Enhanced Photocatalytic Activity of TiO₂ Powders (P25) via Calcination Treatment

Table 1

Effect of temperature on physicochemical properties of TiO₂ samples.

Temperature; (°C)	^aPhase content; (%)	^bCrystalline size; (nm)	^cSBET; (m^2/g)	^dPore volume; (cm^3/g)	Average pore size; (nm)	^ePorosity; (%)
P25	A: 72.7; R: 27.3	29.5	45.7	0.177	7.57	41.5
400	A: 72.7; R: 27.3	31.7	25.9	0.0929	8.24	27.1
500	A: 66.4; R: 33.6	33.8	22.7	0.0597	10.7	19.4
600	A: 55.2; R: 44.8	48.6	18.7	0.0503	10.5	17.0
700	A: 9.8; R: 90.2	63.2	8.59	0.0177	14.4	7.00
800	R: 100	99.0	4.39	0.00831	15.5	3.45

Calcination time: 4 h
^aA and R denote anatase and rutile, respectively. ^bAverage crystalline size of TiO₂ was determined by XRD using Scherrer equation. ^cThe BET surface area was determined by multipoint BET method using the adsorption data in 𝑃/𝑃₀ range from 0.05 to 0.3. ^dPore volume and average pore size were determined by nitrogen adsorption volume at 𝑃/𝑃₀=0.994. ^eThe porosity is estimated from the pore volume determined using the desorption data at 𝑃/𝑃₀=0.994.