Paper Title
Preparation of Nano-Gold Colloid Using Electrical Spark Discharge Method To Catalyze Carbon Monoxide

Abstract
Reducing carbon monoxide concentration in the environment to avoid poisoning is important in scientific research. This study used a gold nanocolloid (AuNC) to catalyze carbon monoxide oxidation reaction to suppress its concentration. The AuNC for this catalytic reaction was prepared using Electric Discharge Machining (EDM) based on Electrical Spark Discharge Method (ESDM). The AuNC was prepared using a high-temperature electric spark to melt electrode immersed in deionized water. The electrode was 99.9% pure gold wire. The particles stripped off the electrode surface material under the high-temperature effect were combined with deionized water to form AuNC. AuNC AU 50-50-2 was prepared when the process time parameter Ton-Toff of EDM is 50-50μs, and the peak current parameter was IP2. The Energy-dispersive X-ray spectroscopy analysis showed that this colloid comprises gold and oxygen elements. Therefore, AU 50-50-2 does not adversely affect the environment when it catalyzes carbon monoxide. In the experiment using AU 50-50-2 to catalyze carbon monoxide, the carbon monoxide concentrations before and after 10 minutes of spraying AU 50-50-2 were 245.6 ppm and 221.13 ppm, respectively. Therefore, the catalytic reaction of AU 50-50-2 can reduce the carbon monoxide concentration by 9.96%. This result shows that spraying AuNPs in the environment can effectively reduce carbon monoxide concentration. Keywords - Electrical Spark Discharge Method, Nano- Au Colloid, Electrical Discharge Machining, Carbon monoxide concentration