A self-supporting graphene supported cobalt hydroxide for enhanced oxygen evolution catalysis

A self-supporting graphene (SSG) was fabricated to act as a highly conductive catalyst support via electrochemical intercalation for a flexible graphite sheet (FGS) in 1 M KOH solution. Then cobalt hydroxide (Co(OH)2) was deposited on the surface of SSG through a convenient microwave-polyol method. The resulting electrode (Co(OH)2/SSG-FGS) exhibited remarkable catalytic performance for oxygen evolution reaction (OER) in alkaline solution, which was closely related with the unique structural advantage of the composite electrode. The self-supporting structure of Co(OH)2/SSG-FGS possessed the current collector and provided conducting channels for Co(OH)2 particles, enabling fast electron transfer from Co(OH)2 active sites along SSG to the FGS current collector and enhancing the catalytic performance of Co(OH)2/SSG-FGS for OER. Therefore, the Co(OH)2/SSG-FGS just required an overpotential of 140 mV to achieving 10 mA cm−2 in 0.1 M KOH solution, which even surpassed the commercial RuO2 catalyst. Additionally, the excellent stability of Co(OH)2/SSG-FGS highlighted its efficiency and made it preferable as an efficient catalyst for OER. [Display omitted]