CoNiSe2 Nanostructures for Clean Energy Production

Comparative investigation of the electrochemical oxygen evolution reaction (OER) activity for clean energy production was performed by fabricating three different electrodes, namely, NiSe2, CoSe2, and CoNiSe2, synthesized by hydrothermal treatment. Cubic, orthorhombic, and hexagonal structures of NiSe2, CoSe2, and CoNiSe2 were confirmed by X-ray diffraction (XRD) and also by other characterization studies. Perfect nanospheres, combination of distorted nanospheres and tiny nanoparticles, and sharp-edge nanostructures of NiSe2, CoSe2, and CoNiSe2 were explored by surface morphological images. Higher OER activity of the binary CoNiSe2 electrode was achieved as 188 mA/g current density with a comparatively low overpotential of 234 mV along with higher conductivity and low charge transfer resistance when compared to its unary NiSe2 and CoSe2 electrodes. A low Tafel slope value of 82 mV/dec was also achieved for the same binary CoNiSe2 electrode in a half-cell configuration. The overall 100% retention achieved for all of the fabricated electrodes in a stability test of OER activity suggested that the excellent optimum condition was obtained during the synthesis. This could definitely be a revelation in the synthesis of novel binary combinations of affordable metal selenides for clean energy production.