ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Microfluidics-facilitated spontaneous synthesis of ZIF-67 metal–organic framework

Svapnil Kevat and V. N. Lad

Department of Chemical Engineering, Sardar Vallabhbhai National Institute of Technology - Surat, Surat, India

E-mail: vnl@ched.svnit.ac.in

Received: 5 January 2023  Accepted: 21 June 2023

Abstract:

Zeolitic imidazolate framework (ZIF) materials are thermally and chemically stable, and suitable for many possible applications, including chemical sensors, gas separation, energy storage, catalysis, etc. However, the conventional synthesis techniques of ZIFs need to be revisited to make them time-efficient and cost-effective with better process control. Here we show the potential of microfluidics for the synthesis of ZIF, resulting in improved porosity, surface morphology and stability. Four distinct operating conditions were used to synthesize ZIF-67 metal–organic framework, viz. sonication at room temperature, without sonication at room temperature, 70 °C, and 120 °C, using a fully continuous microfluidic technique incorporating a T-type micromixer connected to a helical microfluidic flow reactor (HMFR). ZIF-67 is synthesized in methanol at a constant metal salt/ligand ratio of 1:8 without adding modulators such as capping agents and surfactants. We used a T-micromixer coupled with a helically wound microfluidic tubing for the first time to synthesize the crystalline ZIF-67 resulting in synthesis of high quality ZIF through the continuous and time-effective processing route. The samples were characterized using FESEM, TEM, XPS, XRD, BET, TGA and FTIR which showed remarkable characteristics of ZIF-67 useful for many applications.

Keywords: Continuous flow synthesis; Metal–organic framework MOF; Microfluidics; Zeolitic imidazole framework; ZIF-67

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02944-8

Chemical Papers 77 (10) 6351–6363 (2023)