Phosphorus doped two-dimensional CoFe2O4 nanobelts decorated with Ru nanoclusters and Co–Fe hydroxide as efficient electrocatalysts toward hydrogen generation

Abstract

Developing efficient and durable hydrogen evolution reaction (HER) electrocatalysts has attracted considerable attention for large-scale hydrogen generation. In this work, phosphorus doped two-dimensional (2D) CoFe₂O₄ nanobelts decorated with Ru and CoFe hydroxide clusters on iron foam (IF) (CoFeO_xH_y–Ru/P–CoFe₂O₄/IF) are synthesized via a solvothermal method followed by phosphorization procedures. The specific nanobelt morphology favors the exposure of active sites, advantageous electron transportation and intimate contact between the electrolyte and electrocatalyst. Interestingly, abundant metal hydroxide nanosheets are in situ generated on the nanobelt after the phosphorized sample is immersed in an alkaline electrolyte. Benefiting from the above merits, the developed CoFeO_xH_y–Ru/P–CoFe₂O₄/IF presents excellent electrocatalytic performances for the HER with low overpotentials of 38.6 mV, 43.2 mV, and 30.1 mV to attain 50 mA cm⁻² and 54.4 mV, 71.5 mV, and 69.3 mV to attain 100 mA cm⁻² in 1 M KOH, 1 M KOH seawater and 1 M PBS, respectively. As for overall water splitting, a cell voltage as low as 1.49 V is necessary to attain 10 mA cm⁻² and the developed CoFeO_xH_y–Ru/P–CoFe₂O₄/IF also exhibits excellent long-term stability. This work provides a new avenue for designing efficient HER catalysts with high exposure of precious metals.