For most catalyst dispersions, stirring during the photocatalytic test is required to keep the catalysts particle adequately dispersed. Hence, a magnetic stirring plate is placed below the double walled beaker and a glass stirring bar is used within the photoreactor. In our experiments, we found that the use of a glass stirring bar can minimize adhesion of catalyst particles to the stirring bar, which can occur for common PTFE coated stirring bars.