Design-controlled synthesis of IrO2 sub-monolayers on Au nanoflowers: marrying plasmonic and electrocatalytic properties

Author(s):Show less -

de Freitas, Isabel C. ^[1] ; Parreira, Luanna S. ^[1] ; Barbosa, Eduardo C. M. ^[1] ; Novaes, Barbara A. ^[1] ; Mou, Tong ^{[2, 3]} ; Alves, Tiago. V. ^[4] ; Quiroz, Jhon ^[5] ; Wang, Yi-Chi ^[6] ; Slater, Thomas J. ^{[6, 7]} ; Thomas, Andrew ^[6] ; Wang, Bin ^{[2, 3]} ; Haigh, Sarah J. ^[6] ; Camargo, Pedro H. C. ^{[1, 5]}

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Oklahoma, Gallogly Coll Engn, Ctr Interfacial React Engn, Norman, OK 73019 - USA

^[3] Univ Oklahoma, Gallogly Coll Engn, Sch Chem Biol & Mat Engn, Norman, OK 73019 - USA

^[4] Univ Fed Bahia, Inst Quim, Dept Fis Quim, Rua Barao de Jeremoabo 147, BR-40170115 Salvador, BA - Brazil

^[5] Univ Helsinki, Dept Chem, AI Virtasen Aukio 1, Helsinki - Finland

^[6] Univ Manchester, Sch Mat, Manchester M13 9PL, Lancs - England

^[7] Diamond Light Source Ltd, Electron Phys Sci Imaging Ctr, Didcot OX11 0DE, Oxon - England

• Document type: Journal article
• Source: NANOSCALE; v. 12, n. 23, p. 12281-12291, JUN 21 2020.
• Web of Science Citations: 0

Abstract

We develop herein plasmonic-catalytic Au-IrO2 nanostructures with a morphology optimized for efficient light harvesting and catalytic surface area; the nanoparticles have a nanoflower morphology, with closely spaced Au branches all partially covered by an ultrathin (1 nm) IrO2 shell. This nanoparticle architecture optimizes optical features due to the interactions of closely spaced plasmonic branches forming electromagnetic hot spots, and the ultra-thin IrO2 layer maximizes efficient use of this expensive catalyst. This concept was evaluated towards the enhancement of the electrocatalytic performances towards the oxygen evolution reaction (OER) as a model transformation. The OER can play a central role in meeting future energy demands but the performance of conventional electrocatalysts in this reaction is limited by the sluggish OER kinetics. We demonstrate an improvement of the OER performance for one of the most active OER catalysts, IrO2, by harvesting plasmonic effects from visible light illumination in multimetallic nanoparticles. We find that the OER activity for the Au-IrO2 nanoflowers can be improved under LSPR excitation, matching best properties reported in the literature. Our simulations and electrocatalytic data demonstrate that the enhancement in OER activities can be attributed to an electronic interaction between Au and IrO2 and to the activation of Ir-O bonds by LSPR excited hot holes, leading to a change in the reaction mechanism (rate-determinant step) under visible light illumination. (AU)

• FAPESP's process: 16/17866-9 - Tailoring the catalytic properties of plasmonic Nanorattles towards the photochemical activation of oxygen under mild conditions
• Grantee: Jhon Jhon Quiroz Torres
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
• Grantee: Roberto Manuel Torresi
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 16/00819-8 - Controlled Synthesis of Nanomaterials based on Pd and Pt: Electrocatalytic Activity and Stability
• Grantee: Luanna Silveira Parreira
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 15/11452-5 - Hybrid materials composed of oxides and metallic nanoparticles for catalytic and photocatalytic applications
• Grantee: Eduardo César Melo Barbosa
• Support type: Scholarships in Brazil - Doctorate (Direct)