Catalytic activity of C₆₀ fullerene nanowhisker–zeolitic imidazolate framework-67 composite for reduction of 4-nitrophenol

Abstract

The liquid–liquid interfacial precipitation method was used to prepare C₆₀ fullerene nanowhisker (FNW)–zeolitic imidazolate framework-67 (ZIF-67) composite from a ZIF-67 solution, C₆₀-saturated toluene, and isopropyl alcohol. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the synthesized C₆₀ FNW-ZIF-67 composite. Its catalytic activity for the reduction of 4-nitrophenol was confirmed by UV–visible (UV-vis) spectroscopy. C₆₀ FNW–ZIF-67 as a catalyst displayed a reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) for 20 min with a rate constant of 1.379 × 10⁻¹min⁻¹ (at 25 °C), 5.761 × 10⁻²min⁻¹ (at 15 °C), and 3.113 × 10⁻²min⁻¹ (at 5 °C), respectively. A kinetics study indicated that the hybrid nanocomposite catalyzed the reduction of 4-nitrophenol according to a pseudo-first-order reaction rate equation. The thermodynamic parameters of activation, namely, the enthalpy of activation (ΔH) of 48.966 kJ mol⁻¹, the entropy of activation (ΔS) of −97.479 J mol⁻¹ K⁻¹, and the activation energy (ΔE_a) of 51.167 kJ mol⁻¹, were obtained using the Eyring and Arrhenius equations.

Keywords:

• C₆₀ FNW
• ZIF-67
• catalytic activity
• reduction
• 4-nitrophenol

Additional information

Funding

This study was supported by research funding from Sahmyook University in Korea.