Impact of silica nanoparticles architectures on the photosensitization of O2 by immobilized Rose Bengal

Transforming light into chemical energy has been widely studied to design ecofriendly, cost-effective and sustainable synthetic approaches. The heterogenization of organic photocatalysts is a well-known strategy providing efficient solid supported catalysts. One of the most suitable solid as support is silica nanoparticles (NPs). This research note highlights the impact of silica nanoparticles morphology on a representative photochemical process that is the photooxidation of citronellol, involving oxygen sensitization. Three architectures of silica NPs were investigated: Nanospheres (NS), Core-Shell (CS) and Urchins (U). Their surfaces were functionalized with ammonium moieties allowing the immobilization of Rose Bengal (RB) by electrostatic interactions. The heterogenized RB on the various supports displayed different activities in the production of singlet oxygen, CS being the best support in terms of activity, recyclability and dye immobilization rate.