Making mesoporous rhodium (Rh) with traditional soft-templating methods is challenging because Rh has a high surface energy compared to other metals. Here, we report a synthetic concept to generate mesoporous Rh films (MRFs) by electrochemical co-deposition of Rh precursors and block copolymer micelles. We investigate the effect of deposition potentials and pH on the resulting mesoporous structures. Controlled electrodeposition enables us to conformally coat the entire surface of the electrode with a homogeneous mesoporous Rh film with any arbitrary thickness up to ∼840 nm. The average pore size of the MRF is ∼14 nm, with an average wall thickness of ∼9.5 nm. Since the MRFs are directly deposited on conducting substrates, they can be used as porous electrodes for various important electrocatalytic reactions. We examine the performance of these MRFs for the electrochemical methanol oxidation reaction (MOR) and find that they have a mass-normalized peak current density ∼4 times higher than a commercial Rh black (RhB) catalyst.
Bibliographical noteFunding Information:
This work was supported by the Australian Research Council (ARC) Future Fellow (grant FT150100479). This work was performed in part at the Queensland node of the Australian National Fabrication Facility, a company established under the National Collaborative Research Infrastructure Strategy to provide nano-and micro-fabrication facilities for Australia’s researchers.
© 2019 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Materials Science(all)