Porous ZnO Microspheres Grafted with Poly-(N-isopropylacrylamide) via SI-ATRP: Reversible Temperature-Controlled Switching of Photocatalysis**

We report on the fabrication of porous ZnO microspheres (pZnO MSs) grafted with thermo-responsive polymers of poly(N-isopropylacrylamide) (PNIPAM) via surface-initiated atom transfer radical polymerization (SI-ATRP) for photocatalysis applications. Photodegradation of Rhodamine B (Rh-B) is used to evaluate the photocatalysis performance of pZnO MSs grafted with PNIPAM (pZnO MSs-PNIPAM). The results show that pZnO MSs-PNIPAM exhibits a reversible temperature-controlled photocatalysis activity and good recycling performance. By adjusting the environmental temperature, the photocatalysis property of pZnO MSs-PNIPAM can be turned on/off, resulting in a temperature-controlled switching function of the obvious/unobvious photocatalysis performance below/upon the lower critical solution temperature (LCST) of PNIPAM. Additionally, the dispersion property of pZnO MSs-PNIPAM in water can also be regulated by changing the environment temperature, demonstrating the potential applications in that of photocatalysis-related fields for the graft systems.