Photocatalytic degradation of reactive dyes over NiAl layered double hydroxide

Abstract

Due to the uncontrolled discharge of textile effluents, the extent of reactive dyes in wastewater is rising. Due to their toxicity, efficient removal becomes quite essential. In this report, NiAl layered double hydroxide (LDH) has been prepared using the coprecipitation methodology for the photocatalytic degradation of reactive dyes. The as-prepared materials were characterized by different techniques, such as DRS, XRD, FESEM, HRTEM, and XPS etc. The XRD pattern of the LDH confirms the formation of the rhombohedral (R3m) phase. The FESEM analysis reveals the irregular hexagon-like shape of the prepared LDH. The NiAl LDH has 98(1) and 87(1)% photodegradation efficiencies towards the removal of reactive blue 19 and reactive Red 120, respectively. The control experiments in the presence of different scavengers confirm that hydroxyl radicals and superoxide anions participate in photocatalytic degradation. The HRMS studies confirm the formation of different smaller fragments, thereby providing a deeper insight into the photodegradation mechanism. Moreover, the demineralization efficiency (88.9%) is quite close to the degradation efficiency for reactive blue 19, signifying practically complete demineralization of the pollutants. The recyclability studies ascertain the high stability of the photocatalyst. Therefore, the as-prepared NiAl LDHs can be considered a promising photocatalyst for the removal of reactive dyes from wastewater.