Engineering Ti- MXene / LaNiO₃ Perovskite Composites for Efficient HER and OER Electrocatalytic Performance

Abstract

The demand for renewable energy has driven interest in water splitting, where HER and OER require efficient electrocatalysts due to sluggish kinetics. Although LaNiO₃ perovskite offers good redox activity and stability, its poor conductivity and low surface area limit performance. To address this, a Ti₃C₂Tₓ MXene -supported LaNiO₃ composite was developed. MXene was synthesized via HF etching and LaNiO₃ via coprecipitation, followed by ultrasonication and stirring to form the composite. FESEM confirmed nano cube LaNiO₃ uniformly distributed on layered MXene, while XPS verified oxidation states and surface terminations (F, O). Electrochemical studies (CV, LSV, and EIS) conducted in 1 M KOH using a Ni foam electrode demonstrated excellent bifunctional performance of the Ti₃C₂Tₓ @LaNiO₃ composite. It exhibited low overpotentials of 90 mV for HER and 350 mV for OER at a current density of 10 mA cm⁻², along with Tafel slopes of 59 mV dec⁻¹ (HER) and 100 mV dec⁻¹ (OER), indicating favorable kinetics. The composite also showed higher Cdl (larger ECSA) and lower charge transfer resistance (Rct) compared to pristine LaNiO₃. Stability tests confirmed its strong durability under alkaline conditions.