Abstract
The photocatalyst composite coatings on alumina (Al2O3) balls had been prepared by mechanical coating technique (MCT) with titanium (Ti) powder, adding a certain content of chromium (Cr) powder and a subsequent oxidation process. The effect of oxidation conditions and adding Cr on the composite coatings of chromium-titanium dioxide (Cr-TiO2) was investigated. The results show Cr-TiO2 coatings are with mixed-phase of anatase and rutile under different oxidation conditions, and the mass fraction of the rutile phase (XR) has been obviously increased when under 973 K. The SEM images indicate that adding Cr could significantly accelerate the growth of surface structures, especially at 1073 K. The photocatalytic activity of Cr-TiO2 coatings firstly increases, then decreases, with the addition of Cr. Compared with that of two other oxidation conditions, the enhancement on photocatalytic activity by adding Cr under visible light is relatively higher, especially at 973 K for 10 h.
Highlights
TiO2 has been considered as one of the most promising photocatalysts for the potential material in environment purification, sterilization, self-cleaning surfaces, and hydrogen generation due to its high photocatalytic activity, excellent chemical stability, non-toxicity, and low cost [1,2,3]
After the operation of mechanical coating technique (MCT), the composite coatings on Al2O3 balls were oxidized at the temperatures of 1073 K for 3 h, and 973 K for 3 and 10 h, using an electric furnace in air, cooled to room temperature in the furnace [15]
No characteristic peak of chromium oxide has been found, which hints either doped Cr was incorporated in the crystalline structure of the TiO2, or the chromium oxide was highly dispersed and its size was too small to be detected
Summary
TiO2 has been considered as one of the most promising photocatalysts for the potential material in environment purification, sterilization, self-cleaning surfaces, and hydrogen generation due to its high photocatalytic activity, excellent chemical stability, non-toxicity, and low cost [1,2,3]. Cr has attracted numerous attention emerging significant characteristics as an acceptor dopant in the band gap to absorb the photons of the solar spectrum, which allows photons with some lower energy and exhibit a higher photocatalytic activity under visible light [7,8,9,10]. Synthesized the TiO2 with different content of anatase and studied the relationship between photocatalytic activity and synergistic effect of anatase and rutile [11]. He et al fabricated the TiO2 with the 3D flower-like structure containing different ratio of anatase and rutile, and found the photocatalytic activity show best, when the ratio is 80:20 [12]. The effect of oxidation conditions on crystal structure and photocatalytic activity under UV and visible light was examined and discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
