Photocatalysis and electrolysis are crucial processes for the development of a sustainable, clean energy system, since they enable solar fuel production, such as hydrogen by water splitting, as well as CO2 reduction [1,2]. In these processes efficient and robust catalysts for water oxidation are required and the reduction of employed amount of noble metals is crucial to reduce costs and increase the sustainability of the technology. We have employed electroless deposition by spontaneous galvanic displacement [1–4] as a simple, low cost, highly scalable technique. By varying the deposition parameters, optimal conditions for Pt and IrO2 deposition on Nickel foam have been achieved [5–7]. The electrode coverage by catalyst has also a positive impact on its stability, strongly decreasing the degradation rate, compared to the case of bare Ni foam. The average amount of noble metal in the best performing electrodes is well below the typical values adopted for PEM (Proton Exchange Membranes Electrolyzers) [8]. The proposed approach is highly promising for gas diffusion electrodes, and can be implemented in electrolytic cells, as well as in fuel cells.
References
[1] Milazzo RG, Mio AM, D’Arrigo G, Spinella C, Grimaldi MG, Rimini E. Electroless deposition of gold investigated with rutherford backscattering and electron microscopy. 2014 IEEE 9th Nanotechnology Materials and Devices Conference (NMDC) 2014:37–40. https://doi.org/10.1109/NMDC.2014.6997416.
[2] Milazzo RG, Privitera S, Litrico G, Scalese S, Mirabella S, La Via F, et al. Formation, Morphology, and Optical Properties of Electroless Deposited Gold Nanoparticles on 3C-SiC. Journal of Physical Chemistry C 2017;121. https://doi.org/10.1021/acs.jpcc.6b11638.
[3] Milazzo RG, Mio AM, D’Arrigo G, Grimaldi MG, Spinella C, Rimini E. Coalescence of silver clusters by immersion in diluted HF solution. The Journal of Chemical Physics 2015;143:024306. https://doi.org/10.1063/1.4926530.
[4] Milazzo RG, Privitera SMS, Scalese S, Mirabella S, Bongiorno C, Lombardo SA, et al. New insight into Pt nucleation mechanism on Si surface during galvanic displacement deposition. Journal of Physics and Chemistry of Solids 2021;148:109722. https://doi.org/10.1016/j.jpcs.2020.109722.
[5] Milazzo RG, Privitera SMS, Scalese S, Monforte F, Bongiorno C, Condorelli GG, et al. Ultralow loading electroless deposition of IrOx on nickel foam for efficient and stable water oxidation catalysis. International Journal of Hydrogen Energy 2020;45:26583–94. https://doi.org/10.1016/j.ijhydene.2020.07.049.
[6] Milazzo RG, Privitera SMS, Scalese S, Lombardo SA. Effect of morphology and mechanical stability of nanometric platinum layer on nickel foam for hydrogen evolution reaction. Energies 2019;12. https://doi.org/10.3390/en12163116.
[7] Milazzo RG, Privitera SMS, D’Angelo D, Scalese S, Di Franco S, Maita F, et al. Spontaneous galvanic displacement of Pt nanostructures on nickel foam: Synthesis, characterization and use for hydrogen evolution reaction. International Journal of Hydrogen Energy 2018:7903–10. https://doi.org/10.1016/j.ijhydene.2018.03.042.
[8] Jia J, Seitz LC, Benck JD, Huo Y, Chen Y, Ng JWD, et al. Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30%. Nature Communications 2016;7. https://doi.org/10.1038/ncomms13237.
