N-doped rutile TiO 2 nanorod@g-C 3 N 4 core/shell S-scheme heterojunctions for boosting CO 2 photoreduction activity

• Published in: Catalysis science & technology Vol. 13; no. 3; pp. 898 - 909
• Main Authors: Gu, Haohui, Liang, Feng, Wang, Xiaohan, Wu, Shuaibing, Lv, Gongye, Zhang, Haijun, Zhang, Shaowei, Lu, Lilin, Dong, Zhijun
• Format: Journal Article
• Language: English
• Published: 06.02.2023
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/D2CY01839J

The design of heterojunction photocatalysts is regarded as a very effective method to solve the high recombination rate of photogenerated charge carriers for CO 2 photoreduction into hydrocarbons, and interface engineering is urgently required to achieve high efficiency. Herein, graphitic carbon nitride (g-C 3 N 4 , CN) was uniformly grown on the surface of nitrogen-doped rutile TiO 2 (NT) nanorods by in situ deposition, and a NT@CN core/shell step-scheme (S-scheme) heterojunction system composed of NT nanorods and g-C 3 N 4 was synthesised. The as-synthesised heterojunction containing 55 wt% g-C 3 N 4 delivered the highest CO 2 photoreduction activity (33.35 μmol g −1 for CO) without additional cocatalysts or external sacrificial agents, which was 7.1 times higher than that of bare NT nanorods. This improved CO 2 reduction activity was attributable to the large surface area and impactful S-scheme heterostructure, which imparted the catalyst with sufficient visible-light harvesting ability, promoted the segregation and transformation of the photoinduced charge pairs, and enhanced the redox ability of the carriers. Concurrently, the NT@CN photocatalyst exhibited excellent reusability and stability. This work offers a new basis for designing and preparing rutile TiO 2 -based S-scheme heterojunctions with enhanced CO 2 reduction performance.