Photoelectrochemical conversion of glycerol aqueous solution to value-added chemicals using Bi₂Fe₄O₉ as a photoanode

A low-cost, stable and non-toxic Bi2Fe4O9 (BFO) photoanode was used for the first time to promote glycerol aqueous solution photoelectrochemical conversion to hydrogen and value-added chemicals. Photoelectrochemical measurements were performed under AM1.5G irradiation using a three-electrode cell. The best performance was achieved in alkaline medium, where four distinct glycerol oxidation products were detected (glycerate, formate, glycolate and lactate). In neutral medium, no oxidation products were detected. In acidic medium, we observed an improved selectivity, with only glyceraldehyde and dihydroxyacetone as oxidation products. Our results show that the electron-hole recombination, which restricts the efficiency of glycerol conversion, is one of the main shortcomings of BFO. However, its high open circuit potential (OCP) value and several other desirable properties for a good photoelectrocatalyst make it a material worth further research.