Engineered “Molecule‐Junction” to Transport Photo‐Generated Electrons for CO ₂ Reduction to Ethane

Abstract

ABSTRACT Targeted transport of electrons is essential to enable the photoreduction process efficiently, which remains a significant challenge in current research. Constructing “molecule‐junction” between photocatalyst and metal active sites is expected to achieve the precise directional electron transfer. 2‐Mercaptonicotinic acid (H 2 L), with both sulfhydryl groups (─SH) and a conjugated pyridine ring, was introduced as the intermediary to build “molecule‐junction” connecting Ni‐doped BiOCl (Ni/BOC) and Au NPs (denoted as Ni/BOC‐H 2 L‐Au). XPS and XAFS results confirm the existence of Bi─S and Au─S bonds, which verify that the “molecule‐junction” of Bi─H 2 L─Au have been successfully constructed in Ni/BOC. Due to the unique structure of Ni/BOC‐H 2 L‐Au, it showed excellent performance in CO 2 photoreduction. In the absence of sacrificial agents, the ethane (C 2 H 6 ) yield (155.4 µmol g −1 h −1 ) and selectivity (85.8%) exceeded most of the reported photocatalysts. The combined theoretical and experimental analysis demonstrates that the “molecule‐junction” establishes a directional electron transfer pathway (Ni/BOC→H 2 L→Au NPs), which significantly enhances charge separation efficiency and promotes targeted electron accumulation at Au NPs active sites, thereby boosting C 2 H 6 production via CO 2 photoreduction. This work proposes a viable strategy for designing efficient photocatalysts for high‐value C 2+ product synthesis.