Thermogravimetric study of the sulfurization of TiO2 using CS2

Titanium dioxide is the well-known catalyst for the photodecomposition of water in UV region and its nanoparticles show better performance than its bulk materials. Furthermore, partially sulfurized TiO2 is expected to be chemically stable and have an enhanced photocatalytic activity compared with TiO2. For this purpose, the sulfurization behavior of TiO2 nanoparticles was thermogravitnetrically (TG) studied by a thermo-balance with a quartz spring using CS2. From the TG curve of TiO2 nanoparticles, first, the weight decrease appeared down to around 8 wt% and then sulfurization reaction started at around 500 degreesC at a heating rate of 1 degreesC/min, The weight increase curve showed a maximum of ca 30 wt% at around 750 degreesC and then gradually decreased to ca 12 wt%. at 1000 degreesC. This would be caused by the formation of TiS2 followed by the decomposition of TiS2 to lower sulfides, such as Ti1.08S2 and Ti3S4. From the comparison of the sulfurization of TiO2 nanoparticles with that of anatase, rutile and Ti(OH)(4), it was found that TiO2 nanoparticles showed a similar behavior to that of Ti(OH)(4).