Branched CuAu nano-alloy for N2H4 oxidation-assisted H2 production and nitrite detection in water solution.

The H2 production using N2H4 splitting (OHzS) was often constrained by the requirement for insufficient stability, distinct catalysts at the anode and cathode, and the high-cost electrocatalyst associated with confined activity. This work verified the efficacy of surfactant-free branched CuAu nano-alloy as a bifunctional electrocatalyst for H2 production. Benefiting from its favorable electronic structure and surfactant-free surface, surfactant-free CuAu nano-alloy demonstrated a reduced over-potential compared with pure Cu, pure Au, and CuAu nano-alloy prepared by surfactant. When using branched CuAu nano-alloy as both cathodic and anodic electrodes, a cell voltage of 0.768 V was required to drive a current density of 10 mA/cm2. After 2550 min of H2 generation, the amplitude of the working potential for anodic reactions was found to be less than 0.92%. The enhanced electrocatalytic activity could be also applied to H2O2 and NaNO2 sensors. The CuAu nano-alloy exhibited a 2.35-folds increase in sensitivity compared to pure Au nano-crystals in the detection of H2O2. Moreover, the detection of NaNO2 in water solution has been successfully achieved. The detection range 0–175.0 mM was much wider than that of sensors in previous works. [ABSTRACT FROM AUTHOR]