Simultaneous Degradation\nof Organic Pollutants and\nHydrogen Production Using Dual-Functional NH<sub>2</sub>‑MIL-125(Ti)/Red\nPhosphorus Heterostructure under Solar Light Irradiation

Herein, NH<sub>2</sub>-MIL-125(Ti)/red phosphorus heterostructures\nwith varying weight percentages of NH<sub>2</sub>-MIL-125(Ti) (NMT)\nmetal–organic framework (MOF) were prepared by using a solvothermal\nmethod. The morphological and structural characterization results\nof the heterostructures depicted strong surface interactions between\nred phosphorus (RP) and NMT MOF. The photoluminescence and electrochemical\nimpedance spectroscopy studies exhibited improved charge transfer\nproperties of the heterostructures compared to those of RP and NMT\nMOF. The prepared NMT/red phosphorus heterostructures were tested\nfor the simultaneous photocatalytic degradation of organic pollutants\n(2,4-dinitrophenol, 4-nitrophenol, 2,4,6-trinitrophenol, rhodamine\nB, methylene blue, and rhodamine 6G) and hydrogen production. The\nincreased separation of charge carriers of the 5% NMT/red phosphorus\ncatalyst over the formed Z-scheme heterojunction led to the achievement\nof the best activity for the simultaneous process. A maximum H<sub>2</sub> production rate (517.97 μmol h<sup>–1</sup> g<sup>–1</sup>) was observed in the rhodamine B dye solution, which\nwas much higher than that in the pure water system (39.76 μmol\nh<sup>–1</sup> g<sup>–1</sup>). This was because, among\nall of the organic pollutants, rhodamine B dye acted as the best hole\nscavenger, thus leaving the maximum available photogenerated electrons\nfor H<sub>2</sub> production. Furthermore, optimum degradation efficiency\n(97.8%) was achieved for methylene blue dye. Moreover, during four\ncycles of reusability, the photocatalyst showed outstanding H<sub>2</sub> production and degradation stability, making it suitable\nfor use in practical solutions for water and energy issues. Therefore,\nthis work allows for the simultaneous mitigation of wastewater treatment\nand energy scarcity issues by developing an effective method to prepare\nZ-scheme heterostructured catalysts with favorable band structures\nand optimum activity.