Ultrasensitive hydrogen peroxide electrochemical sensor based on dual-phase perovskite oxide tubular nanofiber

Abstract

The ABO₃-type perovskite oxide has variable electrocatalytic activity and physicochemical properties, which make it a promising electrochemical sensing material for hydrogen peroxide (H₂O₂). Based on electrospinning and high-temperature tube furnace calcination, using LaNiO₃-type perovskite oxide as a template, we synthesized dual-phase La_0.9Sr_0.1NiO₃ nanofiber (LaSrNiO NF) perovskite oxides containing La₂NiO₄ and La_0.9Sr_0.1NiO₃ with unique one-dimensional tubular nanofiber structure by A-site (Sr²⁺) doping. The A-site doping technique significantly improves the redox properties of the perovskite oxide itself, which provides good conditions for the electrochemical sensing of H₂O₂. In addition, the porous tubular nanofiber structures also provide excellent ion transport channels and contact sites for the H₂O₂-sensing process. LaSrNiO NFs, as H₂O₂ electrochemical sensing materials, have a wide linear response range of 1 to ∼7000 μM at a low applied potential of 0.2 V and a fast response time (t = 0.9 s), as well as good selectivity and admirable long-term stability. Furthermore, a low detection limit (LOD, S/N = 3) of 0.018 μM and excellent sensitivity of 1667.9 μA mM⁻¹ cm⁻² were obtained in voltammetry cycle tests. These results indicate that LaSrNiO NFs prepared by effective doping of Sr²⁺ are promising for the determination of H₂O₂.