Fabrication of novel particle electrode γ-Al2O3@ZIF-8 and its application for degradation of Rhodamine B

Due to the high Brunauer-Emmett-Teller (BET) surface area of zeolitic imidazolate framework (ZIF)-8, a secondary crystallization method was used to prepare a particle electrode of γ-Al 2 O 3 @ZIF-8. According to the results from a field emission scanning electron microscope (SEM) and X-ray diffractometer (XRD), the particle electrode of γ-Al 2 O 3 was successfully loaded with ZIF-8, and the BET surface area (1,433 m 2 /g) of ZIF-8 was over ten times that of γ-Al 2 O 3 . The key operation parameters of cell voltage, pH, initial RhB concentration and electrolyte concentration were all optimized. The observed rate constant (k obs ) of the pseudo-first-order kinetic model for the electrocatalytic oxidation (ECO) system with the particle electrode of γ-Al 2 O 3 @ZIF-8 (15.2 × 10 -2 min -1 ) was over five times higher than that of the system with the traditional particle electrode of γ-Al 2 O 3 (2.6 × 10 -2 min -1 ). The loading of ZIF-8 on the surface of γ-Al 2 O 3 played an important role in improving electrocatalytic activity for the degradation of Rhodamine B (RhB), and the RhB removal efficiency of the three-dimensional (3D) electrocatalytic system with the particle electrode of γ-Al 2 O 3 @ZIF-8 was 93.5% in 15 min, compared with 27.5% in 15 min for the particle electrode of γ-Al 2 O 3 . The RhB removal efficiency was kept over 85% after five cycles of reuse for the 3D electrocatalytic system with the particle electrode of γ-Al 2 O 3 @ZIF-8.