Enhanced Photoreduction Activity of Carbon Dioxide over Co₃O₄/CeO₂ Catalysts under Visible Light Irradiation

Table 2

Mean methanol and ethanol yield on Co₃O₄/CeO₂ catalysts under visible light irradiation ( > 400 nm).

Catalyst mass fraction of Co3O4 doping (%)	Mean yield of methanol μmol·h^−1	Mean yield of ethanol μmol·h^−1
0 (CeO2)^(a)	0.68	2.77
1.0^(a)	1.51	2.87
2.0^(a)	1.5	3.95
8.0^(a)	1.22	3.15
10.0^(a)	1.18	2.43
100 (Co3O4)^(a)	0	0
5.0^(a)	1.52	4.75
5.0^(b)	0.91	2.22
5.0^(c)	0.75	2.16

0.30 g catalysts reacted in 300 mL solution of (a) 0.1 M NaOH + 0.1 M Na₂SO₃, (b) 0.1 M Na₂CO₃ + 0.1 M Na₂S, and (c) 0.1 M Na₂CO₃ + 0.1 M Na₂SO₃. A 300 W Xenon lamp ( > 400 nm) irradiated for 5 hours.