Hollow NiP–ZnIn2S4 Heterojunction for Simultaneous Hydrogen and Pyruvic Acid Production from Lactic Acid Photoreforming

Photocatalytic hydrogen production provides an alternative approach to sustainable energy storage and conversion. However, the nonselective oxidation of sacrificial agents greatly increases the cost of green hydrogen generation. Herein, we demonstrate the simultaneous production of hydrogen and value-added chemicals by rationally designing a bifunctional photocatalyst. This approach uses hollow ZnIn2S4 spheres with NiP as a cocatalyst, which enables the photocatalyst with dual functionalities to produce sustainable hydrogen and selectively dehydrogenate lactic acid into pyruvic acid. As a result, 381 μmol/h of H2 is produced on the optimized photocatalyst with an apparent quantum yield of 11.1% at 365 ± 20 nm monochromatic light. Meanwhile, pyruvic acid, with a selectivity of 97.8%, is simultaneously achieved from lactic acid oxidation. Techno-economic analysis reveals the profitability of the present system and provides a promising outlook for the sustainability and economic viability of the unit. The present work demonstrates a good example of sustainable hydrogen and valuable chemical coproduction with the rational design of bifunctional photocatalytic materials.