Synthesis of Graphene Oxide and Titania Nanorods. Graphene oxide (GO) was synthesized according to the procedure reported by Hummers et al. with additional purification via dialysis. Titania nanorods (TNRs) were synthesized following the seeded-growth approach reported by Gordon et al. using a Thorlabs PM100 powermeter, equipped with a Thorlabs S120 UV sensor. To prevent heating of the samples the housing of the setup was ventilated by an electrical fan.