Photothermally Active Core–Shell Catalyst Based on UiO-66 and Polydopamine for Highly Effective Detoxification of Nerve Agents

Abstract

A new, photothermally active, catalytic composite (Fe 3 O 4 @PD@UiO-66) based on UiO-66 and polydopamine (PD) was prepared for the decomposition of chemical warfare agents (CWAs). An iron oxide nanoparticle was introduced to enable rapid recovery after the reaction. The PD layer enabled conversion of the absorbed light into heat under infrared (IR) irradiation and increased the reaction temperature, thereby increasing the reaction rate. Dendrimer-functionalized silica particles (NH 2 -DS) were used as heterogeneous catalyst regenerators instead of N-ethylmorpholine. Under IR irradiation, a mixture of Fe 3 O 4 @PD@UiO-66 and NH 2 -DS was effective as a heterogeneous catalyst for degrading DMNP, with a 5 min half-life in water. Without IR irradiation, the half-life of DMNP was 45 min using the same catalyst mixture. Various bases including arginine, histidine, and D4 were directly modified on the surface of Fe 3 O 4 @PD@UiO-66 and used without NH 2 -DS or N-ethylmorpholine in order to compare their reactivities. Furthermore, a mixture of Fe 3 O 4 @PD@UiO-66 and NH 2 -DS was used for the decomposition of nerve agents, including sarin (GB), soman (GD), and VX, under IR-LED irradiation. Remarkably, GB was effectively decomposed with a half-life of 4.2 min, and GD demonstrated a half-life of 8.7 min. VX was hydrolyzed with a half-life of 14.0 min.