Atomically precise M <sub>15</sub> (M = Au/Ag/Cu) alloy nanoclusters: Structural analysis, optical and electrocatalytic CO <sub>2</sub> reduction properties
Along Ma, Jiawei Wang, Yifei Wang, Yang Zuo, Yonggang Ren, Xiaoshuang Ma, Shuxin Wang
Abstract
Herein, we report the overall structure of phosphine and mercaptan co-protected <strong>[Au<sub>7</sub>Ag<sub>8</sub>(SPh)<sub>6</sub>((<em>p</em>-OMePh)<sub>3</sub>P)<sub>8</sub>]NO</strong><strong><sub>3</sub></strong> (<strong>Au<sub>7</sub>Ag<sub>8</sub></strong>) nanocluster. As a point of comparison, we synthesize a nanocluster with the same structure but a different metal composition, <strong>[Au<sub>13</sub>Cu<sub>2</sub>(TBBT)<sub>6</sub>((<em>p</em>-ClPh)<sub>3</sub>P)<sub>8</sub>]SbF<sub>6</sub> </strong>(<strong>Au<sub>13</sub>Cu<sub>2</sub></strong>), as previously reported. We conduct a comprehensive comparison of their optical and electrocatalytic CO<sub>2</sub> reduction properties. The results reveal that the photoluminescence quantum yield (PLQY) of the Ag-doped <strong>Au<sub>7</sub>Ag<sub>8</sub></strong> nanocluster is 1.62%, which is seven times higher than that of the Cu-doped <strong>Au<sub>13</sub>Cu<sub>2</sub></strong> nanocluster (PLQY = 0.23%). Furthermore, the <strong>Au<sub>13</sub>Cu<sub>2</sub></strong> nanocluster demonstrates significantly enhanced catalytic selectivity for CO, with its CO faradaic efficiency ranging from 79.7% to 90.4%, compared to the <strong>Au<sub>7</sub>Ag<sub>8</sub></strong> nanocluster (CO faradaic efficiency: 67.2% to 77.7%) within the potential range of -0.5V to -1.1V. Structural analyses attribute the superior CO selectivity of <strong>Au<sub>13</sub>Cu<sub>2</sub></strong> to the copper dopant.