The invention relates to the technical field of
precious metal compound synthesis, in particular to high-purity
rhodium triiodide and a preparation method thereof.The preparation method comprises the following steps that
solid rhodium trichloride is put into a reaction kettle, the temperature is increased,
ozone is introduced, when reaction
tail gas is absorbed by
silver nitrate and no white precipitate is generated, reaction continues for 1-1.5 h, and
rhodium oxide powder is obtained; washing the rhodium
oxide powder until no white precipitate exists after the washing solution is mixed with the
silver nitrate solution, adding hydriodic acid and an initiator into rhodium
oxide, heating and refluxing, and reacting for 4-6 hours to obtain black
crystal powder; and washing and
drying the black
crystal powder to obtain the high-purity rhodium
triiodide. According to the method, the
chlorine element in the
solid rhodium trichloride is oxidized into
chlorine gas through
ozone, so that the
chlorine element in the
raw material is removed, and the problem that chlorine ions in the final product exceed the standard is avoided. A hydriodic acid solution is adopted to react with rhodium oxide, no
metal impurities or other substances are introduced in the reaction process, and the content of
chloride ions in the high-purity rhodium
triiodide prepared by the method is 1-5 ppm.