Final report : CO2 reduction using biomimetic photocatalytic nanodevices.

Technical Report · Sun Nov 01 00:00:00 EDT 2009

DOI:https://doi.org/10.2172/973339· OSTI ID:973339

Garcia, Robert M; Shelnutt, John Allen; Medforth, Craig John ^[1]; Song, Yujiang; Wang, Zhongchun; Miller, James Edward; Wang, Haorong

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1. University of New Mexico Albuquerque, NM

Nobel Prize winner Richard Smalley was an avid champion for the cause of energy research. Calling it 'the single most important problem facing humanity today,' Smalley promoted the development of nanotechnology as a means to harness solar energy. Using nanotechnology to create solar fuels (i.e., fuels created from sunlight, CO{sub 2}, and water) is an especially intriguing idea, as it impacts not only energy production and storage, but also climate change. Solar irradiation is the only sustainable energy source of a magnitude sufficient to meet projections for global energy demand. Biofuels meet the definition of a solar fuel. Unfortunately, the efficiency of photosynthesis will need to be improved by an estimated factor of ten before biofuels can fully replace fossil fuels. Additionally, biological organisms produce an array of hydrocarbon products requiring further processing before they are usable for most applications. Alternately, 'bio-inspired' nanostructured photocatalytic devices that efficiently harvest sunlight and use that energy to reduce CO{sub 2} into a single useful product or chemical intermediate can be envisioned. Of course, producing such a device is very challenging as it must be robust and multifunctional, i.e. capable of promoting and coupling the multi-electron, multi-photon water oxidation and CO{sub 2} reduction processes. Herein, we summarize some of the recent and most significant work towards creating light harvesting nanodevices that reduce CO{sub 2} to CO (a key chemical intermediate) that are based on key functionalities inspired by nature. We report the growth of Co(III)TPPCl nanofibers (20-100 nm in diameter) on gas diffusion layers via an evaporation induced self-assembly (EISA) method. Remarkably, as-fabricated electrodes demonstrate light-enhanced activity for CO{sub 2} reduction to CO as evidenced by cyclic voltammograms and electrolysis with/without light irradiation. To the best of our knowledge, it is the first time to observe such a light-enhanced CO{sub 2} reduction reaction based on nanostructured cobalt(III) porphyrin catalysts. Additionally, gas chromatography (GC) verifies that light irradiation can improve CO production by up to 31.3% during 2 hours of electrolysis. In addition, a variety of novel porphyrin nano- or micro-structures were also prepared including nanospheres, nanotubes, and micro-crosses.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 973339
• Report Number(s): SAND2009-7802; TRN: US201006%%726
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
29 ENERGY PLANNING
POLICY AND ECONOMY
BIOFUELS
CATALYSTS
CLIMATES
DIFFUSION
ELECTRODES
ELECTROLYSIS
ENERGY DEMAND
ENERGY SOURCES
EVAPORATION
FOSSIL FUELS
GAS CHROMATOGRAPHY
HARVESTING
HYDROCARBONS
IRRADIATION
NANOTUBES
OXIDATION
PHOTOSYNTHESIS
PORPHYRINS
SOLAR ENERGY
STORAGE
Solar energy.
Nanotechnology.