Thermal Treatment of Cerium Oxide and Its Properties: Adsorption Ability versus Degradation Efficiency

Table 1

Properties of cerium oxide prepared by annealing at various temperatures.

Annealing temperature (°C)	Specific surface area (m^2/g)	Crystallite size (nm)	Point of zero charge	pH changes^a
200	153	13	5.5	4.87→7.68
300	148	15	5.7	3.43→8.22
400	138	12	6.0	3.86→8.57
500	112	13	5.7	3.95→7.64
600	62	26	6.0	4.15→8.45
700	13	69	5.8	3.67→6.22
800	3.3	205	6.0	4.72→6.44
900	1.5	205	6.1	4.74→5.22
1000	ND	205	6.1	4.29→5.22

apH changes during the sorption of AO7 on CeO₂. Initial concentration of AO7 0.1 mmol/L; sorbent : solute ratio 10 : 1 (g/L); equilibrating time 120 min.