Degradation of 2,4,6-trichlorphenol by producing hydrogen using ultrasonic mist generated from photocatalysts suspension

摘要

Photocatalytic hydrogen production synergized with the oxidation of pollutants is an environmentally friendly and economical approach to generate clean energy and remove the pollution from environment. In this study, photocatalytic hydrogen production cooperating with 2,4,6-trichlorophenol (2,4,6-TCP) degradation have been reinforced by introducing an ultrasonic atomization. The degradation of 2,4,6-TCP in a mist of three photocatalysts (g-Csub3/subNsub4/sub, TiOsub2/sub, and Bisub2/subOsub3/sub) generated by ultrasonic atomization was performed under 254?nm ultraviolet (UVsub254/sub) light irradiation. The results showed that, under UVsub254/sub irradiation, three different photocatalysts (g-Csub3/subNsub4/sub, TiOsub2/sub, and Bisub2/subOsub3/sub) all accelerated both hydrogen production and 2,4,6-TCP degradation. Additionally, 2,4,6-TCP degradation and photocatalytic hydrogen production exhibited an obvious synergistic effect, since 2,4,6-TCP has a strong tendency to react with photo-generated holes and their second radicals so as to inhibit the recombination of carriers, and thus improved the efficiency of hydrogen production simultaneously. Moreover, by introducing ultrasonic atomization, the atomized droplets acted as micro-photocatalytic units to replace the macro-photocatalytic reaction reactor. Therefore, the mass transfer distance for free radicals was restricted and the utilization of light energy by photocatalysts was increased. Further, the reaction efficiency was improved. The results reveal environmentally friendly and economical potential of hydrogen production by photocatalytic degradation of 2,4,6-TCP in atomized droplets.