Ultra-trace Ru-doping FeNiCo-NC bifunctional electrocatalyst for efficient overall water splitting

In this letter, NiCo/NC, FeNiCo/NC, RuFeNiCo-NC were designed and synthetized using a two-step strategy. For FeNiCo/NC and RuFeNiCo-NC, transition metal alloy nanoparticles, such as Fe3Ni2 and Co3Fe7, are embedded in porous carbon matrix with multi-layered structures. The addition of ruthenium trichloride caused a change in the relative content of Fe3Ni2 and Co3Fe7 of the sample. As a bifunctional electrocatalyst, the RuFeNiCo-NC-3 only requires overpotential of 330 mV and 60.7 mV to achieve 10 mA cm- 2 for OER and HER, respectively. During overall water splitting, the assembled RuFeNiCo-NC-3//RuFeNiCo-NC-3 cell only needs voltage of 1.57 V to achieve current density of 10 mA cm- 2. This provides a simple approach to prepare low-cost electrocatalyst for excellent overall water splitting.