Designing a smart acrylic photocatalyst coating loaded with N/C-doped TiO2@SiO2 core-shell by bio-based Tarem-rice husk waste for organic pollutant degradation

Abstract

Sustainable contaminations are the most important threat to water resources . In this research, nitrogen/carbon-doped silane-modified TiO 2 @SiO 2 heterojunction nanoparticles were synthesized and used in acrylic film to prepare photocatalytic polymeric film with a self-cleaning effect and fast drying speed. Tarem rice husk waste (TRHW) was used as a recyclable source of SiO 2 to fabricate cost-effectively SiO 2 core-structure. The TiO 2 lattice was prepared and modified with N&C-doping and modified TiO 2 @SiO 2 nanoparticles was synthesized through a one step process using calcination of APTES and TEOS . Results showed that the band gap energy of N&C-doped heterojunctions shifted to the red region from 2.98 eV (for TS) to 2.6 and 2.82 eV, respectively. They degraded methylene blue (MB) in aqueous solution by 97.19 % and 86.09 % under UV and 80.16 % and 72.84 % under solar light irradiation after 150 min, respectively. The N&C-doped nanocomposite demonstrated the best functional electron trapping efficiency (i.e. more photoactive components of hole, O· - 2 and OH·). The prepared nanostructures were applied to acrylic polymer and used to remove MB in a stain prepared on the film surface under light irradiation. Colorimetric analysis (ΔE * ) showed that the films containing N&C-doped TiO 2 @SiO 2 degraded MB for 93.4, 81.9 % and 84.8, 78.7 % under UV and solar light, respectively.