A 2D/3D g-C3N4/BiOI heterostructure nano-sphere with oxygen-doped for enhanced visible light−driven photocatalytic activity in environmental remediation

Adjusting the desired structure and heterojunction interface of photocatalytic materials using a facile and efficient strategy is still challenging. In this study, a novel two-dimensional/three-dimensional (2D/3D) oxygen-doped g-C 3 N 4 /BiOI heterostructure nano-sphere (O-g-C 3 N 4 /BiOI) was successfully prepared by a facile solvothermal method for the degradation of nondye organic contaminants. Its composition , morphological characteristics, chemical structure and electrochemical properties have been measured. The result shows the introduction of oxygen doping (O-doping) causes a new defect energy level, extends the light absorption range, and the formation of heterojunction enables the effective separation of photo-generated carriers. Under visible light irradiation, the optimum ratio of O-g-C 3 N 4 /BiOI (2:1) exhibited 100% removal efficiency of bisphenol A within 80 min, which was about 9.1, 2.33, 3.45, and 1.6 times that of pure g-C 3 N 4 , O-g-C 3 N 4 , BiOI, and O-doped-poor heterostructure, respectively. Based on the identified intermediates, the photocatalytic mechanism of O-doped O-g-C 3 N 4 /BiOI (2:1) was also revealed. This finding suggested that the synergistic effect between 2D/3D heterojunction and O-doped greatly promoted visible light photoabsorption and photoinduced carrier separation efficiency with a prolonged lifetime, which was confirmed by multiple optical and electrochemical analyses . This study could bring new opportunities for the rational design of highly efficient photocatalysts by combining 2D/3D heterojunctions with O-doped in environmental remediation.