CoTe Tailored CoNiSe₂ Nanostructures as CoTe/CoNiSe₂ Hybrids Facilitating Bifunctional Behavior in Overall Water Splitting

Designing efficient, low cost, and stable electrocatalytic systems to promote (oxygen evolution reaction) OER and (hydrogen evolution reaction) HER kinetics in the overall water splitting reaction is a key constraint. Telluride- and selenide-based electrocatalytic systems are promising materials which facilitate H+ adsorption onto active sites during the catalytic process in transition metal-based nanostructures. Herein, we developed a CoTe/CoNiSe2 hybrid system to promote interfacial charge transfer between metallic and semimetallic sites. The hybridized CoTe/CoNiSe2 nanostructures, grown in situ on Ni-foam, comprised a higher catalytic response than their pristine counterparts. Low onset potential and high current density favors the hybridization approach for these Co- and Ni-based telluride-selenide electrocatalysts. The decreased cell voltage potential of 1.40 and 1.43 V was observed in a two-electrode-based overall water splitting cell, which favors their role as proficient catalytic materials. Overall water splitting effectiveness is markedly improved by the hybrid interface between CoTe and CoNiSe2 because of greater electron mobility and larger active surface area. This work makes a substantial contribution to the catalysis field by presenting an approach for developing extremely efficient electrocatalysts.