How Light-Harvesting Semiconductors Can Alter the Bias of Reversible Electrocatalysts in Favor of H2 Production and CO2 Reduction

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• 作者：Andreas Bachmeier ; Vincent C. C. Wang ; Thomas W. Woolerton ; Sophie Bell ; Juan C. Fontecilla-Camps ; Mehmet Can ; Stephen W. Ragsdale ; Yatendra S. Chaudhary ; Fraser A. Armstrong
• 刊名：Journal of the American Chemical Society
• 出版年：2013
• 出版时间：October 9, 2013
• 年：2013
• 卷：135
• 期：40
• 页码：15026-15032
• 全文大小：441K
• 年卷期：v.135,no.40(October 9, 2013)
• ISSN：1520-5126

文摘

The most efficient catalysts for solar fuel production should operate close to reversible potentials, yet possess a bias for the fuel-forming direction. Protein film electrochemical studies of Ni-containing carbon monoxide dehydrogenase and [NiFeSe]-hydrogenase, each a reversible electrocatalyst, show that the electronic state of the electrode strongly biases the direction of electrocatalysis of CO₂/CO and H⁺/H₂ interconversions. Attached to graphite electrodes, these enzymes show high activities for both oxidation and reduction, but there is a marked shift in bias, in favor of CO₂ or H⁺ reduction, when the respective enzymes are attached instead to n-type semiconductor electrodes constructed from CdS and TiO₂ nanoparticles. This catalytic rectification effect can arise for a reversible electrocatalyst attached to a semiconductor electrode if the electrode transforms between semiconductor- and metallic-like behavior across the same narrow potential range (<0.25 V) that the electrocatalytic current switches between oxidation and reduction.