title: Directed Assembly of Nanoparticle Catalysts on Nanowire Photoelectrodes for Photoelectrochemical CO2 Reduction.
abstract: Reducing carbon dioxide with a multicomponent artificial photosynthetic system, closely mimicking nature, represents a promising approach for energy storage. Previous works have focused on exploiting light-harvesting semiconductor nanowires (NW) for photoelectrochemical water splitting. With the newly developed CO2 reduction nanoparticle (NP) catalysts, direct interfacing of these nanocatalysts with NW light absorbers for photoelectrochemical reduction of CO2 becomes feasible. Here, we demonstrate a directed assembly of NP catalysts on vertical NW substrates for CO2-to-CO conversion under illumination. Guided by the one-dimensional geometry, well-dispersed assembly of Au3Cu NPs on the surface of Si NW arrays was achieved with facile coverage tunability. Such Au3Cu NP decorated Si NW arrays can readily serve as effective CO2 reduction photoelectrodes, exhibiting high CO2-to-CO selectivity close to 80% at -0.20 V vs RHE with suppressed hydrogen evolution. A reduction of 120 mV overpotential compared to the planar (PL) counterpart was observed resulting from the optimized spatial arrangement of NP catalysts on the high surface area NW arrays. In addition, this system showed consistent photoelectrochemical CO2 reduction capability up to 18 h. This simple photoelectrode assembly process will lead to further progress in artificial photosynthesis, by allowing the combination of developments in each subfield to create an efficient light-driven system generating carbon-based fuels.
authors: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors: Qiao
authors: Q
authors: Kong
authors: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
authors: Dohyung
authors: D
authors: Kim
authors: Department of Chemistry, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors: Chong
authors: C
authors: Liu
authors: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors: Yi
authors: Y
authors: Yu
authors: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors: Yude
authors: Y
authors: Su
authors: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors: Yifan
authors: Y
authors: Li
authors: Department of Chemistry, University of California , Berkeley, California 94720, United States.|Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy Nanosciences Institute , Berkeley, California 94720, United States.
authors: Peidong
authors: P
authors: Yang
keywords: artificial photosynthesis; carbon dioxide reduction; nanoparticle assembly; nanoparticle catalyst; nanowires