Highly efficient photodegradation of various organic pollutants in water: Rational structural design of photocatalyst via thiol-ene click reaction

It is of great importance to control the structure of titanium dioxide (TiO2)-based photocatalysts for the elimination of organic pollutants in water. The intrinsic highly efficient and ubiquitously employed click reaction is currently underutilized by environmental scientists. In this paper, we report the use of thiol-ene click reaction for the facile preparation of TiO2-bacterial cellulose (BC) composite using two chemically functionalized precursors, i.e. thiol-functionalized uniform TiO2 nanoparticles of different sizes and vinyl-functionalized bacterial cellulose. Results from the electron spin resonance experiments showed that one could easily increase the number of main oxidative species, i.e. %OH radicals, of the BC/TiO2 composite by using smaller TiO2 nanoparticles and further nitrogen doping, exhibiting higher photocatalytic reactivity. Consequently, our photocatalysts with well structural control have demonstrated remarkably higher reactivity for the degradation of various organic molecules than many previously reported TiO2-based photocatalysts. With more virtues of excellent reusability and stability, our sample has shown its great potential for the removal of organic molecules in real polluted water. Our work has also presented a novel methodology for the design of inorganic/organic composite materials with readily tunable structure and composition since our protocol could be easily applied to other systems.