In Situ Growth of NiFe‐LDH/ZIF‐7 Composite With Boosted Photocatalytic Efficiency for Methyl Orange Removal

ABSTRACT Fabricating cost‐effective and efficient photocatalytic materials for the degradation of organic pollutants is a significant challenge due to the intrinsic limitations of conventional photocatalysts. The present work describes a nanoporous NiFe layered double hydroxide/ZIF‐7 (NiFe‐LDH/ZIF‐7) heterojunction photocatalyst that was successfully synthesized using a facile in‐situ two‐step hydrothermal method, to offer a promising solution to these limitations. The synthesis and the incorporation of NiFe‐LDH to the ZIF‐7 framework were affirmed by comprehensive structural and morphological characterizations, x‐ray diffraction (XRD), scanning electron microscopy (SEM), UV‐visible spectroscopy, and Fourier‐transform infrared spectroscopy (FTIR). The photocatalytic activity of the NiFe‐LDH/ZIF‐7 composite was appraised with methyl orange (MO) dye degradation as a test pollutant at exposure to natural sunlight radiation. The synthesized composite provided a remarkable degradation performance of 93.9% in 100 min with the pseuodo‐first‐order rate constant of 0.03 min −1 , which was much better than pristine ZIF‐7. NiFe‐LDH/ZIF‐7 showed excellent reusability with 85.3% efficiency after four cycles, and trapping experiments revealed superoxide radicals as the dominant species. The synergistic effect between NiFe‐LDH and ZIF‐7 components is related to the enhanced activity because it offers an effective photogenerated charge separation and creates a path for reactive species. This work not only reports high photocatalytic activities of NiFe‐LDH/ZIF‐7, but also provides a stimulus to the design of high‐performance photocatalysts that have a high surface area to treat the wastewater.