The development of robust and low-cost oxygen evolution reaction (OER) electrocatalysts is a challenging issue in electrochemical water-splitting technology. Tailoring the electrocatalysts through nano- and composition engineering is an effective strategy to enhance the intrinsic and extrinsic electrocatalytic activities. In this study, for the first time, sodium-nickel pyrophosphate (Na2NiP2O7) is proposed as a novel OER electrocatalyst in alkaline environment. First, the electrocatalytic performance of micron-sized Na2NiP2O7 (Na2NiP2O7-micron) is evaluated. In addition, nanoscale Na2NiP2O7 (Na2NiP2O7-nano) and Fe-substituted Na2NiP2O7-nano (Na2Ni1−xFexP2O7-nano) are synthesized to improve the electrocatalytic performance of Na2NiP2O7. Although Na2NiP2O7-micron exhibits low electrocatalytic OER activity in alkaline medium, its catalytic activity can be significantly improved through reducing the particle size and substituting Fe in the Ni sites. The synthesized Na2Ni0.75Fe0.25P2O7-nano exhibits optimal catalytic activity with an overpotential of 300 mV at a current density of 10 mA/cm2 and long-term durability with continuous O2 generation over 100 hours in alkaline medium.
Bibliographical noteFunding Information:
This work is supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science and ICT, South Korea (2016M3A7B4909318) and by a Korea University Grant.
© 2020 American Ceramic Society (ACERS)
- oxygen evolution reaction
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry