An efficient CoOx-SnOx(Sb doped)/Ti electrocatalyst for the oxygen evolution reaction

Abstract The oxygen evolution reaction is considered the heart of water splitting technologies. Herein, we reported two CoOx-SnOx (Sb doped)/Ti (CSTE-480 and CSTE-600) as high conductive, active, stable and noble metal-free electrocatalysts for oxygen evolution reaction under alkaline condition. The CSTEs electrocatalyst containing conductive Ti-O-Sn(Sb)-O-Co chain were designed and synthesized via a simple layer-by-layer method. XRD, SEM, and FT-IR discovered that the two prepared CSTE electrodes had both amorphous cobalt oxides and octahedral Co3O4 spinel. Under the same conditions, the OER activities and stabilities of CSTEs were superior to commercial Pt and IrO2/Ti respectively. The overpotential and Tafel slope of CSTE-600 for OER at 10 mA·cm−2 was only 317 mV and 40 mV/dec respectively, indicating that it was a highly active OER catalyst. The compared analysis of SEM, Co valence state, and XRD before and after reaction revealed that CSTE-600 was very stable. Moreover, The OER activity of CSTEs was affected by morphology, the redox of cobalt ion, SnTiO3, and Co2SnO4 on the surface. This strategy can be extended to synthesize other OER electrocatalysts.