Novel MoS2-3,4,9,10-perylene tetracarboxylic acid heterojunction for efficient solar-driven photocatalytic reduction of Cr(VI)

Solar-driven photocatalysis is a promising green technology for wastewater treatment. Molybdenum disulfide (MoS 2 ) is a highly efficient visible-light photocatalyst. However, due to the rapid recombination of photoinduced electron-hole (e - -h + ) pairs, its photocatalytic activity is severely limited, thereby hindering its practical application. To solve this problem, a novel MoS 2 -3,4,9,10-perylene tetracarboxylic acid (MoS 2 -PTCDG) heterojunction was synthesized via a hydrothermal method. In this composite, PTCDG nanosheets are embedded in the interlayer spaces of three-dimensional flower-like MoS 2 nanospheres, forming an organic–inorganic heterostructure. This design not only improves the separation efficiency of photogenerated e - -h + pairs, but also the hydrophilic terminal carboxyl groups on PTCDG can serve as adsorption sites for Cr(VI) pollutants. The MoS 2 -PTCDG composite demonstrates exceptional photocatalytic activity and stability in degrading Cr(VI) under simulated sunlight, achieving a reaction rate constant 2.5 times higher than that of pure MoS 2 . This study highlights the potential of rationally designed organic–inorganic heterostructures to overcome the limitations of traditional MoS 2 -based photocatalysts, thus offering new insights into the development of high-performance photocatalytic materials for environmental remediation.