Decoração de nanopartículas de Pt utilizando sistema wall-jet

We developed a new method to decorate Pt/C nanoparticles (NPs)with Sb and Sn ad-atoms by using a homemade wall-jet amperometric cell attached to an electronic micropipette, as shown in Fig. 1A.Firstly, the NPs to be decoratedmust be immobilized on an electrode. Afterwards, theworking electrode must be placedat the opposite side of the micropipette, at wall-jet configuration.The micropipette must contain an aliquot of the metallic precursorwhile the amperometric cell contains electrolyte.Finally, adequate volume is injected on the working electrode surface under applied potentialto decorate the Pt/C with ad-atoms.Differently from classic electrodeposition and potentiodynamic decoration [1,2], our method usesfew amount of metallic precursorwithout waste of reactants.The system allows the control of the coverage degree (θ) by changing easy handlingparameters,such as concentration of precursors, injected volume and injection flow rate. The wall-jet decorationprocedure is less reactants consuming,fast, simpleandreproducible. Here, we producedSb-and Sn-decorated Pt/CNPs and evaluated their activityin dilutedglucose andphosphate buffered-saline solution (PBS) (Fig. 1B). These first results indicatethat low θSnare capable of massively increase in the current density but high θSndo not show significant improvement. On the other hand, the output current is enhanced while Pt surface is coverage with Sb, showing significant differences for distinct θSb.These results reveal for the first time that it is possible to use wall-jet configuration to hydrodynamically decorate Pt/C NPs with ad-atoms with enhanced electroactivity.