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