N-doped carbon dots-modulated interfacial charge transfer and surface structure in FeNbO4 photocatalysts for enhanced CO2 conversion selectivity to CH4

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-10, Vol.498, p.155576, Article 155576
• Main Authors: Cheng, Yuanyuan, Jabeen, Sobia, Lei, Siwei, Liu, Naiyun, Liu, Yixian, Liu, Yunliang, Li, Yaxi, Wu, Xin, Tong, Zhuang, Yu, Jingwen, Cao, Peng, Kang, Zhenhui, Li, Haitao
• Format: Article
• Language: English
• Subjects: Carbon dots; CO2 reduction; Electron transfer; Energy conversion; Photocatalyst
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155576

We utilized the functionalization of N-CDs to systematically modulate the structure and electron transfer behavior of FeNbO4 catalysts for enhanced CO2 conversion selectivity to CH4 in an aqueous solution without any sacrificial agent. This approach shows promise in creating an efficient photocatalyst for the reduction of CO2, allowing for tunable CH4 product selectivity. [Display omitted] •Synthesis of N-doped carbon dots/FeNbO4 photocatalyst using microwave-assisted hydrothermal method.•Increased lattice strain and oxygen vacancies enhance the CO2 adsorption on N-CDs/FeNbO4 photocatalyst’s surface.•Accelerated interfacial charge transfer resulting from the introduction of N-CDs promotes charge separation and transfer.•Photocatalytic conversion of CO2 to CH4 with high activity and selectivity is achieved. The photocatalytic carbon dioxide reduction reaction (CO2RR) is an innovative and reliable technology to address the issues of energy shortage and climate change simultaneously. However, issues such as insufficient light absorption, rapid electron-hole recombination and low surface activity during CO2RR severely limit the catalysts’ efficiency for photocatalysis. In this study, we present nanohybrid N-CDs/FeNbO4 catalysts to overcome these challenges and achieve high-efficient photocatalytic conversion of CO2 to CH4. The enhancement process starts with the introduction of modified N-CDs, which have a broad light absorption capability. These N-CDs also help to modulate the interfacial charge transfer kinetics, leading to improved charge separation and transfer. This, in turn, enhances the multielectron transfer conversion selectivity of CO2 to CH4. Meanwhile, CO2 adsorption on the photocatalysts is increased due to the creation of oxygen vacancies and lattice stresses resulting from the introduction of N-CDs. This work presents a new approach for improving the photocatalytic performance by adjusting surface structure and interfacial behaviors.