Lattice strain engineering in Ni3TeO6 nanostructure for enhanced oxygen evolution reaction in alkaline medium

Abstract

Thermally induced lattice strain triggered by varying the calcination temperature of the catalyst is an effective strategy to accelerate the sluggish reaction kinetics of the oxygen evolution reaction (OER). This approach has been extensively explored in numerous studies. However, the lattice strain can also be induced by altering the calcination ramp, which similarly enhances the OER performance of electrocatalysts. Despite this, the effect of calcination ramp governed lattice strain on the OER activity of electrocatalysts has been rarely explored in existing research. Here, this study provides the first comprehensive investigation of Ni3TeO6 nanostructure as an electrocatalyst for driving the OER in an alkaline electrolyte, with a particular emphasis on the influence of calcination ramp induced lattice strain on the reaction kinetics of OER. The optimized lattice strain with a slower calcination ramp imparts a high degree of distortion to the coordination environment of the NiO6 octahedral unit of Ni3TeO6, which can strengthen the absorption of oxygen intermediates (∗OH, ∗O, and ∗OOH) at the active metal sites and reveal a remarkable correlation between oxygen vacancies and catalytic activity. The catalyst prepared with a slower ramp (1°/min, NTO1) exhibited excellent OER activity in 1M KOH solution with an overpotential of 345 mV and the smallest Tafel slope of 67.8 mV/dec at 10 mA/cm2. The irreversible accelerated OER kinetic of NTO1 during thermal cycling is revealed by the non-linear Arrhenius relation between lnj vs. 1/T, resulting from the thermally induced surface reconstruction which facilitates low-barrier electron transfer. The chronoamperometry measurement performance over 24 h and cyclic voltammetry performed for 500 cycles, with a fixed scan rate of 100 mV/s, showed no significant change in OER activity, indicating the robustness durability, and excellent stability of NTO1 under the harsh operational conditions. © 2025 Hydrogen Energy Publications LLC