MIL-100(Fe)/g-C(3)N(4) composites with enhanced photocatalytic activity for UO(2)(2+) reduction under visible light

Photocatalytic Hydrogen Peroxide Production by a Mixed Ligand-Functionalized Uranyl-Organic Framework

Hydrogen peroxide (H2O2) production driven by solar energy has received enormous attention due to its high efficiency, low cost, and environmental friendliness characteristics. Searching for new photocatalytic materials for H2O2 production is one of the most important targets. In this work, a new three-dimensional (3D) uranyl-organic framework material was constructed with mixed ligands via a solvothermal reaction and used for photocatalytic H2O2 production. The mixed ligand strategy not only benefits the construction of a 3D uranyl-organic framework but also introduces strong photon absorption groups into the framework. The thiophene and pyridine rings in the framework enhance photon absorption and carrier transfer. In addition, with the assistance of the hydrogen abstraction reaction of uranyl centers, the H2O2 production rate reaches 345 μmol h-1 g-1. This study provides a new blueprint for exploring the artificial photosynthesis of H2O2 through uranium-based metal-organic frameworks.

Solvent-regulated self-assembled carbon nitride for photocatalytic reduction of U(VI) in water

Manufacturing high-performance and reusable materials from radioactive uranium-containing wastewater remains a significant challenge. Herein, a supramolecular self-assembly strategy was proposed, using melamine and cyanuric acid as precursors and using intermolecular hydrogen bond force to form carbon nitride (CN-D) in different solvents through a single thermal polymerization strategy. Supramolecular self-assembly method is a promising strategy to synthesize a novel carbon nitride with molecular regulatory properties. In addition, 98% of U(VI) in wastewater can be removed by using CN-D for 60 min under visible light. After five cycles of recycling, more than 95% of U(VI) can still be reduced, indicating that it has good recyclability and reusability. This study not only provides an efficient photocatalytic method of uranium reduction, but also provides a new method for self-assembly synthesis.

Visible light-mediated synthesis of quinazolinones from benzyl bromides and 2-aminobenzamides without using any photocatalyst or additive

This paper reports a novel method for the visible-light-mediated synthesis of quinazolinones from the reaction of benzyl bromides with 2-aminobenzamides. The reaction proceeded efficiently at room temperature upon irradiation with an 18 W blue light-emitting diode in air without photocatalysts or additives. By varying the solvent type, substrate molar ratio, and reaction time, the optimal reaction conditions, including the use of methanol solvent, room temperature, and reaction time of 28 h, were identified. Under these conditions, various quinazolinones were obtained using 18 substrates, with the highest yield of 93%. To determine the industrial value of the proposed method, a scale-up reaction was performed and 80% product yield was achieved. Mechanistic studies revealed that the reaction likely proceeded via a radical pathway and that the hydrogen bromide by-product generated during the first step of the reaction of benzyl bromide with 2-aminobenzamide promoted the subsequent step.