6533b82cfe1ef96bd128f6da

RESEARCH PRODUCT

Enhanced kinetics of hole transfer and electrocatalysis during photocatalytic oxygen evolution by cocatalyst tuning

Hai I. WangHai I. WangTatsuya ShinagawaEnrique CánovasSamy Ould-chikhTangui Le BahersZoltan MicsPhilippe SautetKazuhiro TakanabeMischa BonnSean FlanaganEla NurlaelaMuhammad Qureshi

subject

Materials scienceInorganic chemistryOxygen evolution02 engineering and technologyGeneral Chemistry[CHIM.CATA]Chemical Sciences/Catalysis010402 general chemistry021001 nanoscience & nanotechnologyElectrochemistryElectrocatalyst01 natural sciences7. Clean energyRedoxCatalysis0104 chemical sciencesCatalysisMetal[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry13. Climate actionvisual_artvisual_art.visual_art_mediumPhotocatalysis0210 nano-technologyCobalt oxideComputingMilieux_MISCELLANEOUS

description

Understanding photophysical and electrocatalytic processes during photocatalysis in a powder suspension system is crucial for developing efficient solar energy conversion systems. We report a substantial enhancement by a factor of 3 in photocatalytic efficiency for the oxygen evolution reaction (OER) by adding trace amounts (∼0.05 wt %) of noble metals (Rh and Ru) to a 2 wt % cobalt oxide modified Ta3N5 photocatalyst particulate. The optimized system exhibited high quantum efficiencies (QEs) of up to 28 and 8.4% at 500 and 600 nm in 0.1 M Na2S2O8 at pH 14. By isolation of the electrochemical components to generate doped cobalt oxide electrodes, the electrocatalytic activity of cobalt oxide on doping with Ru or Rh was improved in comparison with cobalt oxide, as evidenced by the onset shift for electrochemical OER. Density functional theory (DFT) calculations show that the effect of a second metal addition is to perturb the electronic structure and redox properties in such a way that both hole transfer kin...

10.1021/acscatal.6b00508https://hal.archives-ouvertes.fr/hal-01531511