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

TiO 2 nanotube arrays (TiO 2 NTs) were prepared by anodic oxidation, then soaked in thiourea solution, and finally transformed into modified anatase TiO 2 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/cm 2 to 2.13[Formula: see text]mA/cm 2 . 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.