Photocatalytic degradation of methylene blue and methyl orange in a Zn(II)-based Metal–Organic Framework

Abstract

A novel 3D Zn(II)-based metal-organic framework [Zn₂(odpt)(bpy)(H₂O)](bpy)_0.5 (1) (H₄odpt = 4,4′-oxidiphthalic acid, bpy = 4,4′-bipydine) has been hydrothermally synthesized, and characterized by the single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, UV–vis diffuse spectrum, and thermal gravimetric analysis. Compound 1 shows highly efficient photocatalytic activity on the degradation of individual methylene blue (MB) and methyl orange (MO), while exhibits a preferential photocatalytic degradation of MO in the MO/MB mixture under UV light irradiation. The possible photocatalytic mechanism was proposed, which was confirmed by trapping experiments of radicals via the addition isopropanol as radical scavenger, and compound 1 exhibits excellent recyclability and stability, which can achieve good degradation efficiency to MB for five runs.

Keywords:

• Metal-organic framework
• Photocatalytic degradation
• Diffuse reflectance
• Photocatalytic mechanism

Acknowledgments

We thank the financial support from National Natural Science Foundation of China (5178013), the Beijing Natural Science Foundation & Scientific Research Key Program of Beijing Municipal Commission of Education (KZ201410016018), the Training Program Foundation for the Beijing Municipal Excellent Talents (2013D005017000004), the Importation & Development of High-Caliber Talents Project of Beijing Municipal Institutions (CIT&CD201404076), Special Fund for Cultivation and Development Project of the Scientific and Technical Innovation Base (Z141109004414087).