A biomimetic approach towards the synthesis of TiO₂/carbon-clay as a highly recoverable photocatalyst

Efficient use of sunlight for cleaning polluted water is a sustainable way of addressing the key environmental problems. Photocatalysts with high adsorption, good photocatalytic ability and highly recoverable performance are highly desirable to effective clean organic contaminates from water. In this study, a highly recoverable TiO₂/carbon-clay photocatalyst was prepared by immobilizing TiO₂ (commercial P25) on strong adsorbent (clay) via a bio-mimetic coating strategy and followed by a carbonization process. Superior separability of TiO₂/carbon-clay was achieved by simple gravity sedimentation, in which most of TiO₂/carbon-clay settled within 5 min and all the particles settled within 2 h. The obtained TiO₂/carbon-clay composites possessed a maximum adsorption capacity (Q_max) of 95.4 mg/g and showed high photocatalytic activity, which removed 99% dye within 30 min under simulated sunlight irradiation. This TiO₂/carbon-clay composites also exhibited excellent durability and no apparent reduction of dye removal efficiency was observed after 5 cycles reuse.