Lattice reconstruction of one-dimensional mineral to achieve dendritic heterojunction for cost-effective nitrogen photofixation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2021-06, Vol.414, p.128797, Article 128797
• Main Authors: Li, Xiazhang, Shi, Haiyang, Zuo, Shixiang, Gao, Bingying, Han, Chaoya, Wang, Tianshi, Yao, Chao, Ni, Chaoying
• Format: Article
• Language: English
• Subjects: Heterostructure; Nitrogen fixation; Palygorskite; Photocatalysis; Reconstruction
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.128797

•Cost-effective hierarchical photocatalyst developed by 1-D natural mineral.•Incorporation of Fe into the Pal framework reduces the band gap.•In situ precipitated Fe2O3 enhances the light absorption and active sites.•Z-scheme Fe2O3/Fe-Pal heterojunction retains high charge potential for N2 reduction. Achieving sustainable ammonia synthesis strategies to replace traditional Haber-Bosch process remains a significant challenge; however, photo-driven catalysis system based on natural nano-minerals promises a great potential to meet the challenge. In our work, an acid-treated natural one-dimensional clay palygorskite (Pal) is substituted with iron ion to realize lattice reconstruction via a microwave-hydrothermal process. The modified Pal with Fe substitution (Fe-Pal) has the original crystal structure with a narrowed band gap. As the mass ratio of Fe is beyond 30 wt%, extra Fe2O3 precipitates on the Pal surface and the nanocomposite resembles a dendritic heterostructure, which effectively enhances visible light absorption and exposes abundant active sites for synergistic adsorption and photo-activation of nitrogen. The 60 wt% Fe-Pal nanocomposite exhibits a remarkable photocatalytic fixation capability for nitrogen under the visible light. Density function theory calculation is employed to help elucidate the photocatalytic mechanism. Our findings potentially provide a green and cost-effective way to synthase nitrogen.