From sunlight to valuable molecules: A journey through photocatalytic and photoelectrochemical glycerol oxidation towards valuable chemical products

Photocatalysis holds the tantalizing potential to satisfy global energy demand, reduce greenhouse effect, and resolve environmental contamination. In particular, chemical transformation of biomass by sunlight has delivered a sustainable and decarbonized approach to the production of chemicals and fuels by using the abundant resources on earth. As the major byproduct in biodiesel processing, glycerol has introduced itself as a renewable, bio-derived feedstock for the production of value-added chemicals. To this end, the development of sunlight-driven "glycerochemistry" capable of transforming glycerol into high value-added chemicals has received much research attention over recent years. This Review summarizes the recent progress achieved in the realization of value-added chemical production from photocatalytic (PC) and photoelectrochmeical (PEC) glycerol oxidation. Spotlights are shined on the design of critical photoactive materials and the devising of reliable strategies that enable a rational control over the selectivity toward a desired product. Additionally, it addresses the current gaps in the interpretation of a veritable reaction mechanism both experimentally and theoretically. Lastly, current challenges and future prospects are pinpointed in order to accelerate the widespread deployment of PC and PEC glycerol valorization in academia and industries.