Enhanced photocatalytic degradation performance of cornstalk templated TiO2 towards ciprofloxacin in hospital wastewater by the synergistic effect of the (101)/(001) facets coexposed and NiO cocatalyst

Abstract

In this work, a novel TiO2 photocatalyst (marked as yNiO/5 F-CSTG) was designed and synthesized through a solvothermal pathway assisted with a bio-template, which prefectly combined the strategy of crystalline facet engineering and co-catalyst. The experiment and characterization results indicated that the co-exposure of {101}/{001} facets over TiO2, surface heterojunction and NiO cocatalysts jointly promote the photocatalytic performances, which can be attributed to the high separation efficiency of electron-hole pairs. Additionally, the introduction of morphology regulator (i.e., glycerinum) induced the directional growth of TiO2，being beneficial to broaden the responsive range of visible light. Consequently, compared with pristine TiO2 and CST, the photocatalytic removal rate of 1NiO/5 F-CSTG towards CIP increased ∼24.8 and ∼2.6 times. Besides, for tap-water and hospital sewage, its photocatalytic removal rate reached 89.15 % and 56.32 %, respectively. DFT calculation showed that the F- doping into TiO2 led to the formation of impurity energy level, which contributed to the electron transfer between the co-exposure facets of {101}/{001}. This work provides certain valuable hints for the development of bio-templated photocatalysts.