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 O-2 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.