# Synthesis of copper selenide

If I react selenium powder with copper chloride powder above the melting point of selenium (221 °C), will I end up with a chunk of copper selenide, with the chlorine given off as gas, or will I lose some or all of the Se as as selenium chloride gas?

• Sounds like a bad idea to me. Chlorine certainly won't go off without a fight. Aug 16, 2019 at 19:49
• And selenium compounds can be very foul smelling. The smell also persists for a long time.
– Ed V
Aug 16, 2019 at 20:08
• The eutectic in the Cl-Se binary system is at -52C (yeah, surprised me too). All copper-selenium phases have melting points above that of selenium, the most selenium rich are stable in contact with liquid selenium making it hard to predict what would happen. Aug 16, 2019 at 20:22

There are many ways to synthesize copper selenide. It generally has two forms $$\ce{Cu2Se}$$ and $$\ce{CuSe}$$ but actually it is a non-stoichiometric compound. They are grown as nanoparticles for various applications like making semiconductor, optoelectronic components, sensors etc.
2. Using copper(II) chloride dihydrate ($$\ce{CuCl2.2H2O}$$) and sodium selenite ($$\ce{Na2SeO3}$$) in ternary oil-in-water (o/w) emulsion system. The reducing agent, sodium borohydride ($$\ce{NaBH4}$$) used to reduce sodium selenite source at room temperature(3)