Accelerating the Electrocatalytic Performance of NiFe-LDH via Sn Doping toward the Water Oxidation Reaction under Alkaline Condition.

Abstract

To generate green hydrogen by water electrolysis, it is vital to develop highly efficient electrocatalysts for the oxygen evolution reaction (OER). The utilization of various 3d transition metal-based layered double hydroxides (LDHs), especially NiFe-LDH, has gained vast attention for OER under alkaline conditions. However, the lack of a proper electronic structure of the NiFe-LDH and low stability under high-pH conditions limit its large-scale application. To overcome these difficulties, in this study, we constructed an Sn-doped NiFe-LDH material using a simple wet-chemical method. The doping of Sn will synergistically increase the active surface sites of NiFe-LDH. The highly active NiFe-LDH Sn0.015(M) shows excellent OER activity by requiring an overpotential of 250 mV to drive 10 mA/cm2 current density, whereas the bare NiFe-LDH required an overpotential of 295 mV at the same current density. Also, NiFe-LDH Sn0.015(M) shows excellent long-term stability for 50 h in 1 M KOH and also exhibits a higher TOF value of 0.495 s-1, which is almost five times higher than that of bare NiFe-LDH. This study highlights Sn doping as an effective strategy for the development of low-cost, effective, stable, self-supported electrocatalysts with a high current density for improved OER and other catalytic applications in the near future.