Low-cost semiconductors have emerged as potential electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFC). The present work describes the synthesis and characterizationof Ti_0.95M_0.05O_2-δ (M = Ni, Cu, Zn) followed by the determination of ionic conductivity using a.c. impedance technique. The formation of the solid solution was confirmed by XRD, Raman, FTIR, DR-UV–Vis, PL, BET,FE-SEM, and EDX. The obtained ionic conductivities (in S cm^-1) for TiO₂ (1.92 9 10^-5), Ti_0.95Ni_0.05O_2-δ(2.78 9 10^-5), Ti_0.95Zn_0.05O_2-δ (2.16 9 10^-5) at 973 K and for Ti_0.95Cu_0.05O_2-δ (2.39 9 10^-3) at 1023 K are comparable to commercially available YSZ operating at high temperature and doped ceria electrolytes. The ionic conductivities were found to increase linearly in the temperature range of 673–1023 K. The lower activation energy of 1.08, 1.41, and 1.17 eV was obtained for TiO₂, Ti_0.95Ni_0.05O_2-δ, and Ti_0.95Zn_0.05O_2-δ,respectively. Thus, low-cost Ni, Cu, Zn-doped TiO₂ solid solutions may be regarded as plausible electrolyte materials for SOFCs.

Structural and electrical properties of Ti_0.95M_0.05O_2−δ (M = Ni, Cu, Zn) are reported for their plausible applications as SOFC electrolytes. Lower Ea of 1.08, 1.41, and 1.17 eV are obtained for TiO₂, Ni-TiO₂ and Zn-TiO₂, samples respectively. The Cu-TiO₂ showed comparable oxide ion conductivity with other potential electrolyte materials.