Adsorption and photocatalytic degradation performances of TiO2/diatomite composite for volatile organic compounds: Effects of key parameters

Abstract

The TiO2/diatomite composites with excellent adsorption and photo-degradation performances were leveraged to investigate the influences of calcination temperature and operating factors on their properties. The results showed that the calcination temperature was closely bound up with the crystallization of TiO2 and the specific surface area of composite. The composite with calcination temperature of 550 °C exhibited enhanced photocatalytic owing to the high surface area and small TiO2 crystallite size. A series of dynamic degradation experiments were conducted to investigate the effect of various operating parameters on acetone and p-xylene adsorption/degradation performances of the composite. The results illustrated that when the relative humidity (0–70%), gas flow rate (1–4 L/min), and VOC concentration (10–40 ppm) were set as the low values, the high total organic carbon degradation rate could be acquired. The total organic carbon degradation rate reached to a high value when the composite dosage was 3.76 mg/cm2. With the increase of light intensity (0.48–1.33 mW/cm2), the total organic carbon degradation rate presented an upward trend and then kept stable. The absorbent-photocatalyst hybrid TiO2/diatomite composite could be the promising VOC purification materials.