Electrocatalytic Reduction of Hydrogen Peroxide on Silver Nanoparticles Stabilized by Amine Grafted Mesoporous SBA-15

Mesoporous SBA-15 was synthesized using tetraethylorthosilicate (TEOS) as the silica source and Pluronic (P123) as the structure-directing agent. The defective Si-OH groups present in SBA-15 were successively grafted with 3-chloropropyl-trimethoxysilane (CPTMS) followed by tris-(2-aminoethyl) amine (TAEA) and/or tetraethylenepentamine (TEPA) for effective immobilization of silver nanoparticles. Grafting of TAEA and/or TEPA amine and immobilization of silver nanoparticles inside the channels of SBA-15 was verified by XRD, TEM, IR and BET techniques. The silver nanoparticles immobilized on TAEA and/or TEPA grafted SBA-15 was subjected for electrocatalytic reduction of hydrogen peroxide (H2O2). The TEPA stabilized silver nanoparticles show higher efficiency for reduction of H2O2 than that of TAEA, due to higher number of secondary amine groups present in TEPA. The amperometric analysis indicated that both the Ag/SBA-15/TAEA and Ag/SBA-15/TEPA modified electrodes required lower over-potential and hence possess high sensitivity towards the detection of H2O2. The reduction peak currents were linearly related to hydrogen peroxide concentration in the range between 3 x 10(-4) M and 2.5 x 10(-3) M with correlation coefficient of 0.997 and detection limit was 3 x 10(-4) M.