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

Abstract

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-chloropropyltrimethoxysilane (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 × 10 -4 M and 2.5 × 10 -3 M with correlation coefficient of 0.997 and detection limit was 3 × 10 -4 M.

A Hydrogen Peroxide Sensor Based on Silver Nanoparticles Biosynthesized by Bacillus subtilis

“…[48] Figure 7A which was faster than the response time of AgNPs/ ZnONRs/FTO (30-40 s). [49] The calibration plot for H 2 O 2 determination was linear in the range from 0.05 to 120 mmol•L −1 with R 2 ＝0.9960 ( Figure 7B), which was comparable with those previously reported, such as micron-silver nichrome electrode (0.098 -5.9 mmol• L −1 ), [50] Ag/SBA-15/TEPA (0.3 -2.5 mmol•L −1 ), [51] HRP/AgNL/GCE (0.039-0.52 mmol•L −1 ), [52] AgNPTiO 2 NW/GCE (0.1-60 mmol•L −1 ). [53] The detection limit was calculated to be 8 μmol•L −1 according to a signal-to-noise ratio of 3.…”

Immobilization of Human Carbonic Anhydrase on Gold Nanoparticles Assembled onto Amine/Thiol-Functionalized Mesoporous SBA-15 for Biomimetic Sequestration of CO2

“…Unbound HAuCl 4 was removed by washing the external surface of the materials with water. Controlled reduction of HAuCl 4 was performed by dropwise addition of a NaBH 4 solution followed by continued stirring for 30 min . The reddish brown mesoporous silica particles with embedded Au nanoparticles were filtered and dried under vacuum and are designated Au/APTES/SBA-15 and Au/MPTES/SBA-15.…”

Mesoporous materials and electrochemistry

“…Interestingly, such nanosystems based on platinum 387,388 or bimetallic platinumpalladium 391 nanoparticles are likely to catalyze the direct oxidation of glucose at pH values close to neutrality, 387 the use of nonmodified OMC materials required highly alkaline media. 392 Metal NPs can also be immobilized in electronically insulating materials for electrocatalytic purposes, such as gold 393 or silver 394 NPs in amine-functionalized mesoporous silica, which were then, respectively, applied to the detection of glucose 393 or H 2 O 2 394 at low overpotentials.…”