A high surface area magnetic photocatalyst with controlled pore size

Magnetic photocatalysts have the benefit of recoverability or even confinement/agitation using an oscillating magnetic field. A high surface area magnetic photocatalyst (HSAMP) was developed consisting of silica-coated barium ferrite and Degussa P25 titanium dioxide dispersed in an acid catalyzed silica xerogel. Through modifying the concentration of hydrofluoric acid catalyst during synthesis, three types ofHSAMPs were developed with resulting BET specific surface areas of 374, 543, and 550 m²/g. These HSAMPs were assessed for their photocatalytic activity by oxidizing a 6.5 mg/L phenol solution in comparison to Degussa P25 alone The resulting extent of photocatalysis was greater for the HSAMP than for Degussa P25 although the latter demonstrated a more rapid removal of the phenol parent compound The HSAMP was capable of removing nearly 100% of the nonpurgeable dissolved organic carbon for 6 repeated uses. Nearly 99% of the HSAMP mass was recoverable with a permanent magnet.