Photocatalytic Degradation of Phenol Using Immobilized TiO₂ Nanotube Photocatalysts

Figure 4

Photocatalytic degradation of phenol under different conditions. Conditions: catalyst comprised TiO₂ nanotubes, silica gel, and colloidal silica in the ratio of 3 : 2 : 20; catalyst loading = 1 g/L, air flow rate = 0.3 L/min, and initial phenol concentration = 30 mg/L. (● = in darkness, in the absence of the catalyst, ▲ = in darkness, in the presence of the catalyst, and ◆ = UV irradiation in the absence of the catalyst).