Long-Term Selective Photoelectrochemical Glycerol Oxidation via Oxygen Vacancy Modulated Tungsten Oxide with Self-Healing

Abstract

The photoelectrochemical selective oxidation of biowaste glycerol into the high value-added material, along with hydrogen production, holds significant promise for advancing renewable and sustainable energy technologies. Here, the surface oxygen state of tungsten oxide is modified to selectively oxidize glycerol into glyceraldehyde, a high-value-added material, and the selectivity is maintained over a prolonged period using the photo-stimulated self-recovery capability. The surface-coordinated photoelectrode exhibits high charge transfer efficiency to glycerol and favorable glycerol adsorption capacity, enabling the selective conversion of glycerol. At 1.2 VRHE in a 2 m glycerol electrolyte adjusted to pH 2, the tungsten oxide photoelectrode achieves a photocurrent density of 2.58 mA cm−2 and a production rate of 378.8 mmol m−2 h−1 with selectivity of 86.1%. The high selectivity is preserved for 18 h by utilizing the self-healing capability of tungsten oxide to restore initial states modified by photoelectrochemical oxidation. This work sheds light on the design of highly efficient metal oxide photoelectrodes for selective biomass oxidation over extended periods.