Integrated adsorption and photocatalytic degradation of VOCs using a TiO₂/diatomite composite: effects of relative humidity and reaction atmosphere

Abstract

The optimal relative humidity condition for VOC degradation is related to the length of the carbon chain of VOCs.

Photocatalytic Degradation of VOC Waste Gas in Petrochemical Sewage Fields

“…The impact of RH on the VOC conversion rate is shown in Figure . The surface of the water molecules in the gas adsorbs a small amount of VOCs so that the VOC molecules can stably reach the surface of the catalyst for photocatalytic reaction and improve the conversion rate . Therefore, in the process of RH gradually increasing from 69 to 74%, the conversion rate of the VOCs is improved, and the maximum is 92.73%.…”

Efficient degradation of VOCs using semi-coke activated carbon loaded ternary Z-scheme heterojunction photocatalyst BiVO4–BiPO4–g-C3N4 under visible light irradiation

“…Relative humidity is an important factor affecting the degradation of VOCs. 65 It can be seen from the figure that the degradation rate of the composite material under different relative humidity is not very different, which shows that the composite material has high adaptability to the environment. The degradation rate is the best under the condition of relative humidity of 60%, mainly because the appropriate relative humidity water will not cause blockage of the pore structure of sac, and there is enough water to ensure that the photocatalyst reacts with water to generate enough active species.…”

Photocatalytic degradation of VOCs from air stream using Mo:TiO2/GAC nanocomposites

“…This phenomenon can be explained by the fact that H 2 O in low amounts as a major source of OH • radicals (valuable active species that are generated in advanced oxidation processes and play an active role in the reactions) helps the degradation efficiency to be improved. On the other hand, at higher H 2 O concentrations, the excess water molecules compete with chloroform in adsorption on the surface of GAC [57][58][59]. The ozone production would also be restricted by the higher concentrations of H 2 O when UV was used [60,61].…”

“…Specifically, the effect of VOCs concentration on RE was controversial [1,27,64]. Some of the researchers believe that higher numbers of pollutant molecules benefit the RE due to the precursor supply for the production of more active species, but others believe the opposite [17,59,64,65]. Although indicators like OH radical yield per molecule and specific input energy have recently been introduced to address the issue, the challenges are continuing [66][67][68].…”