MOF derived carbon modified porous TiO2 mixed-phase junction with efficient visible-light photocatalysis for cyclohexane oxidation

Abstract In this paper, carbon modified porous TiO2 mixed-phase junction was successfully fabricated by using the MIL-125(Ti)-P25 composite as the precursor. The porous TiO2 possessed abundant pores and large surface area inherited from its precursor during a simple one-step pyrolysis in a crucible, and the modified TiO2 showed catalytic activity for photocatalytic cyclohexane oxidation. Moreover, the ratios of anatase/rutile TiO2 and carbon contents in the modified TiO2 mixed-phase junction can be regulated conveniently. Among the mixed-phase porous TiO2, the C TiO2–4 sample containing 12.4 wt% rutile TiO2 presented the best photocatalytic activity, which was also much better than those of carbon modified pure anatase or rutile TiO2 . The carbon modification was characterized by carbon doping and surface carbon species, which played the vital role in enhancing the photocatalytic activity of the mixed-phase TiO 2. Carbon doping into TiO2 lattice can effectively reduce its band gap energy and extend the light response range. The carbon species on the TiO2 surface can improve the light absorption efficiency and promote the transport of photogenerated electrons. Free radicals capture experiments demonstrated that •OH and •O2− radicals were important active species in the cyclohexane oxidation reaction . This work provides a MOF-mediated P25-assisted synthesis strategy that may guide the design of other photocatalysts .