Gas-fed photoelectrochemical reactions sustained by phosphotungstic acid as an inorganic surface electrolyte†
Abstract
Gas-fed photoelectrochemical (PEC) system with a porous photoelectrode and proton-exchange membrane (PEM) has the potential to produce hydrogen from water vapour and activate methane at room temperature. To effectively drive gas-phase PEM-PEC reactions, porous photoelectrodes should be coated with a solid electrolyte of perfluorinated sulfonic acid (PFSA) ionomers. However, fluorocarbon-based ionomers were not chemically stable in vapour-fed PEC systems. Herein, we report that polyoxometalate, an inorganic proton-conducting material, may be employed as the surface electrolyte of a WO3 porous photoelectrode for vapour-fed water splitting and methane activation under visible light irradiation. We demonstrate that the porous WO3 photoanode modified with phosphotungstic acid (H3PW12O40) induces PEC reactions, including the oxygen evolution reaction and methane conversion, under gas feeding. Additionally, we demonstrated improved durability by using the inorganic surface electrolyte.
- This article is part of the themed collections: Research advancing UN SDG 13: Climate Action, Research advancing UN SDG 7: Affordable and clean energy, Research advancing UN SDG 12: Responsible consumption and production and Energy Advances: Highlight Japan & South Korea