Formaldehyde is a typical volatile organic compound(s) (VOCs) of indoor air pollutants. Surface plasmonic resonance (SPR) photocatalysts can absorb visible light

which allows solar light driven photocatalytic removal of formaldehyde from air to occur at room temperature and ambient pressure. However

very few studies on Au/TiO2 photocatalyst of SPR for removal of formaldehyde from air are reported

of which the apparent kinetic study is of significance for the design of SPR catalysts and the applications to removal of VOCs pollutants. This paper studies the kinetics of photocatalytic oxidation of formaldehyde over plasmonic Au/TiO2 under LED visible light. Effects of visible light sources with various wavelengths

light intensity and relative humidity of reaction gas on kinetics of visible-light photocatalytic oxidation of formaldehyde over Au/TiO2 are investigated. Based on the experimental analyses

the apparent kinetics constant of k(I

H) for the LED visible light driven photocatalytic oxidation of formaldehyde is achieved. It suggests that

under conditions of 13% relative humidity and 38.5 mW·cm-2 of blue light intensity

the formaldehyde conversion is 77%

almost 5 times that under dark. Under LED irradiations of red

green

blue and white light

the conversions of formaldehyde increases rapidly

slowly

and keeps steady with light intensity. Under the same conditons of light intensity (less than 42 mW·cm-2) and relative humidity

the conversions of formaldehyde under LED red

green and blue light

are approximate

and the conversion under white light is relatively lower than that of the rest three. At dry condition

the converion of formaldehyde is almost 0. However

at wet condition

the conversions under light or under dark exist (above zero)

and that under light is higher than under dark. The conversion as a function of relative humidity behaves similarily under various light sources. The conversion reaches the maximum at 21.9% of relative humidity

followed by almost being steady at 80%. Apparent kinetic parameters k(I)H

k(H)I and k(I

H) and the kinetic equations by fitting above data related to red

green

blue and whilte light are achieved and established.