NiFe alloys incorporated FeCo carbonate hydroxide towards efficient electrocatalytic overall water splitting

Highly effective bifunctional electrocatalysts composed of non-noble metals are critical for sustainable hydrogen generation via water splitting. Therein, a flower-like heterostructured electrocatalyst composited with NiFe alloys and iron‑cobalt carbonate hydroxide (NiFe/FeCoCH/NF) was successfully fabricated using a combined hydrothermal and electrodeposition strategy. Benefiting from the robust mechanical stability and synergistic interaction of FeCoCH and NiFe alloys, NiFe/FeCoCH/NF achieves a low overpotential of 244 mV at 50 mA cm −2 and a Tafel slope of just 17 mV dec −1 for oxygen evolution reaction. When used as symmetric electrodes in an AEM electrolyzer, the NiFe/FeCoCH/NF-based system delivers 1 A cm −2 at a low cell voltage of 1.94 V and maintains stable operation for over 100 h, confirming its long-term reliability and great potential for industrial application. The findings indicate that NiFe/FeCoCH/NF is a promising bifunctional electrocatalyst, offering valuable insights into the rational design of efficient, stable, and cost-effective non-noble metal-based electrolyzers.