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

Photocatalytic efficiency of ZnAl-layered double hydroxide on degradation of a cationic dye under UV and solar radiation

Hassiba Bessaha, Charef Harrats, Mohamed Bouraada, and Louis Charles Deménorval

Université de Mostaganem, Mostaganem, Algeria

E-mail: hassiba2544@hotmail.fr

Abstract: UV and solar radiation photocatalytic degradation of basic dye Rhodamine B (RhB) using ZnAl-layered double hydroxide photocatalyst was investigated. ZnAl-layered double hydroxide (ZA4-HT) with a molar ratio of 4:1 was synthesized from zinc and aluminum salts by co-precipitation methods, followed by heat treatment at 500 °C (CZA4). Powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) revealed that after heat treatment of ZA4-HT, the pristine structure collapsed resulting in ZnO particles and ZnAl₂O₄ spinel. The discoloration rate of RhB was lower than 8% through direct photolysis. The calcined ZA4-HT showed high photocatalytic efficiency with a discoloration rate of about 100% after 90 min exposure time to UV or sunlight radiation. The optimal catalyst loading was found to be 1 g/L and the discoloration time increased with the dye concentration. The photodiscoloration and the photodegradation kinetics data were described by pseudo-first-order and Langmuir–Hinshelwood models. The reusability study of the calcined material showed a stable efficiency after four successive uses.

Keywords: Cationic dyes ; Langmuir–Hinshelwood model ; Layered double hydroxides ; Photocatalytic degradation ; UV irradiation ; ZnO particles 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-017-0347-9

Chemical Papers 72 (4) 1031–1040 (2018)