Improvement in Efficiency of the Electrocatalytic Reduction of Hydrogen Peroxide by Prussian Blue Produced from the [Fe(CN)₅(mpz)]^2– Complex

Abstract

Hydrogen peroxide is one of the most important molecules in chemical signaling in living organisms. Because of this, its sensing is indispensable for the diagnosis of many diseases. Among the materials used for the detection and quantification of H 2 O 2 , Prussian Blue (PB) has been highlighted due to its performance. Therefore, the search for alternatives or the improvement of PB performance is a challenge. In this context, our motivation was to evaluate how the ligand N-methylpyrazinium affects the structure and reactivity of Prussian Blue films [a]

Ligand Effects of Penta- and Hexacyanidoferrate-Derived Water Oxidation Catalysts on BiVO4 Photoanodes

“…The choice of the precursors of the coordination polymers took into consideration the donor/acceptor character of the different ligands in the PCF moiety, shown in Figure . The impact of the electronic character of the ligand on PCF structures was shown in several reports, − ,, including our recent studies on electrocatalytic ascorbic acid oxidation, and hydrogen peroxide and dioxygen reduction. , The same strategy was used to study the effect of ligands on the photocatalytic activity of the BiVO 4 /CoFe–L heterostructures for water oxidation.…”

“…The structures correspond to (a) PCF–NH 3 , (b) HCF, (c) PCF–isn, and (d) PCF–mpz. The donor/acceptor character were ranked based on the E 0 values for each complex, obtained from cyclic voltammetry studies. , …”

“…In order to synthesize methylpyrazinium PCF, we first synthesized the mpz-I ligand following Monteiro et al Pyrazine (C 4 H 4 N 2 , 2.0 g) was dissolved in methyl iodide (10 mL), and the color changed to light red. The solution was kept at room temperature and in the dark without stirring for 1 week, turning into a yellow solid.…”

“…The procedure was adapted from the literature . PCF–NH 3 (0.2 g) was dissolved in water (1 mL) and then mixed with a solution of mpz-I (1 mL) in 5 fold excess (2.5 × 10 –3 mol).…”

“…Catalytic efficiency of Prussian blue analogs can be increased by using pentacyanidoferrate (PCF, [Fe­(CN) 5 –L]) precursors with different ligands (L). − Through changing the nature of the PCF ligand, these complexes modulate the electronic density on the metal centers and add new properties to the active layer, such as the introduction of structural defects in the framework and the increase of surface area.…”