Coaxial heterojunction TiO2 nanotube array and preparation method thereof

Abstract

The invention provides a nanotube with a coaxial heterojunction structure of an ordered array and a preparation method for a nanotube array film with the coaxial heterojunction structure. A surface is formed by an under potential sedimentation process to chemically limit growth and the epitaxial growth is realized from the angle of a monoatomic layer. An epitaxial sensibilization heterogeneous phase is uniformly covered on the tube wall of the TiO2 nanotube to form the coaxial heterojunction structure together with the nanotube array so as to avoid the phenomenon that an epitaxial sensibilization layer blocks the nanotube. The coaxial heterojunction structure cannot reduce specific surface area and adsorbability of the TiO2 nanotube array, is beneficial to improve the contact area of a sensitizing agent and the TiO2 surface and can effectively improve the visible light response performance of the TiO2 nanotube ordered array. The photoelectric conversion efficiency of the CdS / TiO2 coaxial heterojunction nanotube array prepared by the method reaches 8.13 percent under the full spectrum simulated sun illumination. The CdS / TiO2 coaxial heterojunction nanotube array can be widely applied to the fields of photochemical catalysis, solar cell, gas sensing, biomedicine and the like.

Description

technical field [0001] The invention relates to a one-dimensional nanotube array, in particular to a coaxial heterojunction nanotube in an ordered array, and a preparation method for the nanotube array film with the coaxial heterojunction structure. Background technique [0002] TiO 2 Nanotube arrays have good photocatalytic activity and photoelectric conversion efficiency. TiO 2 Belonging to wide bandgap semiconductors, its maximum absorption wavelength is in the ultraviolet region, especially, the highly active nano-TiO developed in recent years 2 For photocatalysts, the light absorption band is further blue-shifted due to the quantum size effect. Since ultraviolet light accounts for less than 5% of the total energy of sunlight, research on how to make TiO 2 It is of great significance to extend the photocatalytic activity to the visible light region, so as to efficiently use sunlight to excite photogenerated carriers. For this reason, many researchers through the TiO...

AI Technical Summary

Problems solved by technology

However, the optoelectronic performance of these composite heterojunctions needs to be further improved.

The main reason is that TiO 2 Due to the special surface structure of nanotube arrays, heterogeneous phases generated by conventional methods are easily deposited on TiO 2 Inside the nanotubes, even clogging the nanotubes, resulting in a decrease in the specific surface area and adsorption capacity

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