preparation and study of bismuth oxide doped and co-doped with cobalt(iii) and holmium(iii) via sol-gel method

in this research work the solid-solutions of (bi2o3)1-x (co2o3)x, [x= 0.05, 0.1] (1), (bi2o3)1-x (ho2o3) x, [x= 0.025, 0.05] (2), and (bi2o3)1-x-y (co2o3)x (ho2o3)y, [x=0.05] ; [y= 0.01, 0.02] (3) have been synthesized  using sol-gel method. the effects of transition metal oxides doping on the crystallization and phase transition of the bi2o3 were discussed by x-ray diffraction (xrd). the xrd pattern showed that 1 and 3, have body center cubic (bcc) single phase; similar to γ- bi2o3. while 2, has phase transition from bcc to tetragonal phase. the surface morphology of the samples was assessed by scanning electron microscopy (sem). furthermore electrochemical properties of electrodes modifying by these new synthesized ceramics were studied by cyclic voltammetry (cv).