Preparation method of TiO2/ZnS two-layer composite nanotube array

Abstract

The invention relates to a preparation method of a TiO2 / ZnS two-layer composite nanotube array. TiO2 is a broad-band-gap (3.2eV) semiconductor material and is a photocatalytic material researched intensively in multiple correlated fields due to the advantages such as strong oxidization capability, no photocorrosion after illumination, high catalytic activity, wide source, no toxicity and no harm, however, TiO2 also has the defects that the quantum efficiency is low, powder particles can be agglomerated and inactivated easily and TiO2 cannot be recycled easily in a using process; therefore, TiO2 is modified for solving the problems and improving the photocatalytic efficiency. Porous anodic alumina is used as a template, and ZnS is nested in TiO2 nanotubes by a liquid-phase layer-by-layer assembling method. According to the acquired two-layer composite nanotubes, the contact area of TiO2 and ZnS is increased greatly; the charge separation rate is improved and the photocatalytic efficiency is improved due to the special valence band structure of TiO2 and ZnS; and the nanotubes are distributed in an array mode and can be recovered from sewage easily, secondary pollution can be avoided, and therefore, the nanotube array has very important application significance in the aspect of sewage treatment.

Description

Technical field: [0001] The invention relates to a method for preparing an inorganic composite nanotube array, in particular to a TiO 2 / ZnS double-layer composite nanotube array preparation method, more specifically, the AAO / TiO 2 nanotube arrays, then on AAO / TiO 2 Array based ZnS embedded in TiO prepared by hydrothermal method 2 Bilayer Composite TiO Inside Nanotubes 2 / ZnS nanotube arrays. The technology belongs to the field of preparation of nanometer materials. Background technique: [0002] In recent years, industrial wastewater, especially VOCS (Volatile Organic Compounds) produced by petrochemical industry, has an increasing impact on the environment, which has seriously affected the sustainable development of the ecological environment and has aroused widespread concern in the society. With the country's emphasis on sewage discharge standards, the sewage discharge standards are getting higher and higher, prompting enterprises to demand low-cost, high-efficienc...

AI Technical Summary

Problems solved by technology

But TiO 2 There are still the following problems in the process of use: (1) TiO 2 The forbidden band is wide, and it can only absorb short-wavelength light with a wavelength below 385nm. The energy accounts for only 4% of the solar light energy. How to use the visible light and even the infrared light energy, which accounts for more than 45% of the total light energy, is the decisive factor for photocatalytic materials. Whether it can be a prerequisite for large-scale practical application

(2)TiO 2 As a single semiconductor material, the recombination rate of photogenerated electron-hole pairs is also high, and its defects such as low quantum efficiency also limit its use to a certain extent.

(3) Traditional nano-TiO 2 The powder particles are easy to deactivate, so it is not conducive to long-term utilization, poor cycle characteristics, easy to agglomerate and reduce the active reaction surface area, poor adsorption capacity, small particles difficult to recycle and other fatal defects, its application is limited to a certain extent

For TiO 2 / ZnS composite materials, most of which exist in the shape of particles, or in the form of randomly dispersed nanotubes, and most of them are ZnS particles attached to TiO 2 The outer wall of the pipe is difficult to recycle in the sewage treatment, and it is easy to cause secondary pollution

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