Chromium nitride thermoelectric material and preparation method thereof

A method for preparing a CrN thermoelectric material, comprising steps of:

• Step 1:
• dissolving Cr(NO3)3.9H2O and PEG10000 in deionized water and adding an obtained solution drop wise with NH3.H2O under a magnetic stirrer, wherein the solution slowly turned dark green, indicating the formation of Cr(OH)3 precursor;
• separating an obtained product from the solution by filtering and washing with alcohol and deionized water several times, and drying in a vacuum;
• Step 2:
• calcining dried powder Cr(OH)3 in a CVD tubular furnace to obtain Cr2O3 powder;
• Step 3:
• nitriding the obtained Cr2O3 powder by passing ammonia gas into the CVD tube furnace to obtain black powder CrN;
• and
• Step 4:
• padding an internal wall, a top and a bottom of graphite dies with a piece of graphite paper, and loading the obtained black powder CrN into the graphite dies;
• hot-pressing the black powder CrN in the graphite dies under a nitrogen atmosphere with a hot-pressing pressure of 50-80 MPa, and then sintering with a sintering temperature of 973-1273 K and a sintering time of 10-30 min, so as to form the CrN thermoelectric material.