Towards Photoelectrochemical Disinfection of Water: Generation of Strong Oxidants Using WO3 Photoanode

Towards Photoelectrochemical Disinfection of Water: Generation of Strong Oxidants Using WO₃ Photoanode

J. Juodkazytė, M. Petrulevičienė, I. Savickaja, M. Parvin

Center for Physical Sciences and Technology, Saulėtekio av. 3, LT-10257, Vilnius

Sustainable production of hydrogen via photoelectrochemical (PEC) splitting of water is among the most intensively investigated processes in the area of artificial photosynthesis. The benefit of solar water splitting can be increased by coupling generation of H₂ on cathode with production of high added-value chemicals, e.g. HClO, H₂O₂, H₂S₂O₈, etc. on photoanode [1]. Photoinduced synthesis of strong oxidants is gaining its place amongst the advanced oxidation processes, which are especially suitable for water disinfection and purification. Our research has been focused on PEC generation of reactive chlorine species (RCS) (ClO^- + ClO₂^-) and S₂O₈^2- using WO₃ photoanodes [2-4] in chloride and sulfate electrolytes. Faradaic efficiencies close to 100 % for RCS and 80 % for persulfate were found. Applicability of the system for inactivation of bacteria was demonstrated. Factors determining the stability of WO₃ films during photoelectrolysis along with possible reaction pathways will be discussed.

Literature:

[1] K. Sayama, ACS Energy Lett. 2018, 3, 1093.

[2] J. Juodkazytė, J. Electroanal. Chem. 2020, 871, 114277.

[3] M. Parvin, Electrochim. Acta 2022, 403, 139710.                 

[4] M. Petrulevičienė, J. Solid State Electrochem. 2022, 26, 1021.

Acknowledgement:

This research was funded by the M-ERA.NET project “Multiscale computer modelling, synthesis and rational design of photo(electro)catalysts for efficient visible-light-driven seawater splitting”(CatWatSplit), Reference Number: project8168, under a grant agreement Nr. S-M-ERA.NET-21-3 with the Research Council of Lithuania (LMTLT).