Coproduction of Hydrogen and Value-Added Chemicals Using Ni-TiO ₂ @g-C ₃ N ₄ Nanocomposites from Glycerol Photoreforming

Photocatalytic hydrogen production is an alternative strategy that can be used to attain sustainable solar energy conversion and storage. Regarding the solar-to-hydrogen process, photocatalytic hydrogen generation in the presence of a sacrificial agent has become a viable approach. However, the nonselective oxidation of sacrificial agents is responsible for the higher cost of green hydrogen production. Hence, this work presents the strategic design of a bifunctional photocatalyst that can simultaneously generate value-added chemicals and produce hydrogen from glycerol. The glycerol photoreforming process was realized on the well-fabricated Ni-TiO2@g-C3N4 composite photocatalysts. The combination of Ni-TiO2 and g-C3N4 not only enhanced the separation efficiency of photogenerated electrons and holes but also extended the light absorption from the ultraviolet region to the visible region. These significant promotions contributed to photocatalytic hydrogen production from glycerol while valuable chemicals of glyceraldehyde, dihydroxyacetone, and glycolic acid were selectively produced at the same time. As a result, the maximum hydrogen generation and glycerol conversion were achieved with rates of approximately 32,000 μmolg–1h–1 and 73%, respectively, on the optimized Ni-TiO2@g-C3N4 composite. This present work provides an important example for the coproduction of value-added compounds and sustainable hydrogen by the rational design of bifunctional photocatalysts.