Redução Eletrocatalítica de Peróxido de Hidrogênio Usando um Eletrodo Nanoestruturado de Ouro preparado por Método Dinâmico de formação de Bolhas de Hidrogênio

A facile electrodeposition method so-called "dynamic hydrogen bubble template"(DHBT) was proposed to fabricate an anoporous gold film (NPGF) electrode, whose electrocatalytic activity towards hydrogen peroxide (H2O2) reduction was studied. In recent years, porous nanostructured materials play a vital rolein electrochemistry, particularlyinthe development of various electrochemical sensors owing to its inimitable advantages such as largesurface area, roughness factor, enriched electron transportrate and high stability. These structures have been typically fabricated by using dealloying and template methods. However,the impuritiespresent in the porous film, requirement of corrosive chemicals and long time associated with such procedures limit their use. Therefore, finding simple alternative ways to fabricate NPG films with high surface area is of great interest. Lately, we have prepared an NPGF electrode via anodization followed by electrochemical reduction and such sensor wasused for dissolved oxygen measurementsat low overpotential.In this work, we electrodeposited an NPGF on a gold electrode surface in 0.5 M H2SO4 solution containing HAuCl4.3H20 (5 mmol L-1) at an applied potential of -4.0 V for 100 s. The SEM image (Fig.1A) indicates the porous nanostructures and CV responses of Au & NPGF (Fig.1B) displayed large surface area & roughness factor of the electrodeposited NPGF compared to the bare electrode. Besides, the electroreduction of H2O2was evaluated and an excellent electrocatalytic activity in terms of reducing the overpotential (approx.700 mV) towards less negative potential with enhanced current signal (Fig.1C) was observed. Thus, the developed NPG may be a simple and suitable platform for H2O2reduction at low overpotential.