Issue 9, 2018

Proton coupled electron transfer from Co3O4 nanoparticles to photogenerated Ru(bpy)33+: base catalysis and buffer effect

Abstract

Co3O4 nanoparticles in the spinel crystalline structure are among the most promising catalysts for the water oxidation reaction, displaying remarkable activity under electrochemical and light-assisted conditions. In the presence of Ru(bpy)32+ as a photosensitizer (bpy = 2,2′-bipyridine) and Na2S2O8 as an electron acceptor, 5 ± 1 nm size Co3O4 nanoparticles show a slow primary electron transfer (ET) to photogenerated Ru(III), occurring in a timescale of tens of milliseconds. We demonstrate herein that (i) photo-oxidation of Co3O4 NPs by Ru(III) involves transformation of surface Co(III)–OH sites to formal Co(IV)[double bond, length as m-dash]O, along a proton-coupled electron-transfer (PCET) pathway; (ii) the rate of the process depends on pH, and on the nature and concentration of the buffer; (iii) borate promotes general base catalysis of the PCET; and (iv) inhibition of the PCET is observed at high buffer concentration, due to H3BO3 poisoning of the surface Co sites, resulting in depletion of the O2 evolution activity.

Graphical abstract: Proton coupled electron transfer from Co3O4 nanoparticles to photogenerated Ru(bpy)33+: base catalysis and buffer effect

Supplementary files

Article information

Article type
Communication
Submitted
12 Jun 2018
Accepted
24 Jul 2018
First published
25 Jul 2018

Sustainable Energy Fuels, 2018,2, 1951-1956

Proton coupled electron transfer from Co3O4 nanoparticles to photogenerated Ru(bpy)33+: base catalysis and buffer effect

G. A. Volpato, A. Bonetto, A. Marcomini, P. Mialane, M. Bonchio, M. Natali and A. Sartorel, Sustainable Energy Fuels, 2018, 2, 1951 DOI: 10.1039/C8SE00275D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements