Growth of nano hexagon-like flake arrays cerium carbonate created with PAH as the substrate

• Petals-like Ce2(CO3)3 were synthesized with PAH.
• PAH and Ce3+ form π-allyl complex.
• The growth crystal is inhibited on (2 4 2) and promoted on (2 0 2).
• CeO2 absorption interval changed by the move to UVA from UVB.

Petals-like Ce2(CO3)3 on Ce2(CO3)3 nano hexagon-like flake arrays have been precipitatingly fabricated using PAH substrates. By changing the way of feeding, PAH concentration and aging time, petals-like Ce2(CO3)3 was created best when adding PAH into the Ce(NO3)3 solution, joined (NH4)2CO3 solution along with mixing, PAH concentration is 0.9 g/L, aging time is 4 h. A growth mechanism was proposed to account for the growth of the petals-like Ce2(CO3)3 with PAH as the substrate. Poly allylamine hydrochloride (PAH) is as template agent which forms π-allyl complex with Ce3+ and controls the morphology of Ce2(CO3)3 particle. PAH and Ce3+ form π-allyl complex, and then induce the formation of Ce2(CO3)3 crystal nucleus. And infrared spectrum analysis verified. XRD show that after adding PAH which is adsorbed on the crystal plane, the growth of Ce2(CO3)3 crystal is inhibited on (2 4 2), the growth is promoted on (2 0 2) which is differentiated into the new (1 5 1), (2 2 2) is unchanged, Ce2(CO3)3 crystal is accumulated petals shape by hexagon-like flake. UV absorption spectra show that CeO2 as prepared precursor Ce2(CO3)3 after calcinations in air at high temperatures, the petal-like CeO2 has strong UV absorption and reflection effects, and absorption interval changed significantly by the move to UVA from UVB.

Each Ce-atom connects three Cl-atoms and three allyls in three dimensional spaces. To take the plane as a reference plane which is arrayed with three Ce-atom as equilateral triangle. The triangular each vertex is Ce-atom, the triangular center place is Cl-atom, the equilateral triangle which is mutually perpendicular with Ce-triangle surface and the inclined angle is 60° is made up with three Cl-atoms.Figure optionsDownload as PowerPoint slide