A novel photoelectrochemical flow cell with online mass spectrometric detection: oxidation of formic acid on a nanocrystalline TiO2 electrode

Abstract

A novel thin-layer photoelectrochemical flow cell allowing the online mass spectrometric detection of volatile reaction products during photoelectrocatalytic reactions has been developed and applied for separating the contributions from photoelectrochemical water splitting and photoelectrooxidation of formic acid to the overall photocurrent in formic acid containing aqueous solution, using a nanocrystalline TiO₂ (P25) thin-film electrode. The data reveal a clear suppression of the water oxidation reaction to O₂ in the presence of formic acid. Advantages of this flow cell design over conventional photoelectrochemical cells with stagnant electrolyte in terms of mass transport will be demonstrated and discussed.