Good dispersibility of graphene in a medium or matrix is a critical issue in practical applications. In this work, graphene was functionalized using N-(4-hydroxyl phenyl) maleimide (4-HPM) via the Diels—Alder (DA) reaction by a one-step catalyst-free approach. The optimal reaction condition was found to be 90 °C for 12 h using dimethylformamide (DMF) as the solvent. FTIR, Raman spectroscopy, XPS and EDS proved that 4-HPM moieties were successfully grafted onto the surface of graphene. UV-vis and TGA confirmed that the grafting amount of 4-HPM was 3.75%–3.97% based on the mass of graphene. Functionalized graphene showed excellent dispersion stability when dispersed in common solvents such as ethanol, DMF, water, tetrahydrofuran and p-xylene. Meanwhile, functionalized graphene also exhibited pH sensitivity in aqueous due to the phenolic hydroxyls from the 4-HPM moieties. As a result of good dispersion stability and pH sensitivity, compared with graphene, functionalized graphene had better adsorption capacity for methylene blue (MB) from aqueous solution.
Efficient aromatic alcohol oxidation with simultaneous H 2 evolution under aqueous conditions is achieved in a polyoxometalate (POM)-incorporated ZnIn 2 S 4 dual-functional photocatalytic system. The synergy between HPM and ZIS contributes to the formation of a Z-type heterojunction structure and thus enhances redox capacity. Moreover, the sub-nanometer size of POM clusters endows molecular-level interfacial contact, which acts as an "electron bridge" ensuring faster interfacial charge transfer kinetics. Therefore, an impressive nearly 100% yield of benzaldehyde and 10.6 mmol·g −1 ·h −1 H 2 -evolution rate are observed for POM/ZIS nanocomposites even under an anaerobic atmosphere with water as the solvent. This is the first application of POM-based materials in the anaerobic oxidation of benzyl alcohol with concomitant H 2 production. This study expands the possibilities for designing multifunctional POM-based photocatalysts for economic and ecological photoredox applications.
危险品化学品经营许可证（带存储）