Photocatalytic studies using a very low surface area catalyst: TiO2 over CaCO3 from waste shell (Pomacea canaliculata) in paraquat degradation

Calcination of shell waste and subsequent processing resulted in CaCO3 powder that was used as the catalyst support for TiO2/CaCO3 catalyst. The catalyst has been characterized by scanning electron microscopy, BET measurements, X-ray diffraction, UV-visible diffused reflectance spectroscopy and Fourior transform infrared spectroscopy to elucidate the catalyst’s properties. The TiO2 over CaCO3 catalyst has been used as a photocatalyst in paraquat removal under optimized conditions of calcination temperature, TiO2 loading method, loading content of Ti component, loading content of TiO2 in the catalyst and light irradiation. The results show that all the experimental parameters significantly affect paraquat removal efficiency of the catalyst. The calcination temperature and TiO2 loading method show the most significant effect.