Electrospinning Polymethyl Methacrylate (PMMA)/UiO-66 for Hydrogen Generation via NaBH4 Hydrolysis

Abstract

Metal–organic framework (MOF) using UiO-66 as a model was fabricated into nanofibers via electrospinning with poly(methyl methacrylate) (PMMA), denoted as PUiO-66. The materials, containing different Ui-O66 loadings, were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), diffuse reflectance spectroscopy (DRS), and Tauc plots. Electrospun PUiO-66 exhibits a nanostructure with nanofiber diameters in the 150–400-nm range. UiO-66-derived polymer nanofibers (PUiO-66) were reported for hydrogen production via the photocatalytic hydrolysis of sodium borohydride (NaBH₄). UiO-66 was integrated into electrospun PMMA fibers at varying loadings (0.2%, 0.5%, and 1.0%). The shape and homogeneity of the fibers were evaluated via SEM, while their optical properties were studied through DRS and Tauc plots, indicating a decrease in optical bandgap with high UiO-66 loading. The PUiO-66 (1%) demonstrated the maximum catalytic activity, attaining a hydrogen generating rate (HGR) of 500 mL/g·min, about five times higher than that of the PUiO-66 (0.2%). The photocatalytic activity significantly decreased the reaction time, demonstrating the effect of UV absorption of the PUiO-66 fibers on NaBH₄ hydrolysis. The influence of NaBH₄ concentration on hydrogen production was examined, revealing that increased reactant loading markedly enhanced the reaction rate and decreased time for the hydrolysis. The photocatalytic performance of the fibers can be recycled for five successive cycles without a significant drop in the material's performance. Our findings reveals the promising of PUiO-66 nanofibers for effective hydrogen production via photocatalytic hydrolysis of NaBH₄.