Facile synthesis of polyaniline/titanium carbide (MXene) nanosheets/ palladium nanocomposite for efficient electrocatalytic oxidation of methanol for fuel cell application

摘要

Slow methanol oxidation reaction kinetics with current electrocatalysts is the major limitation to widespread application and development in direct-methanol fuel cells (DMFCs). The present work demonstrates a highly efficient electrocatalyst for methanol electrooxidation reaction (MEOR) using polyaniline/palladium/Ti3C2Tx (PANI/Pd/MXene) nanocomposite. The PANI/Pd/MXene nanocomposite was prepared using a one-pot electrochemical co-deposition technique with a pre-anodized screen-printed electrode (SPE) under acidic electrolyte solution containing Ti3C2Tx, aniline, and palladium chloride as precursors. The PANI/Pd/MXene nanocomposite was examined using FESEM, TEM, FT-IR, XPS, and cyclic voltammetric techniques. The electrochemical response of the PANI/Pd/MXene nanocomposite shows enhanced electrocatalytic response towards the oxidation of methanol, with a peak current density of 291 mA cm-2, approximately three times higher than Pd/MXene (106 mA cm-2). Furthermore, it was also stable up to 100 cycles. The electrochemically active PANI/Pd sites are incorporated with MXene nanosheets, facilitating a more efficient MEOR. This stimulating result was achieved due to the sturdy metal-support interactions between PANI/Pd and MXene nanosheets that provide maximum methanol adsorption on the electrode surface for efficient electrocatalytic oxidation. Thus, the Ti3C2Tx support tailors the metal electrocatalyst interface and surface properties, resulting in improved electrocatalytic performance. This study highlights a facile approach for designing MXene-supported noble metal electrocatalysts for MEOR in direct-methanol fuel cells.