Photocatalytic degradation and rate constant prediction of chlorophenols and bisphenols by HPWO/GR/TiO composite membrane.

Photocatalysis is a promising approach to remove highly toxic and refractory aromatics pollutants. However, developing highly active photocatalyst is a long-standing challenge for pollutant degradation. This study addressed this challenge by developing GR (graphene)/TiO and HPW (HPWO)/GR/TiO membranes by sol-gel method. The removal efficiencies of HPW/GR/TiO (the doping of 1.0% HPW) membrane for chlorophenols (including o-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol) and bisphenols (such as Bisphenol A, Bisphenol AP, Bisphenol AF, and Bisphenol S) were up to 97.02-82.71% and 93.28-68.63% with simulated sunlight radiation for 5 h, respectively. Compared with GR/TiO composite membrane, HPW/GR/TiO remarkably accelerated the formation rates of O and OH, due to the simultaneous transfer of photo-generated electrons (generated by TiO) to GR and HPW. In addition, the activity of the HPW/GR/TiO membrane did not decline noticeably after 10-time recycle. Furthermore, the photocatalytic degradation reaction rate constants (k) of phenols by HPW/GR/TiO membrane were calculated, and those for other chlorophenols and bisphenols were predicted using a quantitative structure-activity relationship model. The HPW/GR/TiO membrane developed in this study poses high potential as an ideal photocatalyst for removal of phenolic pollutants in wastewater.