Preparation method and application of a nitrogen and vanadium co-doped titanium dioxide/bismuth tantalate z-type heterojunction photocatalyst

Abstract

The invention relates to a preparation method of nitrogen and vanadium co-doped titanium dioxide / bismuth tantalate Z-type heterojunction photocatalyst. The method comprises the following steps of: slowly dropping tetrabutyl titanate into an isopropanol solution, stirring uniformly the materials to obtain dispersion liquid A; adding ammonium metavanadate to anhydrous ethanol, and uniformly stirringthe materials to obtain dispersion liquid B; slowly dropping the dispersion liquid B into the dispersion liquid A, uniformly stirring the materials and performing heating backflow processing, and then naturally cooling the material to room temperature to obtain a product V-TiO2; and placing the V-TiO2 at ammonia atmosphere and performing high-temperature calcining to obtain a nano-block N / V-TiO2photocatalyst; dispersing the above N / V-TiO2 photocatalyst in absolute ethanol, adding bismuth nitrate pentahydrate, after bismuth nitrate pentahydrate is completely dissolved, adding tantalum pentachloride to completely dissolve the material, adjusting a pH to 9-11, and performing hydrothermal synthesis to obtain the Bi3TaO7 / N / V-TiO2 composite material. In the present invention, the synergistic effect produced by the coupling of N, V co-doped TiO2 and Bi3TaO7 increases the lifetime of photogenerated electrons and holes, and effectively improves the stability of the composite catalyst.

Description

technical field [0001] The invention belongs to the technical field of nanomaterial synthesis, and in particular relates to a preparation method and application of nitrogen and vanadium co-doped titanium dioxide / bismuth tantalate Z-type heterojunction photocatalyst. Background technique [0002] Titanium dioxide (TiO2) is widely used in energy conversion, wastewater treatment, environmental purification, sensors, coatings, cosmetics, catalysts, Many fields such as fillers have attracted great attention from scholars at home and abroad. Especially as an N-type semiconductor material with excellent performance, it can make full use of solar energy, which is energy-saving and environmentally friendly. It is a nano-functional material with the broadest application prospects. Although titanium dioxide is a potential photocatalyst, the wide band gap (anatase is about 3.2eV and rutile is about 3.0eV) makes TiO2 only able to be absorbed by short-wavelength ultraviolet rays (λ﹤387nm...

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Problems solved by technology

[0004] The main principle of non-metal element doping is to replace nano-TiO with non-metal elements 2 O in 2- Or fill non-metallic elements into the TiO2 lattice gap to change the chemical composition and structure of TiO2, and then change its optical properties. Currently, the commonly used preparation methods mainly include: solution combustion method, hydrothermal method, sol-microwave hydrothermal method Combined with ultrasonic technology, etc., the C and N-doped nano-titanium dioxide prepared by the solution combustion method is mainly anatase type, the grain size is 9-15nm, and the particle size distribution is 30-180nm, but the process time of this method is longer , and the production cost is high, the formed material is easy to agglomerate, and the utilization efficiency is low, which is not conducive to the promotion and use in practical applications; N-doped TiO2 microspheres prepared by sol-microwave hydrothermal method combined with ultrasonic technology are not destroyed before and after hydrothermal reaction The morphology of the microspheres, but the surface has obvious nanocrystal assembly phenomenon, and with the increase of the amount of ammonia water, the close accumulation and agglomeration of nanocrystal grains appear on the surface of some samples, which seriously affects the photocatalytic efficiency.

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