TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The gallium particles colloid preparing step comprises adding solid gallium metal into a first solvent, heating the first solvent to melting point of gallium metal, and performing secondary ultrasonic treatment. The secondary ultrasonic treatment is performed for 1-6 hours. The copper precursor solution is prepared by dissolving copper precursor in a second solvent. The copper-gallium binary nanoparticles forming step comprises preparing a mixed solution of gallium particles colloid, copper precursor solution and reducing agent, heating the mixed solution to 150 degrees C, and performing primary ultrasonic treatment for 1-6 hours. The first precursor solution is obtained by dissolving copper precursor and indium precursor in the first solvent. The dispersion solution preparing step comprises preparing gallium particles colloid, preparing a second precursor solution containing copper ions, mixing gallium particles colloid, the second precursor solution and reducing agent, and ultrasonically treating to form copper-gallium binary nanoparticles. The copper-indium-gallium ternary nanoparticles forming step comprises preparing mixed solution of the first precursor solution, dispersion solution and reducing agent, heating the mixed solution to 150 degrees C, and performing ultrasonic treatment for 1-6 hours. Preferred Components: The copper precursor includes at least one of copper(I) acetate, copper(II) acetate, copper(II) fluoride, copper(I) chloride, copper(II) chloride, copper(I) bromide, copper(II) bromide, copper(I) iodide, copper(II) perchlorate, copper(II) nitrate, copper(II) sulfate and their hydrates. The copper-gallium binary nanoparticles have core shell structure with a gallium core and copper shell. The indium precursor includes indium acetate, indium(III) chloride, indium(III) nitrate, indium(III) sulfate, indium(III) hydroxide and their hydrates.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The first solvent and the second solvent include at least one of ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, hexylene glycol and butylene glycol. EXAMPLE - Copper precursor solution (prepared by mixing copper sulfate and mixed solution of glycol and tetraethylene glycol), gallium particles colloid (prepared by mixing gallium metal and tetraethylene glycol, and ultrasonically treating) and sodium borohydride were sonicated for 3 hours, centrifuged, washed, and dried for 8 hours to obtain copper-gallium binary nanoparticles.