Preparation of TiO2–based hollow microspheres by spray drying and their use as novel active pigments for photocatalytic coatings

The use of TiO2 nanoparticles in organic-based photocatalytic coatings imposes several challenges: poor activity under visible light, binder photo-degradation, need for UV activation and toxicity concerns. Here we present a scalable two-step synthesis route to prepare TiO2-based hollow microspheres (HoS) as alternative photocatalyst commercial nanoparticles. or WO3-doped (3 mol% WO3) are synthesized via template-assisted spray-drying followed by calcination. structure composition the powders characterized their performance is assessed using methylene blue photo-degradation irradiation model reaction. XRD analysis reveals presence anatase TiO2(B) phases, indicating heterostructured nature samples. results dye tests confirm functionality HoS. Moreover, introduction WO3 (TiO2/WO3 HoS) leads an enhancement performance, approaching that (Aeroxide P25, ~21 nm) most active TiO2/WO3 HoS incorporated into acrylic formulation resulting tested towards pollutant abatement light. A coating containing P25 undergoes process where degradation increased exposure rise catalytic but possibly at expense stability. By contrast HoS-acrylic exhibit similar initial coatings, does not cause same partial photo-degradation.