Chitosan adorned with ZIF-67 on ZIF-8 biocomposite: A potential LED visible light-assisted photocatalyst for wastewater decontamination

Abstract

The current investigation has utilized a simple and constructive stratified method to synthesize a binary (Cs/Z-8: chitosan (Cs) and zeolitic imidazolate framework-8 (Z-8)) and ternary Cs/Z-8/Z-67 (Z-67: ZIF-67) biocomposites at room temperature. A certain amount of Cs/Z-8 (0.05, 0.1, and 0.2 g) was used to prepare ternary biocomposites (denoted as Cs/Z-8/Z-67-0.05, Cs/Z-8/Z-67-0.1, and Cs/Z-8/Z-67-0.2, respectively). The synthesized materials were characterized. Through the adornment Cs, a non-toxic biopolymer, with Z-8 and Z-67, the desired efficacy in removing pollutants (TCN: Tetracycline, AB92: Acid Blue 92, and MB: Methylene Blue) was achieved under LED visible light. TCN removal in the presence of visible light by Cs, Z-8, Cs/Z-8, Cs/Z-8/Z-67-0.05, Cs/Z-8/Z-67-0.1, and Cs/Z-8/Z-67-0.2 was 22.6 %, 47.3 %, 69.0 %, 77.0 %, 95.5 %, and 65.0 %, respectively. The trapping test showed that TCN degradation by adding ascorbic acid, methanol, and IPA was 44.8 %, 66.9 %, and 78.5 %, respectively. It could be concluded that the O₂^- play the decisive role for the destruction of TCN. The reusability of Cs/Z-8/Z-67-0.1 as a photocatalyst indicated that it had the capability to preserve its stability and performance for three successive cycles of use (95.5 %, 89.0 %, and 84.0 %). Also, Cs/Z-8/Z-67 had dye degradation ability (39.0 % for Methylene Blue and 81.0 % for Acid Blue 92).

Keywords: Chitosan/ZIF-8/ZIF-67; Environmentally friendly; Ternary biocomposite; Tetracycline and dyes removal; Visible light-assisted photocatalyst.