“…Upon light irradiation, the N -deethylation intermediates were generated, and the mass peaks at m / z values of 415.2, 387.2, and 359.3 were identified as N , N , N ′-tri-ethylated rhodamine, N , N ′-diethylated rhodamine, and N -ethylated rhodamine molecules . The active radicals in the aqueous solution generated by WO 3 /Ag 2 CO 3 –5% attack the N -deethylation intermediates, thus producing several primary oxidation products. , When the four ethyl groups in the RhB molecule are degraded, decarboxylating and ring opening may be occurred gradually under the attacking of the active radicals in the solution, resulting in the formation of intermediates with a smaller molecular weight, and the solution becomes colorless gradually . Finally, the substances with a smaller molecular weight were decomposed into H 2 O and CO 2 . ,, Besides deethylation, hydroxylation may also be involved in the photodegradation of RhB, since two possible hydroxylated intermediates with m / z values of 475.3 and 349.2 were observed in the mass spectroscopy (Figure b and Table S1).…”