A Sensitive H2O2 Electrochemical Sensor Based on Pd Nanoparticles Decorated Ti2NTx MXene

Abstract

Hydrogen peroxide (H₂O₂), a prominent reactive oxygen species in organisms, plays a vital role in regulating fundamental biological activities and actively participates in cellular metabolism and stress response. Gaining insights into the quantifying H₂O₂ within living organisms has significant implications for human health research. The 2D transition metal nitride (Ti₂NT_x MXene) exhibits a thin crystal structure and enhanced electrical conductivity. A simple electrochemical sensing method for H₂O₂ is presented by employing palladium modification on Ti₂NT_x MXene. Characterization analysis confirmed the successful etching of the Ti₂AlN MAX phase into accordion-like morphology of Ti₂NT_x MXene by Li⁺ intercalation, and Pd NPs were uniformly dispersed onto the Ti₂NT_x MXene nanosheets. Electrochemical analysis revealed that optimal electrochemical detection performance for H₂O₂ was achieved when Ti₂NT_x MXene had an optimum Pd modification amount (2 wt%) at −0.4 V, exhibiting excellent stability at low concentrations. The detection limit was determined to be 0.72 µM, with a calculated sensitivity of 0.825 µA µM⁻¹ cm⁻². This study establishes the optimal amount of Pd modification and identifies Pd-Ti₂NT_x MXene as a promising candidate for electrochemical sensing applications targeting H₂O₂.