Layered double hydroxide drived ultra-evenly Rh-doped Co2Fe-P composite for high-efficient overall water splitting

•HER and OER activities could be well improved after doping a small amount of Rh.•Rh-Co2Fe-P composite only need a cell voltage of 1.54 V to drive the overall water splitting process.•The catalytic activity could be compared with most of the reported catalysts. The HER and OER catalytic activities of the composite could be well improved after doping of a small amount of Rh element and the electrocatalytic performance could be compared with that for commercial noble metal catalysts. [Display omitted] Petal-like ultra-evenly Rh-doped Co2Fe-P composite was fabricated by a solvothermal and in-situ phosphorization strategy. Through doping a small amount of Rh within the Co2Fe-P structure, the catalytic activities of the composite for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) could be highly improved, and an excellent electrochemical bifunctional catalyst could be achieved. Under acidic reaction conditions, it only required an overpotential of 76 mV for HER to achieve a current density of 10 mA·cm−2. Meanwhile, excellent electrochemical performance could also be obtained in alkaline electrolytes. The overpotential was 48 mV for HER and 303 mV for OER at 10 mA·cm−2 in 1 M KOH, respectively. Impressively, as a bifunctional electrode, the Rh doped Co2Fe-P composite can release a current density of 10 mA·cm−2 at a low cell voltage of 1.54 V in 1 M KOH for overall water splitting, which could be compared with that using commercial noble metal catalysts.