NiPS3 quantum sheets modified nitrogen-doped mesoporous carbon with boosted bifunctional oxygen electrocatalytic performance

Abstract

Electrocatalysts for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) are highly crucial and challenging toward the energy storage and conversion technologies such as fuel cells, metal-air batteries and water electrolysis. To replace noble-metal based catalysts and boost catalytic performance of carbon-based materials, we initially develop the nickel, phosphorus, sulfur and nitrogen co-modified mesoporous carbon (NiPS3@NMC) as a bifunctional oxygen electrocatalyst. The performance for ORR (half-wave potential at 0.90 V) and OER (10 mA cm−2 at 1.48 V) surpasses those of Pt/C coupled with IrO2 catalysts and most of the non-precious metal based bifunctional electrocatalysts reported in related literature. Moreover, the electrochemical durability is also confirmed by accelerated durability tests (ADTs) and long-term chronoamperometry (CA) tests. We demonstrated that the interfacial effect between NiPS3 quantum sheets (QSs) and NMC substrates by thermal activation contributed to the enhanced oxygen electrode bifunctionality with more active sites, due to the electrons-donating from nickel, phosphorus and sulfur elements and relatively enriched pyridinic type N. Such excellent overall performance highlights the potential application of NiPS3 QSs and NMC composites as the materials on energy conversion and storage.