Nanoarchitectonics Pt/NiCo in a carbon matrix as highly efficient electrocatalyst for hydrogen evolution reaction

Abstract

Alkaline electrocatalysts for hydrogen evolution reaction (HER) are important for applications requiring long lifetime and strong catalytic activity. We have successfully synthesized Pt/NiCo@C nanoarchitectonics by a simple solvothermal approach using a box furnace. To develop the carbon matrix on the metal surface, trimesic acid was used as a carbon source at a high temperature of 750 °C in an N2 gas atmosphere. The electrical structure of the Pt-based alloy was significantly changed by the carbon matrix, which also improved the electron transport and electrocatalytic activity. In particular, the Pt/NiCo@C alloy demonstrated excellent HER performance in a 1.0 M KOH electrolyte, with a low overpotential of 48 mV required to achieve 10 mA cm−2 current density. In addition, it showed a fast kinetic response of 130 mV dec−1 when the Tafel slope was calculated. Importantly, the Pt/NiCo@C alloy demonstrated remarkable durability, with a minimum voltage loss at 10 mA cm−2 constant current density for up to 25 h of chronopotential run. This work provides some useful guidance for the synthesis of multimetal catalysts for electrochemical energy conversion.