic water decomposition system to investigate their electrocatalytic water decomposition and oxygen evolution reaction performance.

Evaluation of catalytic performance: 5 mg of [RuO ₂ ] ₃ [Mg _0.25 Zn _0.25 Co _0.25 Mn _0.25 F ₂ ] ₁ prepared in Example 1 and the fluoride prepared in Comparative Example 1 were dispersed in a mixed solution of 1 mL ethanol (960 μL) and 5% Nafion (40 μL), and ultrasonicated for 30 min to form a uniform catalyst slurry; 5 μL of the mixed slurry was evenly drop-coated on the surface of a glassy carbon electrode (3 mm in diameter), and after natural drying, an electrochemical test was carried out in a three-electrode system with a carbon sheet as a counter electrode and a saturated calomel electrode as a reference electrode, using a 1 M KOH solution as the electrolyte solution, to evaluate the electrocatalytic water decomposition and oxygen evolution reaction performance of the high entropy oxyfluoride.

The above embodiments are only preferred embodiments of the present invention and are not intended to limit the implementation methods. The protection scope of the present invention shall be subject to the scope defined in the claims. Other different forms of changes or modifications may be made based on the above description. Obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (3)

1. A preparation method of a rutile type high-entropy oxyfluoride material is characterized in that the chemical composition formula of the rutile type high-entropy oxyfluoride material is [ M (IV) O ₂]_x[M(Ⅱ)F₂]_y, wherein M (IV) is any one of Ti, sn, mo, W, mn, ru, ir, pb, ge, and M (II) is at least three of Mg, mn, zn, co, fe, ni, cu; the molar percentage of each metal element to all metal elements is 5% -35%, the molar ratio of oxygen to fluorine is 1:3-3:1, and the molar ratio of any two metals in M (II) metal elements is 1:2-2:1;

The preparation method comprises the following steps:

(1) According to the chemical composition of the rutile type high-entropy oxygen fluoride material, respectively adding the rutile type single-phase metal oxide and the fluoride into a ball milling tank;

(2) And mixing the rutile type single-phase metal oxide and fluoride, and performing ball milling at the rotating speed of 500-600 rpm for 6-24 hours.

2. The method according to claim 1, wherein in the step (2), the ball-to-material ratio is 5:1 to 60:1.

3. Use of a rutile high entropy oxyfluoride material produced by the production process of any one of claims 1-2 in electrocatalytic decomposition of water.