Photocatalytic liquid-phase selective hydrogenation of furfural to furfuryl alcohol without external hydrogen on graphene-modified TiO2 with different polymorphs

The photocatalytic selective hydrogenation of furfural to furfuryl alcohol (FA) on various TiO2, including pure anatase TiO2, mixed anatase/rutile P25, and sol-gel-TiO2, is significantly enhanced by the addition of graphene. Incorporating 10 wt.% graphene sheets onto P25 resulted in a 60% increase in FA yield. XPS, UV–Vis, and PL spectroscopy results suggest the formation of Ti–O–C bonds and the generation of Ti3+ species, which facilitate electron transfer from the conduction bands to the conductive graphene, thereby improving the photocatalytic activity. However, increasing the graphene loading to 15 wt.% may instead lead to decreased charge separation efficiency in the photocatalysts.