Interfacial Engineering of Ti ₃ C ₂ T _x ‐Protected CsPbBr ₃ Perovskite Quantum Dots for Enhanced Charge Transport and Superior Hydrogen Evolution Catalysis

ABSTRACT Hydrogen from electrochemical water splitting is a green energy carrier, but sluggish HER kinetics necessitate cost‐effective alternatives to insufficient Pt‐based catalysts. In this respect, efficient, low‐cost HER electrocatalysts are crucial for survivable hydrogen production, with inorganic halide perovskites offering variable ionic‐electronic conductivity and processability, while MXene provide complementary benefits of high conductivity and abundant active sites. State‐of‐the‐art engineering strategies and characterization techniques of CsPbBr ₃ @Ti ₃ C ₂ T _x hierarchical structure are elucidated, emphasizing how unique crystallographic features and tuneable surface terminations of Ti ₃ C ₂ T _x synergistically augment catalytic activity of pristine CsPbBr ₃ perovskite quantum dots (PQDs). Subsequently, experimental and theoretical aspects employing CsPbBr ₃ @Ti ₃ C ₂ T _x nanohybrids as efficient HER electrocatalysts are extensively discussed. Electrochemical analysis demonstrated that CsPbBr ₃ @Ti ₃ C ₂ T _x delivered a low onset potential of −231.12 mV following Volmer‐Heyrovsky pathway with reduced Tafel slope of 48.04 mV dec ⁻¹ , indicative of accelerated HER kinetics. The hierarchical structure flaunted supercilious cycling stability compared to CsPbBr ₃ PQDs, with the intensified activity emerging from efficient charge ddeliveryat CsPbBr ₃ /Ti ₃ C ₂ T _x interface, ample sites, and low R _ct . These experimental examinations are further corroborated by theoretical calculations, disclosing laudatory Gibbs free energy and enriched total density of states. CsPbBr ₃ @Ti ₃ C ₂ T _x emerge as lucrative, high‐performance HER electrocatalysts, where Ti ₃ C ₂ T _x reinforced stability and conductivity, offering fa lexible approach for next‐generation energy conversion.