Large-scale and solvent-free synthesis of magnetic bamboo-like nitrogen-doped carbon nanotubes with nickel active sites for photothermally driven CO2 fixation

Abstract

The development of a method for the large-scale and solvent-free preparation of hierarchical pore single-atom catalysts is highly desirable but challenging. Herein we report the fabrication of bamboo-like nitrogen-doped carbon nanotubes comprising both Ni single atoms and Ni nanoparticles (Ni-SAs/NPs@BNCNTs) via combining the ball milling and pyrolysis methods. Due to the nature of the carbonaceous species and the plasmonic excitation of the Ni nanoparticles, the as-obtained Ni-SAs/NPs@BNCNTs exhibit excellent photothermal performance, with the reaction solution temperature rising to 70.4 °C at a light intensity of 200 mW cm⁻². The semiconductor properties of nickel/nitrogen-doped carbon (Ni–N–C) facilitate the generation of photogenerated electron–hole pairs. Remarkably, the Ni-NPs/SAs@BNCNTs act as a photothermal catalyst for the N-formylation of amines with CO₂ and phenylsilane and exhibits prominent catalytic performance (yield: 95% and selectivity: 96%). This study provides unique insights into the facile and scalable preparation of single-atom catalysts and their photothermal catalytic applications in CO₂ fixation.