CN-122006700-A - Bismuth-doped vanadate-based environment functional material, and preparation method and application thereof

Abstract

The invention relates to the technical field of photocatalytic materials, and discloses a bismuth-doped vanadate-based environmental functional material, and a preparation method and application thereof. The material is Bi x @Mn 2 V 2 O 7 , wherein x is 1-7. Bismuth is introduced on the premise of keeping stable structure of Mn 2 V 2 O 7 main crystal phase, so that material electronic structure regulation and surface reaction active site activation are realized. The preparation method comprises the steps of taking a sacrificial template as a carrier, and introducing a manganese source, a vanadium source and a bismuth source through gas-phase ion exchange reaction at 425-550 ℃ to prepare the bismuth-doped manganese vanadate photocatalytic material. The material can simultaneously and efficiently drive hydrogen evolution reaction and oxygen evolution reaction under the condition of no sacrificial agent, the generation rate ratio of hydrogen to oxygen is close to the theoretical stoichiometric ratio of 2:1, stable photocatalytic total decomposition of water is realized, the overall photocatalytic activity can be up to 27.2 times of undoped Mn 2 V 2 O 7 , the material has unexpected technical effect, and the material is suitable for the field of solar drive clean hydrogen production.

Inventors

• WANG WEILIANG
• ZHOU ZIYU
• ZHAO ERLING
• MA YONGCHAO
• LI MENGMENG
• GAO XINGANG
• SUN GAOJIE
• DONG WENPING
• NI CHENBING
• Lan Xuefang

Assignees

• 青岛理工大学

Dates

Publication Date

20260512

Application Date

20260202

Claims (10)

1. 1. A bismuth-doped vanadate-based environmental functional material is characterized in that the material is bismuth-doped manganese vanadate Bi x @Mn 2 V 2 O 7 , wherein x is 1-7.
2. 2. The material of claim 1, wherein x is 3 to 5.
3. 3. The material according to claim 1, wherein the bismuth-doped manganese vanadate has a nano-platelet, lamellar or porous structure.
4. 4. The material of claim 1, wherein Mn-O bonds, V-O bonds, and Bi-Mn bonds interact to form a multicomponent synergetic bond structure.
5. 5. The material of claim 1, wherein the material is capable of catalyzing both hydrogen evolution and oxygen evolution without a sacrificial agent.
6. 6. A method for preparing the bismuth-doped vanadate-based environmental functional material according to claim 1, comprising the following steps: (1) A sacrificial template construction step, namely growing a metal oxide nano-sheet array on a conductive substrate by a hydrothermal method to form a sacrificial template; (2) And in the gas phase ion exchange conversion step, the sacrificial template reacts with a manganese source, a vanadium source and a bismuth source through gas phase ion exchange reaction in inert atmosphere, and bismuth doped manganese vanadate Bi x @Mn 2 V 2 O 7 is formed through in-situ conversion, wherein x is 1-7.
7. 7. The method of claim 6, wherein the temperature of the gas phase ion exchange reaction is 425-550 ℃, the time of the gas phase ion exchange reaction is 5-35 min, and x is 3-5.
8. 8. Use of the bismuth-doped vanadate-based environmental functional material according to claim 1 in photocatalytic total decomposition of water.
9. 9. The method according to claim 8, wherein the photocatalytic total-decomposition water reaction is carried out in the absence of a sacrificial agent, and the photocatalytic total-decomposition water reaction is carried out under irradiation of visible light or simulated sunlight.
10. 10. The method according to claim 8, wherein the bismuth-doped vanadate-based environmental functional material is used for simultaneously catalyzing hydrogen evolution and oxygen evolution.

Description

Bismuth-doped vanadate-based environment functional material, and preparation method and application thereof Technical Field The invention relates to the technical field of photocatalytic materials, in particular to a bismuth-doped vanadate-based environmental functional material, and a preparation method and application thereof. Background The photocatalysis total water WATER SPLITTING (OWS) technology is based on a single semiconductor light absorbing material, can generate hydrogen and oxygen simultaneously through one-step light excitation under the illumination condition, has the advantages of simple reaction process, environmental friendliness, no need of external electric energy and the like, and is considered as one of important technical approaches for realizing renewable hydrogen production. The technology is hopeful to directly convert water into clean hydrogen energy under the drive of solar energy, thereby reducing the dependence on fossil energy and having wide application prospect. At present, a part of the wide band gap semiconductor materials have been proved to be capable of realizing photocatalytic full-decomposition water reaction, and materials such as TiO 2、SrTiO3 and the like can be used for realizing photocatalytic full-decomposition water reaction in an ultraviolet or ultraviolet-visible light region. However, because of the wide band gap and limited absorption capacity to visible light, the solar energy utilization efficiency is low, the overall solar-hydrogen energy conversion efficiency (STH) is extremely low, and the industrial potential is realized only when the STH is more than or equal to 10 percent. In contrast, narrow bandgap semiconductor materials have a broader visible light absorption range, and when the semiconductor material has a bandgap of less than 2.1 eV, its theoretical STH efficiency can exceed 15%, which is considered as a potential candidate for achieving efficient photocatalytic total decomposition of water. However, the existing narrow band gap semiconductor materials capable of realizing photocatalytic full-decomposition water reaction are still limited, most reported narrow band gap systems are limited by factors such as slow Oxygen Evolution Reaction (OER) dynamics, high reaction barrier, insufficient surface effective active sites and the like in the actual reaction process, and it is difficult to simultaneously and efficiently complete Hydrogen Evolution Reaction (HER) and oxygen evolution reaction under the condition of no sacrificial agent, so that the overall photocatalytic performance is limited, and even only the semi-reaction activity of hydrogen evolution is shown. Manganese vanadate Mn 2V2O7 is an n-type narrow bandgap semiconductor, the bandgap (Eg) of which is about 1.7 eV, and the conduction band and valence band edge positions (E CB≈ –0.2 V,EVB.apprxeq.1.5V) can theoretically meet the thermodynamic requirements of HER and OER simultaneously, and have good visible light response capability. But still has the problems of insufficient valence band reaction activity, slow oxygen evolution reaction kinetics and the like, has low intrinsic oxygen evolution activity, is difficult to realize efficient and stable photocatalytic full-decomposition water reaction, and has not been reported in the prior art on the realization of efficient OWS under the condition of no sacrificial agent. Therefore, how to control the energy band structure and activate the surface reaction active site by effective means on the premise of keeping the stability of the main body structure of a system with potential thermodynamic advantages of narrow band gap semiconductor materials, especially Mn 2V2O7 and the like, so as to break through the kinetic limitation of oxygen evolution reaction and realize high-efficiency photocatalysis full decomposition of water under the condition of no sacrificial agent is still a technical problem to be solved in the field. The above information disclosed in this background of the application is only for enhancement of understanding of the background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a bismuth-doped vanadate-based environment functional material, and a preparation method and application thereof. The invention provides a bismuth-doped vanadate-based environment functional material which is bismuth-doped manganese vanadate Bi x@Mn2V2O7, wherein x is 1-7. Preferably, x is 3-5. When x is 1-7, the photocatalytic total decomposition water reaction under the condition of no sacrificial agent can be realized, and when x is 3-5, the material shows optimal synergistic activity in hydrogen evolution and oxygen evolution reactions. Preferably, the bismuth doped manganese vanadate has a nano-platelet, lamella