Increasing electron density through an n-type semiconductor to accelerate hot electrons from plasmonic Au nanospheres for artificial photosynthesis and cross-coupling reactions

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-11, Vol.12 (46), p.3269-3283
• Main Authors: Kumar, Dinesh, Jaswal, Richa, Shrestha, Devendra, Kumar, Suresh, Park, Chan Hee, Kim, Cheol Sang
• Format: Article
• Language: English
• Subjects: Absorption; Carbon dioxide; Catalytic activity; Chemical reactions; Chemical synthesis; Cross coupling; Current carriers; Electromagnetic absorption; Electron density; Electrons; Energy charge; Energy gap; Heterostructures; Hot electrons; Light effects; N-type semiconductors; Nanoparticles; Nanospheres; Photocatalysis; Photochemical reactions; Photoreduction; Photosynthesis; Quantum efficiency; Shelf life; Thickness; Tin dioxide
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta03973d

Here, we report the synthesis of an n-type wide band gap semiconductor (SnO 2 ) and gold nanosphere (GNSs)-based core-satellite heterostructures (GNSs@SnO 2 ) composed of GNSs as core and ultra-small SnO 2 nanodots as a satellite with multiple thicknesses, which were then utilized for artificial photosynthesis and the Suzuki-Miyaura coupling reaction. SnO 2 nanodot coating thickness on GNSs was maintained as 3-4 nm (GNSs@SnO 2 -US), 6-7 nm (GNSs@SnO 2 -SS), and 14-15 nm (GNSs@SnO 2 -TS) and the prepared nanostructures were used for visible light-induced artificial photosynthesis and the Suzuki-Miyaura coupling reactions. The higher electron density in GNSs@SnO 2 -SS led to more light absorption, which generated high-energy hot charge carriers, resulting in a highly active photocatalyst for CO 2 conversion to HCOOH (quantum yield = 2.15%, chemical yield = 3.69%) with high selectivity (96%) and achieving a biphenyl yield of 99.15% in the cross-coupling of phenylboronic acid and iodobenzene. The apparent quantum efficiency for CO 2 photoreduction at 550 nm monochromatic wavelength was observed as 0.799%. GNSs@SnO 2 -SS showed robust structure and excellent colloidal stability with excellent reusability for at least 10 reaction cycles without losing catalytic activity and a high shelf life of 1 year. The prepared GNSs@SnO 2 -SS nanoparticles also displayed high photocatalytic activity in NIR and sunlight-induced CO 2 reduction and coupling reactions. The controlled coating of 6-7 nm SnO 2 nanodots on GNSs was found to be the optimized satellite thickness, which enhanced the electron density due to the wide band gap of SnO 2 . The increased electron density led to greater light absorption to generate high-energy hot electrons and hot holes. This led to high photocatalytic efficiency of GNSs@SnO 2 -SS for CO 2 reduction and cross-coupling reactions. Herein, an n-type wide band gap semiconductor (SnO 2 ) and gold nanosphere (GNSs)-based core-satellite heterostructures (GNSs@SnO 2 ) were prepared, and utilized for artificial photosynthesis and the Suzuki-Miyaura coupling reaction.