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, NiSe 2 , CoSe 2 , and CoNiSe 2 , synthesized by hydrothermal treatment. Cubic, orthorhombic, and hexagonal structures of NiSe 2 , CoSe 2 , and CoNiSe 2 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 NiSe 2 , CoSe 2 , and CoNiSe 2 were explored by surface morphological images. Higher OER activity of the binary CoNiSe 2 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 NiSe 2 and CoSe 2 electrodes. A low Tafel slope value of 82 mV/dec was also achieved for the same binary CoNiSe 2 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.