We first report a facile hydrothermal method to synthesize Ca doped 3R-CuFeO2 nanoplates with 100-400 x 15-40 nm(2) at 100 degrees C for 24 h. The Ca dopants have a significant effect on the crystal structure of CuFeO2, as our investigation shows clearly that the Ca2+ ions were successfully doped into the CuFeO2 lattice and substituted Cu+ ion, resulting in the formation of Cui(1-2x)Ca(x)FeO(2) solid solution of a rhombohedral 3 R structure. Furthermore, the calculated direct bandgap energies of (Ca doped) CuFeO2 nanoplates were estimated to be 3.20-3.40 eV, and the optical bandgaps decreased with increasing concentration of Ca dopant. The mott-schottky anaylsis results indicated that (Ca doped) CuFeO2 nanoplates have a p-type semiconductor behavior, and the carrier density of these CuFeO2 based nanoplates around 10(20) cm(-3), which also decreased with increasing concentration of Ca dopant due to the Ca2+ ion replacement of a part of Cu+ ions. (C) 2016 Elsevier Ltd. All rights reserved.