Designing NiHCF‐Ti ₃ C ₂ MXene Bifunctional Nano‐Heterostructure Toward the Fabrication of Supercapacitor and Electrochemical Catechol Sensor

ABSTRACT Nickel hexacyanoferrate (NiHCF) has gained great attention as a proficient electroactive material due to its superior redox behavior and tunable characteristics. Likewise, 2D MXenes with high electrical conductivity, excellent biocompatibility, and a hydrophilic surface are employed in various electrochemical applications. Herein, we intended to design a novel nano‐heterostructure through in situ growth of NiHCF nanoparticles on the titanium carbide MXene (Ti ₃ C ₂ MXene) nanosheets using a simple hydrothermal process. Thus obtained NiHCF‐Ti ₃ C ₂ MXene nano‐heterostructure has been applied toward the electrochemical detection of catechol (CA) and also as electrode material for supercapacitor fabrication. NiHCF‐Ti ₃ C ₂ MXene‐based electrochemical sensor exhibited impressive electrocatalytic activity toward CA and revealed a broad linear range for the determination of CA from 10 µM to 1.85 mM with a detection limit of 3.21 µM, with good stability and reproducibility. Meanwhile, NiHCF‐Ti ₃ C ₂ MXene‐based supercapacitor has resulted in a specific capacitance of 545 F g ⁻¹ at a current density of 1 A g ⁻¹ , and not much decrease in capacitance after 2000 cycles at 15 A g ⁻¹ is noticed. The improved analytical characteristics and energy storage efficacy attained with the prepared heterostructure could be due to the synergistic effect between the redox‐active NiHCF NPs and the highly conductive MXenes.