Regulating the Morphology Modification To Prepare the High Charge Separation Efficiency and Visible Light Responsive Dual-Type-II B-CN/H-TiO/BS-CN Heterojunction for Wastewater Treatment.

For the conventional type-II heterojunction photocatalyst, their photocatalytic activity is affected by the limited separation efficiency of electron-hole pairs, exquisitely designed heterojunction photocatalysts are highly prospective materials for inducing charge transfer efficiently. Typically, enhancing the separation efficiency of electron-hole pairs in photocatalysts has been a formidable challenge. Here, the hollow mesoporous TiO (H-TiO), the bulk g-CN (B-CN), and g-CN with bamboo shape (BS-CN) are prepared by simple processes. Among them, it is surprising to find that the band structure of g-CN can be regulated and controlled by adjusting its structure. The B-CN/H-TiO/BS-CN (CNTOCN) dual-type-II heterojunction photocatalyst and B-CN/H-TiO (CNTO) type-II heterojunction photocatalyst are designed to improve the separation efficiency of electron-hole pairs. The superiority of CNTOCN dual-type-II heterojunction photocatalyst is demonstrated by the photocatalysis experiment, the band structure analysis, and the photoelectric characterization. The results show that CNTOCN (0.8428 h) has much higher photocatalytic activity than H-TiO (0.0812 h), B-CN (0.3569 h), and CNTO (0.5934 h). The improvement of photocatalytic activity is ascribed to the establishment of the dual-type-II heterojunction charge transfer mechanism. This work presents an approach to designing efficient dual-type-II heterojunction photocatalysts for the sustainable conversion of solar energy to photodegrade dyes in dyeing wastewater.