Effect on the Photocatalytic Activity of TiO2NTs Under Visible Light of Synergistic Effect of Ti3+ and S

Abstract

TiO2 nanotube arrays (TiO2NTs) were prepared by anodic oxidation, then soaked in thiourea solution, and finally transformed into modified anatase TiO2 structure by heat treatment. Through the test results of SEM, TEM, XRD, XPS, UV-vis diffuse reflectance spectroscopy, photo-current and so on, finding that S replaces Ti[Formula: see text] in the form of S[Formula: see text], and part of the Ti[Formula: see text] is reduced to Ti[Formula: see text]. Ladder type energy band structure, producing by the appearance of S[Formula: see text] and Ti[Formula: see text], makes the electron–hole more easily and increases the carrier transfer speed to a certain degree. The photo-current size has increased from 1.07[Formula: see text]mA/cm2 to 2.13[Formula: see text]mA/cm2. By simulating decolorization test of sample to methylthionine chloride under visible light, the degradation rate of the modified sample to methylene blue increases from 32% to 63%, and increased by 1.97 times.