Surface engineering of reduced graphene oxide onto the nanoforest-like nickel selenide as a high performance electrocatalyst for OER and HER

Abstract

Developing a robust, effective, rapid and sustainable bifunctional electrocatalyst for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly significant to meet the requirement of the increasing energy demand. Herein, we report the successful incorporation of reduced graphene oxide (rGO) onto the hydrothermally grown nanoforest-like nickel selenide (Ni3Se2) grafted on the nickel foam (NF) via a facile dip-coating route. The fabricated Ni3Se2 shows excellent catalytic activity owing to the strong affinity of Ni3Se2 towards the NF substrate. Furthermore, the incorporation of rGO onto the Ni3Se2/NF can significantly enhance the conductivity and electrocatalytic performance of the rGO/Ni3Se2/NF electrocatalyst. The as-synthesized rGO/Ni3Se2/NF electrocatalyst exhibit a low overpotential of 292.61 mV and 251.01 mV to achieve the current density of 10 mA cm−2 (OER) and − 10 mA cm−2 (HER), respectively. The proposed rGO/Ni3Se2/NF electrocatalyst exhibit enormous active sites which in turn offers the low Tafel slope value (143.00 mV dec−1 and 134.22 mV dec−1) and enhanced electrochemical active surface area (ECSA) towards the OER and HER electrocatalytic activity in 1 M KOH solution. Furthermore, the rGO/Ni3Se2/NF electrocatalyst shows superior stability for 12 hrs with the retention rate of 99.9% and 99.8%, when operated at 10 mA cm−2 (OER) and − 10 mA cm−2 (HER), respectively. Benefitting from the synergistic action of rGO and Ni3Se2, the proposed rGO/Ni3Se2/NF electrocatalyst leads to an excellent OER and HER activity. This work offers a promising strategy for the construction of highly efficient non-precious bifunctional electrocatalyst.