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Photocatalysis & Astrobiology

web analyticsThe Guzman lab is investigating how to produce organic feedstock from the reduction of inorganic carbon through photocatalytic reductions. Basic project questions are: What organic products result from CO2 photoreduction over semiconductor supports? What is the time scale for effective electron transfer? What factors control the viability of the reactions in the reverse citric acid cycle on semiconductors? For example, the photocatalytic reduction of CO2 in water can mainly produce formate (HCOO) in the presence of ZnS semiconductor. By measuring reaction rates of formate production and the associated apparent quantum yield under continuous and periodic illumination we can report the time scale in which reducing electrons and oxidizing holes are transferred. We have also developed a method to determine the bandgap of a synthesized colloidal photocatalysts suspended in water by studying the dependence of the reaction rate on the wavelength of irradiation.

References:

Cu2O/TiO2 heterostructures for CO2 reduction through a direct Z-scheme: Protecting Cu2O from photocorrosion. M.E. Aguirre, R. Zhou, A.J. Eugene, M.I. Guzman, and M.A. Grela. Applied Catalysis B: Environmental (2017), 217, 485-493, DOI: 10.1016/j.apcatb.2017.05.058. PDF

Catalyzed Synthesis of Zinc Clays by Prebiotic Central Metabolites. R. Zhou, K. Basu, H. Hartman, C.J. Matocha, S.K. Sears, H. Vali, and M.I. Guzman. Scientific Reports (2017), 7, 533. DOI: 10.1038/s41598-017-00558-1. PDF

Photocatalytic Reduction of Fumarate to Succinate on ZnS Mineral Surfaces. R. Zhou and M.I. Guzman. Journal of Physical Chemistry C (2016), 120, 7349-7357. PDF

CO2 Reduction under Periodic Illumination of ZnS. R. Zhou and M.I Guzman. Journal of Physical Chemistry C (2014), 118, 11649-11656. PDF

Chemisorption on Semiconductors: the Role of Quantum Corrections on the Space Charge Regions in Multiple Dimensions. F. Ciucci, C. de Falco, M.I. Guzman, S. Lee, and T. Honda. Applied Physics Letters (2012), 100, 183106. PDF

Abiotic Photosynthesis: From Prebiotic Chemistry to Metabolism. M.I. Guzman in Origins of Life: The Primal Selforganization. R. Egel et al. (eds.), Springer Verlag, Berlin-Heidelberg (2011), pp 85-105, DOI 10.1007/978-3-642-21625-1_4, ISBN 978-3-642-21624-4.

From Prebiotic Chemistry to Metabolic Cycles. M.I. Guzman in Astrobiology: From the Big Bang to Civilizations.

Editors: G.A. Lemarchand and G.Tancredi (2010), pp. 223-247. ISBN 978-92-9089-163-5. Montevideo, UNESCO. PDF

Photo-Production of Lactate from Glyoxylate: How Minerals Can Facilitate Energy Storage in a Prebiotic World. M.I. Guzman and S.T. Martin. Chemical Communications (2010), 46, 2265-2267. PDF

Prebiotic Metabolism: Production by Mineral Photoelectrochemistry of α-Ketocarboxylic Acids in the Reductive Tricarboxylic Acid Cycle. M.I. Guzman and S.T. Martin. Astrobiology (2009), 9, 833-842. PDF

Synthesis of Pyrimidines and Triazines in Ice: Implications for the Prebiotic Chemistry of Nucleobases. C. Menor-Salván, M. Ruiz-Bermejo, M.I. Guzman, S. Osuna-Esteban, S. Veintemillas-Verdaguer. Chemistry-A European Journal (2009), 15, 4411-4418. PDF

Oxaloacetate-to-Malate Conversion by Mineral Photoelectrochemistry: Implications for the Viability of the Reductive Tricarboxylic Acid Cycle in Prebiotic Chemistry. M.I. Guzman and S.T. Martin. International Journal of Astrobiology (2008), 7, 271-278. PDF