Anchoring of Metal Complexes on Au<sub>25</sub> Nanocluster for Enhanced Photocoupled Electrocatalytic CO<sub>2</sub> Reduction
Jiangtao Zhao, Abolfazl Ziarati, Arnulf Rosspeintner, Thomas Bürgi
Abstract
Abstract Atomically precise Au nanoclusters (NCs) with discrete energy levels can be used as photosensitizers for CO 2 reduction. However, tight ligand capping of Au NCs hinders CO 2 adsorption on its active sites. Here, a new hybrid material is obtained by anchoring of thiol functionalized terpyridine metal complexes (metal=Ru, Ni, Fe, Co) on Au NCs by ligand exchange reactions (LERs). The anchoring of Ru and Ni complexes on Au 25 NC (Au 25 −Ru and Au 25 −Ni) leads to adequate CO 2 to CO conversion for photocoupled electrocatalytic CO 2 reduction (PECR) in terms of high selectivity, with Faradaic efficiency of CO (FE CO ) exceeding 90 % in a wide potential range, remarkable activity (CO production rate up to two times higher than that for pristine Au 25 PET 18 ) and extremely large turnover frequencies (TOFs, 63012 h −1 at −0.97 V for Au 25 −Ru and 69989 h −1 at −1.07 V vs. RHE for Au 25 −Ni). Moreover, PECR stability test indicates the excellent long‐term stability of the modified NCs in contrast with pristine Au NCs. The present approach offers a novel strategy to enhance PECR activity and selectivity, as well as to improve the stability of Au NCs under light illumination, which paves the way for highly active and stable Au NCs catalysts.