Synthesis of Core/Shell ZnO/rGO Nanoparticles by Calcination of ZIF-8/rGO Composites and Their Photocatalytic Activity

Batukhan Tatykayev; Florian Donat; Halima Alem; Lavinia Balan; Ghouti Medjahdi; Bolat Uralbekov; Raphaël Schneider

doi:10.1021/acsomega.7b00673

Synthesis of Core/Shell ZnO/rGO Nanoparticles by Calcination of ZIF-8/rGO Composites and Their Photocatalytic Activity

ACS Omega. 2017 Aug 24;2(8):4946-4954. doi: 10.1021/acsomega.7b00673. eCollection 2017 Aug 31.

Authors

Batukhan Tatykayev¹, Florian Donat², Halima Alem³, Lavinia Balan⁴, Ghouti Medjahdi³, Bolat Uralbekov¹, Raphaël Schneider²

Affiliations

¹ Al-Farabi Kazakh National University, Al-Farabi Avenue, 71, 050040 Almaty, Kazakhstan.
² Université de Lorraine, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, CNRS, 1 rue Grandville, BP 20451, 54001 Nancy Cedex, France.
³ Institut Jean Lamour (IJL), Université de Lorraine, CNRS, UMR 7198, CNRS, BP 70239, 54506 Vandoeuvre-lès-Nancy Cedex, France.
⁴ Institut de Science des Matériaux de Mulhouse (IS2M), CNRS, UMR 7361, 15 rue Jean Starcky, 68093 Mulhouse, France.

Abstract

A facile two-step method was developed to prepare core/shell ZnO/rGO particles from ZIF-8/rGO composites. ZIF-8 particles were first grown at the surface of rGO sheets. Next, ZIF-8 particles were transformed into ZnO particles by thermal decomposition under air at 500 °C. All materials were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and Brunauer-Emmett-Teller analyses. Results obtained show that ZIF-8 particles strongly associate with rGO sheets and that the calcination of this material produces porous core/shell ZnO/rGO particles with an average diameter of ca. 40 nm. The wt % of rGO associated with ZIF-8 particles was varied from 5 to 20%. The ZnO/rGO (10%) particles exhibit the highest photocatalytic activity for the degradation of the Orange II dye under simulated solar light irradiation of weak intensity (5 mW/cm²). This high photocatalytic activity was demonstrated to originate from superoxide O₂ ^•- radicals due to the efficient trapping of photogenerated electrons in ZnO by rGO.