Authors: Gengwei Zhang, Bin Wang, Lu Li, Shengchun Yang
Published: 2019-08-30
Source: Full article
AbstractRational design and synthesis of bifunctional electrocatalysts with high efficiency and low‐cost for overall water splitting is still a challenge. A simple approach is reported to prepare a phosphorus and yttrium codoped cobalt hydroxyfluoride (YP‐Co(OH)F) nanoarray on nickel foam, which displays high‐performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction in alkaline solution. The codoping of yttrium and phosphorus into Co(OH)F leads to a tuned electronic environment and favorable electron transfer, thus resulting in superior water splitting activity. The YP‐Co(OH)F electrode only requires an overpotential of 238 mV to reach a current density of 10 mA cm−2 (η10), much smaller than RuO2 (302 mV). Moreover, it displays an overpotential of 55 mV at η10 for HER, similar to that of Pt/C. When YP‐Co(OH)F is used as both anode and cathode in a two‐electrode configuration, it only demands a cell potential of 1.54 V at η10, lower than the IrO2||Pt/C couple (1.6 V) as well as other recently reported electrocatalysts. It even maintains stable water splitting for 300 h. Such a two‐electrode device can be easily driven by a 1.5 V silicon solar cell in sunlight, proving the potential of the promising catalyst for large‐scale electrolytic water splitting.