ZnO decorated on low carbonate NiAl-layered double hydroxide as efficient photocatalyst for methyl orange degradation

Abstract

The decoration of zinc oxide (ZnO) nanorods on layered structure of low carbonate NiAl-layered double hydroxide (NiAl-LDH) was conducted by a combination of an aqueous solution of zinc chloride and an aqueous suspension of NiAl-LDH under hydrothermal method and subsequent calcination at 250 °C for 6 h. A series of the products, ZnO/NiAl-LDH(x), where x was a Zn2+ content, were characterized by X-ray diffraction, transmission electron microscopy, surface analysis, as well as UV–visible and photoluminescence spectroscopies. The slight shift of the reflection at around 11° as well as the appearance of two peaks at around 23° and 47° in the X-ray diffraction patterns, and the decrease of the vibration mode of CO32‐− (at 1359 cm−1) in Fourier transform infrared spectra confirmed the deintercalation of CO32− on/in layered double hydroxide. The presence of the reflections due to zinc oxide at around 32°, 33° and 36° and transmission electron microscope images demonstrated the images of zinc oxide nanorods distributed on the external surface of the hexagonal plates of the layered double hydroxide, verified the formation of zinc oxide crystal in the products. The band gap energy value of the products was highly dependent on the amount of zinc oxide in the products that played an important role in the photodegradation enhancement of methyl orange in aqueous solution and the catalytic reusing performance.