A new multi-cobalt substituted molybdovanadate [{Co (H2O)5}4{Co8(OH)2(H2O)2V10Mo30O132}]12-: Synthesis, crystal structure and surface photovoltage

A novel multi-cobalt substituted molybdovanadate, (NH4)12[{Co(H2O)5}4{Co8(OH)2(H2O)2V10Mo30O132}]. 68H2O (1), was isolated via in situ self-assembly reaction of NaVO3.2H2O, (NH4)6Mo7O24.4H2O, and CoCl2.6H2O in the aqueous solution. Structural analysis reveals that compound 1 displays a zero-dimensional (0D) framework constructed from the Z-shaped {V10Mo30Co8} cluster surrounded by four {Co(H2O)5} units. The morphology of compound 1 features a lamellar construct, smooth surface, and regular edges with sizes 50-150 mu m. Photophysical measurements indicate that compound 1 shows solid-state semiconductor-like characteristics of both the surface photovoltage response and the optical band gap of ca. 2.04 eV.