Solar-light-driven photocatalytic conversion of monosaccharide by oxygen-doped graphitic carbon nitride/artificial steel converter slag composite

The development of high performance, low-cost and resource-efficient photocatalysts with improved solar light harvesting capabilities can significantly enhance the practicability and viability of photocatalytic conversion of biomass-based substances to value-added chemicals. This work reports the construction of heterojunction between oxygen-doped graphitic carbon nitride and artificial steel converter slag (OCN/artCS) as efficient photocatalysts for conversion of biomass-derived monosaccharide to lactic acid under the simulated solar light. The OCN/artCS composites were facilely fabricated by the thermal polymerization of the mixtures of dicyanamide (DA) and oxalic acid (OA), which are precursors of OCN. The artCS acts as photocatalyst support for OCN to grow on its surface and can provide Ca2Fe2O5 semiconductor to possibly form the OCN/Ca2Fe2O5-containing artCS heterojunction. Compared with pristine OCN, the OCN/artCS composites exhibited higher photocatalytic performance for selective production of lactic acid, possibly due to the effective separation of photogenerated charge carriers after creation of OCN/artCS heterojunction. At the optimal content of artCS in the composites, the OCN/5%artCS delivered 99% glucose conversion and 90% lactic acid yield within 60 min at 50 °C under the simulated sunlight irradiation. This work can be a platform for the efficient utilization of industrial solid wastes for production of high-performance photocatalysts, enabling their promising applications in photobiorefinery and other photocatalytic processes.