Al-Zain Omar Ali, Al-Masoudi and Reem Soliyman
The magnesiothermic reaction of CoO, NiO with B2O3 and Mg yielded only Co3O4, NiO. Similarly, direct reaction of CoO, NiO with elemental boron yielded CoB2O4 and NiO respectively. The reaction of CoCl2, NiCl2 with elemental boron yielded Co2B, NiO respectively. On the other hand direct reaction of pure Co, Cu metal with elemental boron in 1:1, 1:2 and 1:3 ratios produced metal oxides except 1:3 ratio produced was CoB and Cu(BO2)2. So, Solid phase with metal oxides and chlorides ended with metal oxides except with cobalt oxide and elemental Boron where CoB2O4 was produced. Reacting pure metals and elemental boron produced nano-metal borides for Co, Ni and Cu. The liquid phase reaction of CoCl2, NiCl2 and CuCl2 with sodium borohydride, NaBH4, produced black nanocrystals and nanorods of CoB2O4, Ni4B3, CuB24 and CuO.