Cobalt Molybdenum Nitride-Based Nanosheets for Seawater Splitting

• DOI: 10.1021/acsami.2c09272
• Publication Date: 2022-09-08T15:27:52Z
• Authors: Xiang Wang; Xu Han; Ruifeng Du; Congcong Xing; Xueqiang Qi; Zhifu Liang; Pablo Guardia; Jordi Arbiol; Andreu Cabot; Junshan Li
• Keywords: Cobalt nitride; Seawater splitting; Catalysts; Electrocatalysts; 7. Clean energy; 01 natural sciences; 6. Clean water; 12. Responsible consumption; 0104 chemical sciences; Molybdenum nitride; 13. Climate action; Evolution reactions; Seawater; Radiology; Electrocatalysis; Hydrogen

The development of cost-effective bifunctional catalysts for water electrolysis is both a crucial necessity and an exciting scientific challenge. Herein, a simple approach based on a metal-organic framework sacrificial template to preparing cobalt molybdenum nitride supported on nitrogen-doped carbon nanosheets is reported. The porous structure of produced composite enables fast reaction kinetics, enhanced stability, and high corrosion resistance in critical seawater conditions. The cobalt molybdenum nitride-based electrocatalyst is tested toward both oxygen evolution reaction and hydrogen evolution reaction half-reactions using the seawater electrolyte, providing excellent performances that are rationalized using density functional theory. Subsequently, the nitride composite is tested as a bifunctional catalyst for the overall splitting of KOH-treated seawater from the Mediterranean Sea. The assembled system requires overpotentials of just 1.70 V to achieve a current density of 100 mA cm-2 in 1 M KOH seawater and continuously works for over 62 h. This work demonstrates the potential of transition-metal nitrides for seawater splitting and represents a step forward toward the cost-effective implementation of this technology.