Facile Synthesis and Photocatalytic Property of Titania/Carbon Composite Hollow Microspheres with Bimodal Mesoporous Shells

Table 1

Effects of calcination time on phase structure, phase content, and average crystallite sizes of TiO₂/C composite microspheres at 450°C.

Time (h)	Material abbreviations	Carbon mass ratio in composites^a (wt.%)	Anatase		Rutile
			Crystalline Size^b (nm)	Content^c (%)	Crystalline Size^b (nm)	Content^c (%)
0.5	TiO2-0.5	32.9	11 (1.0)	86.2	36	13.2
1	TiO2-1	8.2	17 (1.27)	83.5	41	16.5
2	TiO2-2	5.0	18 (1.39)	82.5	58	17.5
4	TiO2-4	1.9	21 (1.47)	80.6	68	18.4

^aEstimated from the data of TGA-DSC measurement. ^bAverage crystalline size of TiO₂ was determined by XRD using Scherrer equation. Relative anatase crystallinity: the relative intensity of the diffraction peak from the anatase (101) plane (indicated in parentheses, reference = sample calcined at 450°C for 0.5 h). ^cDetermined by XRD method.