Magnetic propulsion of recyclable catalytic nano-cleaners for pollutant degradation

Abstract

Electrochemically fabricated magnetic mesoporous CoNi@Pt nanorods are excellent nanomotors with controlled magnetic propulsion and excellent catalytic properties. The core–shell structure allows a double functionality: (i) controlled motion of the nanorods by applying rotating magnetic fields at different frequencies and field strengths and (ii) effective catalytic activity of the platinum shell for reactions involving sodium borohydride. The structure and magnetic properties of the CoNi core are not modified by the presence of the Pt shell. Nanorods were propelled via a tumbling-like dynamic by a rotating magnetic field. While in absence of NaBH4, nanorods move at constant speed showing a linear path; in the presence of NaBH4, they showed an intermittent trajectory. These catalytic nanorods can be used as nanocleaners with controlled directionality for pollutants degradation in the presence of borohydride. Their magnetic character allows control of the velocity and the direction throughout the contaminated solution by degrading the different pollutants in their path. The magnetic character of nanorods also allows their easy recycling.