Detachable photocatalysts of anatase TiO2 nanoparticles: Annulling surface charge for immediate photocatalyst separation

Herein, we report the synthesis and characterization of TiO2 nanoparticles (NPs) as efficient photocatalysts via a modified sol-gel method. A temperature-dependent study is conducted to evaluate the characteristics of the nanoparticles via XRD, XPS, DLS, UV-vis, N2 sorpometry and TEM techniques. The efficiency of the as-prepared photocatalyst is then tested for the photocatalytic degradation of Rhodamine 6G dye (R6G). The study covers a range of pH values and the maximum efficiency reported here is above 92.5% at pH = 9.17. The main focus of this study is to establish a method that can be industrially used to enable the separation of the photocatalyst after the experiment is performed, regardless of the type of the photocatalyst. This is achieved by triggering the sedimentation of the photocatalyst by means of annulling the NPs surface charge. A complete separation of the photocatalyst from the reaction medium is achieved in 3 min. This method has proven to be simple, rapid, economically feasible and can be applicable to a wide range of photocatalysts.