Enhanced catalytic performance of M-doped SnS2 (M: Ni, Cu, Fe, and Co) and graphene nanocomposite for oxygen reduction reaction in alkaline media

In this study, the electrocatalytic behavior of tin sulfide doped with various metallic elements (copper, cobalt, nickel, and iron) for the oxygen reduction reaction was investigated. Our findings reveal cobalt as the most effective dopant in enhancing ORR efficiency. The graphene nanosheets were introduced to form a G/Co-SnS2 nanocomposite, which significantly improved ORR performance, surpassing Pt/C in current density. Our findings underscore the positive impact of chemical doping and the synergistic effect of SnS2 with graphene nanosheets, improving the onset potential and facilitating the ORR. Through comprehensive characterization including XRD, XPS, FESEM, and BET analysis, the structural and surface properties of the materials were evaluated. Employing the Rotating Disk Electrode technique, we observed that G/Co-SnS2 exhibited a superior onset potential of 0.88 V vs. RHE and high current density of 6.12 mA cm-2, indicating enhanced ORR facilitation. Furthermore, Electrochemical Impedance Spectroscopy revealed lower resistance in the G/Co-SnS2 nanocomposite compared to other samples, highlighting its enhanced durability. Additionally, G/Co-SnS2 nanocomposite demonstrated significantly enhanced durability in comparison to the costly Pt/C catalyst, further underscoring its potential as a robust alternative for catalyzing the oxygen reduction reaction. These comprehensive characterizations provide insights into the enhanced electrocatalytic performance observed. Overall, this study highlights the promising potential of Co -doped SnS 2 in combination with graphene nanosheets for efficient oxygen reduction reactions, opening avenues for advanced electrocatalytic materials in energy applications.