Efficient defect engineering and in-situ carbon doping in ultra-fine TiO2 with enhanced visible-light-response photocatalytic performance

Abstract

The wide bandgap and low photocatalytic efficiency are acknowledged as the main problems of the photocatalytic activities of TiO2. Herein, an effective strategy combing defect engineering and heteroatom doping is developed to expand the region covering visible light response and construct the active surface. A plasma-induced carbon doping (PICD) method is adopted to achieve a binary core-shell structure containing outer defect-layer shell of oxygen vacancy and inside crystalline anatase TiO2 core (~ 5 nm). The outstanding photocatalytic activity for visible-light-driven degradation of RhB and MO originates from narrowed bandgap (~ 2.30 eV) and improved photo-induced charge separation. Moreover, the excellent stability towards RhB degradation (100%) after 4 recycles exhibits the great potential applicability. RhB removal efficiency could reach to 100% even in the wide pH range from 3 to 11. Furthermore, the synergy effect by outside oxygen-vacancies layer and interstitial carbon doping enhanced the photoelectrochemical (PEC) performances significantly. This PICD technology can induce carbon doping and defect layer with active cites, which opens up a new way to design novel visible-light-responsive photocatalysis.