شهرام قاسمی میر

Herein, a novel and low-cost electrocatalyst based on AuNi bimetallic nanoparticles supported on nano X zeolite (AuNiNXZ) is prepared, and its electrocatalytic activity toward oxygen evolution reaction (OER) is studied. For this aim, nano X zeolite (NXZ) is first synthesized through a hydrothermal method using silica extracted from the agro waste stem sweep and then employed as a stabilizing matrix for AuNi bimetallic nanoparticles. The unique porous structure of NXZ is beneficial to suppress the aggregation of AuNi bimetallic nanoparticles and improve their performance in the catalytic process. Furthermore, the tendency for the promotion of OER catalytic activity is manifested by the incorporation of AuNiNXZ with multiwalled carbon nanotubes (MWCNTs). After optimization of AuNiNXZ and MWCNT contents in the carbon paste electrode (25 wt % AuNiNXZ and 25 wt % MWCNT), the catalyst with improved activity just needs a low overpotential of 210 mV at 10 mA cm−2 for OER, providing a small Tafel slope of 48 mV dec−1 and great stability during a 12 h period in a chronoamperometry test. The availability of more bimetallic active sites and good electrical conductivity of the catalyst are because of the presence of both NXZ and MWCNT, respectively, which account for its superior OER activity with excellent durability.