Selective degradation of ceftriaxone sodium by surface molecularly imprinted BiOCl/Bi3NbO7 heterojunction photocatalyst

Abstract

By using the surface molecular imprinting technique, BiOCl/Bi3NbO7 was used as the substrate photocatalyst and ceftriaxone sodium (CTRX) was used as the template. A molecularly imprinted photocatalyst with specific recognition and photocatalytic synergy for CTRX was synthesized. Due to the excellent photoelectric properties and the successful formation of CTRX-imprinted cavities on the imprinted layer surface. The characterization results showed that MIP-3 has the advantages of uniform particle size and high separation efficiency of photogenerated carriers. The molecularly imprinted photocatalyst MIP-3 showed remarkable synergy and selectivity in both adsorption-photocatalysis of CTRX. Further experimental results showed that MIP-3 exhibited high selective adsorption performance for both high and low concentrations of CTRX in the 30 min static adsorption experiment. About 92 % of CTRX was degraded in the 100 min light experiment, which was a large improvement compared with BiOCl/Bi3NbO7. The selectivity of MIP-BNO was evaluated by comparing the degradation efficiency of MIP-3 on CTRX and chloramphenicol (CIP). Compared to non-imprinted photocatalyst NIP-BNO, MIP-3 has a higher selectivity coefficient of 2.58 and a faster degradation kinetic rate of 0.0169 min−1. The stability experiments showed that MIP-3 has good recoverability and stability during photocatalytic degradation. The mechanism of selective photocatalytic degradation of CTRX by MIP-3 was investigated by UV–visible spectroscopy, radical capture experiments, and electron spin tests. The possible degradation pathway of CTRX was also analyzed by LC-MS. In conclusion, this study confirms that the combination of surface molecular imprinting and photocatalyst has great potential to provide a promising solution for the treatment of low-level, highly toxic target pollutants in mixed wastewater.