《Adv. Energy Mater.》: Induced C−C Coupling by Amorphous-Crystalline Hybrid Structure for Selective CO₂ Photoreduction into C₂ Fuels

Dongpo He,⁺ Guangbing Huang,⁺ Jun Hu,⁺ Jinyu Ding, Wenxiu Liu, Liang Chen*, Wensheng Yan, Junfa Zhu, Shan Zhu, Qingxia Chen*, Xingchen Jiao*, and Yi Xie

Selective photoreduction of carbon dioxide (CO₂) into high-value C₂ products remains a formidable challenge due to the elusive C−C coupling step. Herein, we first introduce the novel concept that an amorphous-crystalline hybrid structure can galvanize previously inert metal atoms, thereby establishing highly active dual sites. This ingenious configuration promotes the C−C coupling, paving the way for CO₂ photoreduction into C₂ products. Taking the Bi₂MoO₆ nanosheets anchored by amorphous FeOOH species as an example, X-ray photoelectron spectroscopy (XPS) spectra and X-ray absorption near edge structure (XANES) spectra and density functional theoretical (DFT) calculations confirm the electron transfer from FeOOH to Bi₂MoO₆ nanosheets. Thus, the introduction of FeOOH activates the nonoperative Bi sites for the construction of Bi−Mo dual sites, verified by the in situ XPS spectra and DFT calculations. Gibbs free energy calculations revealed the formation energy barrier of C−C coupling was hugely lowed from 3.41 to 0.45 eV thanks to the presence of FeOOH species. Therefore, the FeOOH-Bi₂MoO₆ nanosheets are a game changer, delivering the sole liquid product, acetic acid, with an impressive electron selectivity of approximately 86.9%. In contrast, the Bi₂MoO₆ nanosheets lag behind, only capable of producing carbon monoxide from CO₂ photoreduction.

Figure 1. Schematic illustration for CO₂ photoreduction into CH₃COOH over the catalyst with amorphous-crystalline hybrid structure.