Efficient oxidation of sulfides to sulfoxides catalyzed by heterogeneous Zr-containing polyoxometalate grafted on graphene oxide.

In this study, a tri-component composite named Zr/SiW 12 /GO was meticulously prepared through an ultrasonic-assisted method. This composite incorporates zirconium nanoparticles (Lewis acid), a negatively charged Keggin type polyoxometalate, and graphene oxide, and serves as a remarkable heterogeneous catalyst. The Keggin component plays multiple roles as reducing, encapsulating, and bridging agents, resulting in a cooperative effect among the three components that significantly enhances the catalytic activity. The catalytic performance of Zr/SiW 12 /GO was thoroughly investigated in the oxidation of sulfides to sulfoxides under mild conditions, employing H 2 O 2 as the oxidant. Remarkably, this composite exhibited exceptional stability and could be effortlessly recovered and reused up to four times without any noticeable loss in its catalytic activity.