Study on Triplet-Triplet Annihilated Upconversion and the Photodegradation Application

The relationship between structure and upconversion performance of four anthracene-based acceptors, named as anthracene (An), 9,10-diphenylanthracene (DPA), 9,10-di(naphthalen-1-yl) anthracene (DNACl) and 9,10-di(naphthalen-1-yl) anthracene-2-carbonitrile (DNACN), doped with Pd(II) tetraphenylporphyrin (PdTPP) was studied. Experimental measurements associated with theoretical calculations reveal that the influences of fluorescence quantum yield, Sterm-Volmer constant and energy level on the upconverted quantum yields. The upconverted fluorescence of PdTPP/DPA and PdTPP/DNACl in oil-in-water (o/w) microemulsion was investigated by temperature tuning. The efficiency of upconverted microemulsion increases with the increasing temperature. Furthermore, the upconverted o/w microemulsion has a good shielding ability to oxygen, which is critically important for application. It has been demonstrated to apply the upconverted microemulsion in photodegradation. Under the irradiation of green-to-blue upconverted microemulsion in air, the photodegradation efficiency of Rhodamine B (RhB) catalyzed by Zn0.3Cd0.7S is up to 80%. The significance in this study suggests that the upconverted microemusion has a good stability against molecular oxygen and can drive the photodegradation for water purification and environmental remediation by sun energy in air.