In situ controllable synthesis of magnetite nanocrystals/CoSe2 hybrid nanobelts and their enhanced catalytic performance

Fe3O4 nanoparticles (NPs) with sizes of ca 5.3, 6.6, and 9.8 nm can be successfully loaded on the surface of CoSe2-DETA hybrid nanobelts via a facile thermal reduction process in polyol solution. The resulting multifunctional nanocomposites are superparamagnetic at room temperature. Most interestingly, the electrocatalytic activity for the O2 reduction reaction (ORR) of the constructed Fe3O4-decorated CoSe2 nanobelts yield a decent enhancement compared with original CoSe2-DETA catalysts, i.e., the onset potential and current density show 1.01 mA cm−2 and 0.05 V increase at 0.3 V, 1600 rpm, respectively. Additionally, the number of electrons transferred (n) increases from 2.1 to 3.6 after integrating with Fe3O4 nanoparticles. The work described here has provided a promising route to the design and development of new Pt-free catalysts with high-performance by introducing other cheap NPs.