Studies on the photodegradation of Rhodamine dyes on nanometer-sized zinc oxide.

The nanometer-sized ZnO was prepared through the sol-gel method. Its average particle diameter, determined by TEM, was 20-30 nm. The specific surface area was determined to be 22 m2 g(-1) by BET. The photodegradation mechanism of Rhodamine dyes on nanometer-sized ZnO was studied by dynamic molecular spectra, and the results showed that the photodegradation of Rhodamine dyes obeyed the rules of a pseudo first-order kinetic reaction. The rate constant k of the degradation of Rhodamine B (RB) and butyl-Rhodamine (BR) were 0.0128 and 0.0154 min(-1), respectively, and the half period t(1/2) were 60 and 52 min, respectively. The photodegradation reaction conditions were optimized. After intermixing with silver, the photodegradation efficiency was greatly improved. A life-span test showed that nanometer-sized ZnO had a long life-span.