All chemicalreagentswereofanalyticalgrade(Sigma-
Aldrich Co.Ltd.)andusedwithnofurtherpurification.
Two typesofCeO2 nano-rodswerepreparedbythe
hydrothermalmethod.Oneisfabricatedbyfirstdissolving
cerium nitratehexahydrate(Ce(NO3)3 6H2O) andsodium
phosphate(Na3PO4) indistilledwater(40mL)under an ntensivestirringfor15min(calledtype-Isamplehere-
after).