Highly Selective Deethylation of Rhodamine B on TiO_(2) Prepared in Supercritical Fluids

摘要

Pure phase anatase TiO_(2) nanoparticles with sizes of 5-8 nm and varying crystallinity were synthesized in supercritical isopropanol/water using a continuous flow reactor. Their photodegradation of rhodamine B (RhB) was evaluated under visible light irradiation. The as-prepared TiO_(2) nanoparticles show much higher photodegradation efficiencies than commercial Degussa P25 TiO_(2). Moreover, the photodegradation of RhB on the as-prepared TiO_(2) follows a different process from that on P25 TiO_(2), quicker N-deethylation and slower cleavage of conjugated chromophore structure. Based on PXRD, TEM, and BET measurements, these two photodegradation properties have been explained by the physicochemical properties of TiO_(2).