Ti3+ self-doped TiO2 nanoparticles immobilized on self-pillared pentasil zeolite nanosheets: An efficient visible-light-driven degradation photocatalyst

Ti 3+ defective TiO 2 nanoparticles (TiO 2 -NPs) were synthesized through slow hydrolyzation of tetrabutyl titanate and low-temperature annealing, followed by loading on self-pillared pentasil (SPP) zeolite nanosheets to construct a TiO 2 /zeolite hybrid composite by solid-state dispersion. The obtained TiO 2 -NPs/SPP composite exhibited a distinct red-shift in the UV–vis absorption spectrum and a significantly reduced band gap due to the introduced Ti 3+ defects and the consequent oxygen vacancies (V O ), leading to an enhanced visible-light responsivity. The diverse porosity and house-of-cards nanosheet morphology of the SPP support not only promoted the efficient loading and stable immobilization of TiO 2 -NPs nanoparicles through micropore migration and surface adhesion but also endowed the adsorbability to the TiO 2 -NPs/SPP composite. The adsorptive photodegradation of methylene blue (MB) was used to evaluated the photocatalytic performance of TiO 2 -NPs/SPP, and a 95.6 % degradation rate of MB was observed after 3 h illumination with visible-light. The adsorptive effect strongly promoted the accessibility of MB molecules to the active TiO 2 species, leading to a remarkable enhancement in degradation efficiency. Moreover, a superior recyclability embodied in the retention of 96.4 % photocatalytic activity after three regeneration cycles indicated the TiO 2 -NPs/SPP composite to be practical for water pollutant degradation.