One‐step Synthesis of AuAg Alloy Nanodots and its Electrochemical Studies towards Nitrobenzene Reduction and Sensing

Efficient, stable, and low‐cost electrocatalysts for the degradation and sensing of environment pollutants are essential components of clean environment monitoring. Here we report, one‐step synthesis and characterization of 1–3 nm diameter sized bi‐metallic AuAg nanodots (NDs) embedded in amine functionalized silicate sol‐gel matrix (SSG) and its electrochemical studies toward nitrobenzene. The SSG was used as a reducing agent as well as stabilizer for the prepared mono‐ and bi‐metallic nanoparticles (NPs). From the HRTEM, STEM‐EDS and XPS analyses, the bi‐metallic AuAg NDs were identified as an alloy and not the mixtures of Au and Ag NPs. Characteristic surface plasmon resonance (SPR) band between the Au and Ag NPs SPR absorption region was noticed for the prepared AuAg NDs. The AuAg alloy NDs with different concentrations of Au and Ag (Au₂₅Ag₇₅, Au₅₀Ag₅₀ and Au₇₅Ag₂₅ NDs) modified electrodes exhibited synergistic electrocatalytic effect than did the Au and Ag NPs towards nitrobenzene reduction and detection. Together with ultra‐small size and exceptional colloidal stability features within these SSG‐AuAg NDs pave convenient way for nanotechnology‐based catalysts development and sensor applications.