Pulsed‐Laser‐Driven CO 2 Reduction Reaction for the Control of the Photoluminescence Quantum Yield of Organometallic Gold Nanocomposites

Over the last decade, the CO 2 reduction reaction (CO 2 RR) has been increasingly exploited for the synthesis of high‐value raw materials in gaseous or liquid form, although no examples of CO 2 fixation in nanoparticle systems have been demonstrated. Herein, CO 2 fixation into solid nanomaterials by laser synthesis and processing of gold colloids in water, traditionally considered a green approach leading to ligand‐free nanoparticles without the formation of by‐products, is reported. If carbon monoxide‐rich gold nanoparticles are observable even after synthesis in deionized water, the presence of CO 2 derivatives in alkaline water environment leads to C 2 and C 3 coupling with the production of carboxylic acids as a typical CO 2 RR fingerprint. While laser processing of preformed gold colloids is selective for C 2 coupling, both C 2 and C 3 coupling to lactic acid are observed during pulsed laser ablation of a gold target. In the latter case, it is demonstrated that it is possible to synthesize photoluminescent organometallic nanocomposites in the blue spectral region with a quantum yield of about 20% under adequate experimental conditions. In this research, new pathways are offered to be explored in energetics, photonics, catalysis, and synthesis at the nanoscale.