Characterization of Various TiO2 Powders Used for Complete Decomposition of Organic Wastes by Means of Thermally Excited Holes at High Temperatures

Abstract

Disposal of organic wastes is a social problem of high importance. We previously reported on a decomposition system of organic wastes by the use of thermally excited holes in TiO2 at high temperatures. An appealing feature of our system is that it makes use of a great number of holes formed at, for example, 350°C. In the present investigation, characterization has been carried out on various TiO2 powders that have nearly the same composition but differ in specific surface and particle size in an attempt to screen and select the most powerful powder. The decomposition ability of TiO2 has been evaluated using previously investigated polycarbonate (PC)-coated TiO2 as the model system, with special attention to the interaction between the adsorbate (PC) and the adsorbent (TiO2). As a result, the specific surface was found to play the most important role, and is closely linked to the adsorption amount of PC on TiO2, released energy, spin concentration, deep coloration, as well as to the Raman peak-shift. In addition, the crystallinity is also found to be effective in connection with the lifetime of holes.