Hybrid photocathode consisting of a CuGaO2 p-type semiconductor and a Ru(II)-Re(i) supramolecular photocatalyst: non-biased visible-light-driven CO2 reduction with water oxidation

Hiromu Kumagai, Go Sahara, Kazuhiko Maeda, Masanobu Higashi, Ryu Abe, Osamu Ishitani

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A CuGaO2 p-type semiconductor electrode was successfully employed for constructing a new hybrid photocathode with a Ru(II)–Re(I) supramolecular photocatalyst (RuRe/CuGaO2). The RuRe/CuGaO2 photocathode displayed photoelectrochemical activity for the conversion of CO2 to CO in an aqueous electrolyte solution with a positive onset potential of +0.3 V vs. Ag/AgCl, which is 0.4 V more positive in comparison to a previously reported hybrid photocathode that used a NiO electrode instead of CuGaO2. A photoelectrochemical cell comprising this RuRe/CuGaO2 photocathode and a CoOx/TaON photoanode enabled the visible-light-driven catalytic reduction of CO2 using water as a reductant to give CO and O2 without applying any external bias. This is the first self-driven photoelectrochemical cell constructed with the molecular photocatalyst to achieve the reduction of CO2 by only using visible light as the energy source and water as a reductant.
Original languageEnglish
Pages (from-to)4242-4249
Number of pages8
JournalChemical Science
Issue number6
Publication statusPublished - 1 Jan 2017
Externally publishedYes

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