“…However, although 3-HBL and its hydrolyzed form 3,4-dihydroxybutyric acid (3,4-DHBA) have been reported to be produced from biomass (glucose, glycolic acid, and xylose) via biological synthesis using bacteria (Escherichia coli), enzymes and yeast, its production via a photocatalytic process has not yet been realized. [110][111][112] Future efforts would combine photocatalysts with microbes to create abiotic-biotic hybrids capable of producing photocatalytic H 2 while oxidizing biomass to 3-HBL. Likewise, the H 2 production costs can be reduced by photocatalytic transformations to produce value-added organic and inorganic chemicals.…”