Bone powder decorated TiO2 and ZnO nanoparticles: The first investigation of NOx degradation by solar light and visible light-driven photocatalyst

Abstract

This study performed the transformation of food waste and resin into the valuable photocatalyst which was applied in the NOx decomposition. Bone waste was used as the agricultural waste because of its high CaCO3 compositions. In this study, heterojunction composites were synthesized by calcination ZnO and TiO2 with chicken bone and pork bone (ZnO@Pb, ZnO@Cb, TiO2@Pb and TiO2@Cb). The degradation of NOx can be obtained from 63.30% to 81% under solar light irradiation from the concentration of NOx at 550 ppb. TiO2 decorated with pork bone under visible light gives the best NOx removal efficiency at 70%, with the concentration of NOx at 1800 ppb (1.8 ppm). Furthermore, the trapping experiments confirm that h+ and e− have an impact on the degradation of NOx. The addition of bone waste also shortened the band gap of TiO2/ZnO from 0.649 to 1.266 eV with the microcube formation. This study provides important information on cost-less catalysts for degrading nitrogen oxide (NOx) under solar light and visible light.