The fabrication and designing of an active, stable, and cost-effective bifunctional electrocatalyst with high performance for overall water splitting are of utmost importance for renewable energy supply but remain challenging. Herein, we demonstrate the facile synthesis of bimetallic nickel-manganese alloy electrocatalysts supported on a Ti surface (1×1 cm2) by electrochemical deposition through a dynamic hydrogen bubble template technique. In this work, we report the outstanding bifunctional electrocatalytic performance of fabricated Ni-Mn alloy catalysts with Ni2+/Mn2+ molar ratio of 1:3 (denoted as Ni1Mn3/Ti) and 1:4 (denoted as Ni1Mn4/Ti) for hydrogen evolution (HER) and oxygen evolution (OER) reactions in alkaline media (1 M KOH). The Ni1Mn3/Ti electrocatalyst exhibits overpotential of 170 mV and 245 mV to reach a current density of 10 mA/cm2 and 20 mA/cm2, respectively, for HER, whereas Ni1Mn4/Ti catalyst shows excellent HER activity with lower overpotentials of 149 mV and 225 mV at the current density of 10 mA/cm2 and 20 mA/cm2, respectively. Similar results were obtained for OER. The prepared catalysts have shown lower overpotential of 356 mV and 401 mV by Ni1Mn3/Ti and 366 mV and 406 mV by Ni1Mn4/Ti to drive the current density of 10 mA/cm2 and 20 mA/cm2, respectively. Both catalysts have exhibited excellent long-term durability for 10 h in an alkaline solution highlighting their robustness and higher feasibility of fabricating a number of non-precious Mn-containing active, stable binary, and ternary efficient bifunctional electrocatalysts for overall water splitting.
EFFICIENT BIMETALLIC NICKEL-MANGANESE/TITANIUM BIFUNCTIONAL ELECTROCATALYST FOR ALKALINE WATER SPLITTING
Sukomol Barua1, Aldona Balčiūnaitė1, Jūrate Vaičiūnienė1, Loreta Tamašauskaitė-Tamašiūnaitė1, Eugenijus Norkus1
1 Department of Catalysis, Center for Physical Sciences and Technology (FTMC), Vilnius, Lithuania