Effect of Preparation Condition of TiO_𝟐 Film and Experimental Condition on CO_𝟐 Reduction Performance of TiO_𝟐 Photocatalyst Membrane Reactor

Table 1

Physical properties of gas separation membrane.

	Thickness (𝜇m)	Mean pore size (nm)	Void ratio (-)	Permeability (m^2)
(1) Silica (SiO2) layer	0.2	0.4	0.27	5.44 × 10^−22
(2) γ-alumina (Al2O3) layer	2	4	0.44	8.88 × 10^−20
(3) α-alumina (Al2O3) layer	100	60	0.39	1.76 × 10^−17
(4) α-alumina (Al2O3) supporter	1000	700	0.40	2.45 × 10^−15

Silica layer is the top layer of this gas separation membrane.
γ-alumina layer is the second layer. α-alumina layer is the third layer.
α-alumina supporter is the bottom layer of gas separation membrane.