Enhanced-electrocatalytic activity of Ni1-xFex alloy supported on polyethyleneimine functionalized MoS2 nanosheets for hydrazine oxidation

A high-performance Ni1-xFex on polyethyleneimine (PEI)-functionalized molybdenum disulfide (MoS2) electrocatalyst has been synthesized by an electroplating in situ growth approach. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the successful functionalization of MoS2 with PEI. The empty orbitals of Ni2+ and Fe2+ (Ni and Fe precursors) coordinated with the donated lone pairs of nitrogen atoms in PEI-mediated MoS2 and then the Ni2+ and Fe2+ were in situ reduced at a negative potential. Transmission electron microscope images and X-ray diffraction reveal that Ni85Fe15 nanoparticles with an average size of 2.25 nm are uniformly dispersed on the PEI-MoS2 sheets. The Ni1-xFex/PEI-MoS2 catalyst exhibits unexpectedly high activity towards the hydrazine oxidation reaction, which can be attributed to highly homogeneous dispersed Ni1-xFex alloy. It also shows enhanced electrochemical stability due to the structural integrity of PEI-MoS2. Finally, the Ni85Fe15/PEI-MoS2 catalyst is proved to be very valuable for applications in hydrazine fuel cells, as compared with Ni90Fe10/PANi-MoS2 and Ni85Fe15/MoS2 catalysts.