Technical information

1. Metallic gold is a stable material chemically. To dissolve metallic gold, several strong or toxic acids are used in common, such as aqua regia, selenic acid, cyanic acid, thio-sulfuric acid, thio-urea, and iodine, etc.
   

1. We introduce a new method for dissolving metallic gold chemically, using manganese oxide powder in an aqueous solvent. Fig. 1 shows the word of FSL etched on a surface of metallic gold. The gold dissolved in the aqueous solvent takes a chemical form of HAuCl4 that was determined by UV absorption analysis as shown in Fig. 2.
   

Fig. 1 Etched surface of metallic gold by using MnO2 powder in an aqueous solution

Fig. 2 UV absorption spectra of gold dissolved in an aqueous solvent.

Red: gold dissolved in an solvent, Black: gold standard solution (HAuCl4).