Efficient degradation of antibiotics by Bi0–Bi4Ti3O12/Ag2CO3 with the surface plasmon resonance effect under visible light irradiation

A novel Bi 0 –Bi 4 Ti 3 O 12 /Ag 2 CO 3 composite photocatalyst with Z-type heterojunction was successfully synthesized. The best degradation rate of Bi 0 –Bi 4 Ti 3 O 12 /Ag 2 CO 3 for tetracycline hydrochloride (TC) can reach 89.03% under the optimized reaction conditions and its reaction rate constant was 0.01517 min −1 , 2.89 times that of pure Bi 4 Ti 3 O 12 . In addition, the catalyst showed a good universality to the other three antibiotics. The results of catalyst characterization showed that the enhanced photocatalytic activity of Bi 0 –Bi 4 Ti 3 O 12 /Ag 2 CO 3 was mainly due to the surface plasmon resonance (SPR) effect of reduction of Bi 3+ and the formation of heterojunction between Bi 0 –Bi 4 Ti 3 O 12 and Ag 2 CO 3 . Active species capture experiments and electron paramagnetic resonance (EPR) results showed that •O 2 ‾ and h + played a major role in the reaction process. The degradation pathway of TC by Bi 0 –Bi 4 Ti 3 O 12 /Ag 2 CO 3 was analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS). Moreover, a possible electron transfer mechanism of Z-type heterojunction was deduced.