Chitosan-based recyclable composite aerogels for the photocatalytic degradation of rhodamine B.

Abstract TiO2 based photocatalyst with sufficient reusability for the degradation of water pollutants remains a challenge. Here, we report a composite chitosan-based aerogel containing TiO2 nanoparticles, multiwalled carbon nanotubes and layered silicate rectorite with sufficient mechanical strength for Rhodamine B degradation. The aerogels with homogeneous oriented lamellar structure were successfully prepared via a unidirectional freeze-casting technique. As-prepared aerogels showed specific surface area of 84.59 m2/g. The addition of rectorite and carbon nanotubes accelerated the photodegradation and rectorite significantly enhanced the overall mechanical performance. Rapid degradation of rhodamine B (95% in 100 min) was observed on aerogels with 2 wt% and 4 wt% of rectorite. After 3 cycles, 75% degradation of Rhodamine B was achieved with CTCR4, confirming its reusability. Thus, the composite chitosan aerogels show high photocatalytic degradation efficiency towards Rhodamine B during cycle use.