One-step preparation of TiO2–carbonized medium-density fiberboard for volatile organic compound photodegradation

Photocatalytic carbonized medium density fiberboard (MDF) was prepared by one-step carbonization with titanium tetraisopropoxide (Ti-tip) as a TiO2 precursor. Anatase TiO2 was formed at carbonizing temperatures of 600 to 800 °C. However, at > 900 °C, most crystalline TiO2 was rutile. Ti-tip-treated carbonized MDF (c-MDF) showed outstanding formaldehyde reduction performance with complete removal of formaldehyde from the chamber in 1 to 3 days. However, with non Ti-tip-treated c-MDF, formaldehyde remained after 20 days. No toluene was detected after 3 h on 50% Ti-tip-treated c-MDF, while toluene was continuously detected with other samples (10% and 5% Ti-tip-treated c-MDF, and untreated c-MDF). After 9 h ultraviolet exposure, toluene was completely reduced on 10% and 50% Ti-tip-treated c-MDF; reduction was only 20% on untreated c-MDF. In addition, c-MDF/TiO2 prepared at 800 and 900 °C had significantly higher photocatalytic performances compared to those obtained at lower carbonization temperatures. Based on the results, the combination of 10% Ti-tip treatment and carbonizing at 800 °C provided the optimum photodegradation capacity for formaldehyde and toluene.