“…To attain better applicability and improve the recyclability of semiconductor photocatalysts on a larger and economically feasible scale, the immobilization of metal oxide/ sulfide nanomaterials on some suitable substrate has been an increasing area of research. Photocatalytic nanomaterials have been coated on adequate support materials such as SiO 2 , glass beads, optical fibers, magnetite particles, zeolites, and polymeric materials, among others [27,28,33,34,37,[105][106][107][108]. For example, when small (< 15 nm) TiO 2 particles are supported on sub-micron size SiO 2 particles, their separation from aqueous media becomes easier due to the overall increase in particle size of silica-supported TiO 2 , unlike the unsupported TiO 2, which is difficult and costly to separate from reaction media, be it through centrifugation, decantation or filtration.…”