Abstract: Provided is a method of making colloidal platinum nanoparticles. The method includes three consecutive steps: dissolving platinum powders by a halogen-containing oxidizing agent in HCl to obtain an inorganic platinum solution containing an inorganic platinum compound; adding a reducing agent into the same reaction vessel to form a mixture solution and heating the mixture solution to undergo a reduction reaction and produce a composition containing platinum nanoparticles, residues and a gas, and guiding the gas out of the reaction vessel, wherein the amount of the residues is less than 15% by volume of the mixture solution; and adding a medium into the same reaction vessel to disperse the platinum nanoparticles to obtain colloidal platinum nanoparticles. The method is simple, safe, time-effective, cost-effective, and has the advantage of high yield.

Abstract: Provided is a method of making an inorganic platinum compound. The method includes the steps of: Step (A): providing a platinum material and a halogen-containing oxidizing agent; and Step (B): treating the platinum material with the halogen-containing oxidizing agent in a hydrochloric acid aqueous solution to obtain the inorganic platinum compound, including chloroplatinic acid or chloroplatinate salt; wherein the halogen-containing oxidizing agent excludes chlorine gas. The method of making an inorganic platinum compound is simple, safe, time-effective, cost-effective, and environment-friendly, and has the advantage of high yield.

Abstract: Provided is a method of making an inorganic platinum compound. The method includes the steps of: Step (A): providing a platinum material and a halogen-containing oxidizing agent; and Step (B): treating the platinum material with the halogen-containing oxidizing agent in a hydrochloric acid aqueous solution to obtain the inorganic platinum compound, including chloroplatinic acid or chloroplatinate salt; wherein the halogen-containing oxidizing agent excludes chlorine gas. The method of making an inorganic platinum compound is simple, safe, time-effective, cost-effective, and environment-friendly, and has the advantage of high yield.

Abstract: Provided is a method of making colloidal platinum nanoparticles. The method includes three consecutive steps: dissolving platinum powders by a halogen-containing oxidizing agent in HCl to obtain an inorganic platinum solution containing an inorganic platinum compound; adding a reducing agent into the same reaction vessel to form a mixture solution and heating the mixture solution to undergo a reduction reaction and produce a composition containing platinum nanoparticles, residues and a gas, and guiding the gas out of the reaction vessel, wherein the amount of the residues is less than 15% by volume of the mixture solution; and adding a medium into the same reaction vessel to disperse the platinum nanoparticles to obtain colloidal platinum nanoparticles. The method is simple, safe, time-effective, cost-effective, and has the advantage of high yield.