Nano-zirconia coated BaTiO₃ composite for oxygen evolution reaction

Abstract

The development of efficient and stable oxygen evolution reaction (OER) electrocatalysts is vital for advancing sustainable energy storage and conversion technologies. In this study, a perovskite-based composite consisting of BaTiO3 (BTO) and nano-ZrO2 was synthesized and systematically investigated for water splitting. Structural analysis revealed a progressive shift of X-ray diffraction peaks to lower angles with increasing crystallite size (43-79 nm). The introduction of ZrO2 enhanced the textural properties, increasing the specific surface area from 7.11 to 9.42 m(2)<middle dot>g(-1) while reducing pore volume due to partial pore filling. Surface morphology and roughness variations were evaluated using field-emission scanning electron microscopy (FESEM) combined with Gwyddion software analysis. Among the composites studied, BTO loaded with 12 wt% ZrO2 (BTO@12 %ZrO2) exhibited the most favorable electrocatalytic performance. This optimized composition delivered a maximum current density of similar to 25 mA<middle dot>cm(-2) at 2.0 V vs. the reversible hydrogen electrode (RHE), with an onset potential of 380 mV. Furthermore, it maintained a stable current density of 5 mA<middle dot>cm(-2) at 470 mV over 12 h. Electrochemical analysis confirmed the highest electrochemical surface area (ECSA, 28 cm(2)) and a Tafel slope of 187 mV<middle dot>dec(-1) for the optimized catalyst. These findings demonstrate that nano-ZrO2 loading significantly enhances the catalytic activity of BaTiO3, establishing BTO@12 %ZrO2 as a promising and cost-effective alternative to noble-metal-based OER electrocatalysts.