Rare-earth europium heterojunction electrocatalyst for hydrogen evolution linking to glycerol oxidation

Abstract

Electrocatalytic water splitting is regarded as the most efficient way of producing novel hydrogen energy, but is suffering from high overpotential and sluggish kinetics of oxygen evolution reaction (OER). Some organics including glycerol have been added to ameliorate the shortcomings of OER, but the selectivity of electrocatalysts is of great importance. Herein, a rare-earth metal Eu3O4/WOx heterojunction with nonstoichiometric O is designed and prepared, the Eu3O4/WO2.72 stands out from the crowd for which shows the best electrocatalytic performances that the glycerol oxidation reaction (GOR) potential is only 1.33 V at 10 mA cm−2. In addition, Eu3O4/WO2.92 and Eu3O4/WO2.72 show low overpotentials of 141 mV and 129 mV at 10 mA cm−2 for hydrogen evolution reaction (HER) compared with the benchmark Pt/C electrocatalyst. Eu3O4/WO2.72 heterojunction shows an ultralow cell voltage of 1.17 V in 1 M KOH with 0.1 M glycerol. Our study opens up a fashion-forward way for the designation of rare-earth metal heterojunction electrocatalysts in the biodiesel glycerol oxidation linking to hydrogen evolution.