Boosting Activity and Durability of an Electrodeposited Ni(OH)₂ Catalyst Using Carbon Nanotube-Grafted Substrates for the Alkaline Oxygen Evolution Reaction

Carbon nanotubes grafted on carbon papers (CP-CNTs) are used as substrates for electrodeposition of Ni(OH)2 catalysts for the alkaline oxygen evolution reaction (OER). The OER performance measured at 0.7 V (vs Hg/HgO) in 1.0 M KOH results in a fivefold increase in the turnover frequency for Ni-CP-CNT compared to Ni-CP (0.118 vs 0.022 s–1). Moreover, Ni-CP-CNT maintains a high conductivity of 0.431 S cm–2, while that of Ni-CP is low at 0.117 S cm–2. Cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) analyses confirm the phase reversibility of Ni(OH)2/NiOOH in Ni-CP-CNT but show irreversible and unstable behavior of Ni-CP. These results demonstrate that the use of CNT-grafted carbon substrates for Ni(OH)2 helps us to overcome the drawbacks of low conductivity and poor stability and enhances catalytic performance in the alkaline OER.