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

Abstract

The preparation method of a nitrogen and vanadium co-doped titanium dioxide / bismuth tantalate Z-type heterojunction photocatalyst of the present invention includes the following steps: slowly drop tetrabutyl titanate into an isopropyl alcohol solution, stir evenly, and obtain Dispersion A; add ammonium metavanadate to absolute ethanol, stir evenly to obtain dispersion B; slowly drop the dispersion B into dispersion A, stir evenly, and then naturally cool to room temperature after heating and refluxing. The product V‑TiO is obtained 2 ;Convert the V‑TiO 2 It is calcined at high temperature under an ammonia atmosphere to obtain nano-block N / V-TiO 2 Photocatalyst; combine the above N / V‑TiO 2 The photocatalyst is dispersed in absolute ethanol, and bismuth nitrate pentahydrate is added. After the bismuth nitrate pentahydrate is completely dissolved, tantalum pentachloride is added until it is completely dissolved. Then the pH is adjusted to 9 to 11 and Bi is obtained through hydrothermal synthesis. 3 tO 7 / N / V‑TiO 2 composite materials. In the present invention, TiO is co-doped with N and V 2 with Bi 3 tO 7 The synergistic effect produced by coupling not only increases the lifetime of photogenerated electrons and holes, but also 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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