화학공학소재연구정보센터
Inorganic Chemistry, Vol.50, No.18, 8774-8781, 2011
Synthesis, Structure, Negative Thermal Expansion, and Photocatalytic Property of Mo Doped ZrV2O7
A new series of compounds identified in the phase diagram of ZrO2-V2O8-MoO3 have been synthesized via the solution combustion method. Single crystals of one of the compounds in the series, ZrV1.50Mo0.50O7.25, were grown by the melt-cool technique from the starting materials with double the MoO3 quantity. The room temperature average crystal structure of the grown crystals was solved using the single crystal X-ray diffraction technique. The crystals belong to the cubic crystal system, space group Pa (3) over bar (No. 205) with a = 8.8969 (4) angstrom, V = 704.24 (6) angstrom(3), and Z = 4. The final R-1 value of 0.0213 was achieved for 288 independent reflections during the structure refinement. The Zr4+ occupies the special position (4a) whereas V5+ and Mo6+ occupy two unique (8c) Wyckoff positions. Two fully occupied O atoms, (24d) and (4b), one partially occupied 0 atom (8c) have been identified for this molybdovanadate, which is a unique feature for these crystals. The structure is related to both ZrV2O7 and cubic ZrMo2O8. The temperature dependent single crystal studies show negative thermal expansion above 370 K. The compounds have been characterized by powder X-ray diffraction, solid-state UV-vis diffuse reflectance spectra, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The photocatalytic activity of these compounds has been investigated for the degradation of various dyes, and these compounds show specificity toward the degradation of non-azoic dyes.