Facile synthesis of cubic fluorite nano-Ce_(1-x)Zr_xO2 via hydrothermal crystallization method

摘要

Nano-Ce_(1-x)Zr_xO2 (x = 0.15, 0.25, 0.5) were synthesized via co-precipitation using NH4OH as precipitant and hydrothermal crystallization. The XRD results confirmed that the cubic fluorite nano-Ce_(1-x)Zr_xO2 can form in NH4OH solution (pH > 10) at 150 °C for 12 h, and well crystallized 20-50 nm nano-Ce_(1-x)Zr_xO2 were obtained at 200 °C for 22 h. The crystal growth of Ce_(1-x)Zr_xO2 was suppressed under higher OH~- concentration and crystallite size decreased with increasing concentration of NH4OH. Ce3d XP spectra showed that the main valence state of the cerium on Ce_(1-x)Zr_xO2 surface is +4, and substituting Ce~(4+) with Zr~(4+) has no obvious influence on Ce~(3+)/Ce~(4+) ratio.