Compare The Reaction Between Hexacyanoferrate And Sodium Borohydride

The electron transfer reaction between hexacyanoferrate (III) and sodium borohydride resulted in the formation of hexacyanoferrate (II) ion and dihydrogen borate ion which was strongly catalyzed by AuNPs. The redox reaction is described as BH4- + 8 [Fe (CN)6]3- + 3H2O 8 [Fe(CN)6]4- + H2 BO3- + 8H+
The advantage of hexacyanoferrate ion for this redox study is that both oxidation states of iron (+2 and +3) are quite stable with respect to dissociation and hydrolysis and possess the same chemical composition and geometry. The redox potential corresponding to the reaction being studied, Eo (Fe2+/Fe3+) is +0.44 V versus a normal hydrogen electrode (NHE). The standard reduction potential of the borate ion is Eo = -1.24 V. Hence, there is a
The rate of reduction reaction was monitored UV-Vis spectrum of hexacyanoferrate (III). The characteristic absorption peak of hexacyanoferrate (III), located at 420 nm remained unaltered for a long time in the absence of catalyst AuNPs, indicating the inability of the strong reducing agent NaBH4 itself to reduce hexacyanoferrate (III). Interestingly, up on addiction of an aliquot of AuNPs, the intensity of the absorption peak at 420 nm continuously decreased and disappeared within 23 mins as shown in Figure 11. During the redox reaction process the SPR of (530) AuNPs remained unaffected. This could be a clear evidence that the AuNPs did not aggregate during their catalytic activity. Moreover, this could also indicate that the reactants and the NPs did not undertake any chemical reaction. The kinetics of reduction reaction of hexacyanoferrate (III) catalyzed by AuNPs was studied using various amounts of catalyst and temperatures ranges of