view:18679 Last Update: 2019-9-6
Hamidi, H.; Shams, E.; Yadollahi, B.; Kabiri Esfahani, F.
Fabrication of Bulk-modified Carbon Paste Electrode Containing α-PW12O403− Polyanion Supported on Modified Silica Gel: Preparation, Electrochemistry and Electrocatalysis;
PW12O403− (PW12) supported on the surface of silica gel derivatized by 3-aminopropyl(triethoxy)silane (devoted brieﬂy as SiNH3PW12) was synthesized and used as bulk modiﬁer to fabricate a renewable three-dimensional chemically modiﬁed electrode. The electrochemical behavior of the modiﬁed electrode was characterized by cyclic voltammetry. There is an ionic bonding character between PW 12 and the surface amino groups of modiﬁed silica, which greatly improves the stability of SiNH 3 PW 12 -modiﬁed carbon paste electrode due to insolubility of silica gel in water. The SiNH3PW12 bulk-modiﬁed carbon paste electrode not only maintains the electrochemical activity of PW12, but also exhibits remarkable advantages of renewability, as well as simple preparation and inexpensive material. The modiﬁed electrode offers an excellent and stable electrocatalytic response for the reduction of IO3− and hydrogen peroxide. The SiNH3PW12-CPE is successfully applied as an electrochemical detector to monitor IO3− in ﬂow injection analysis (FIA). The catalytic peak current was found to be linear with the IO3− concentration in the range 5 × 10 − 6 to 1 × 10 −3 mol L−1 . The detection limit of the proposed method was found to be 3.1 × 10 −6 mol L−1 for IO3− determination.