3D hierarchical heterostructured LSTN@NiMn-layered double hydroxide as a bifunctional water splitting electrocatalyst for hydrogen production

Abstract

The development of bifunctional electrocatalyst with effective activity and high stability for water splitting reactions is essential for hydrogen production and fuel cell technology. Herein, a 3D hierarchical heterostructure LSTN@NiMn-layered double hydroxide (La0.4Sr0.4Ti0.9Ni0.1O3-δ @NiMn-LDH) supported on highly conductive nickel foam, is presented as a novel bifunctional electrocatalyst with outstanding performance. LSTN heterostructure synthesized by sol-gel method followed by hydrothermal reaction to grow LDH layers (LSTN@NiMn-LDH) resulted in phenomenal bifunctional activity towards both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), by exhibiting a low overpotential of 125 mV at 15 mA cm−2 (OER) and 32 mV at 10 mA cm−2 (HER). Moreover, the 3D electrode showed good long-term durability for 24 hrs. stability test at a current density of 100 µA cm−2, as well as constant LSV results after operating HER for 1000 cycles. This approach of preparing heterostructure LSTN@NiMn-LDH combines the fundamental properties of La0.4Sr0.4Ti0.9Ni0.1O3-δ (highly efficient HER catalyst) with NiMn-LDH (catalytically active for OER) by using interface engineering, resultantly opens a new way of enhancing the overall activity of water splitting reactions.