Design and Fabrication of a Retrievable Magnetic Halloysite Nanotubes Supported Nickel Catalyst for the Efficient Degradation of Methylviolet 6B and Acid Orange 7

Abstract

Magnetic halloysite nanotubes based organic-inorganic hybrid materials have elicited ripples of excitement in the area of water research and technology by the virtue of their hollow nanotubular structure, presence of adequate hydroxyl groups and tunable surface chemistry. Fascinated by these riveting benefits, a nickel based nanocatalyst has been designed wherein a bidentate chelating ligand "4-aminoantipyrine (AA)" was anchored onto the surface of aminosilane functionalized magnetic halloysite nanotubes followed by its metalation. In a shorter time span of 30 min, the synthesized nanocatalyst showed outstanding degradation efficiency of 96.87 % and 96.22 % towards MV6B and AO7 respectively under neutral conditions. The ensuing nanocomposite in-situ generates * OH from H 2 O 2 that aided in rapid degradation of MV6B and AO7 into innocuous products with unprecedented efficacy. Besides, the impressive magnetic attributes of designed Ni(II)-@AA@APTES@MHNTs offer effortless magnetic retrievability with the aid of an external magnet and the catalyst could be recycled upto six consecutive runs. GC-MS analysis helped in identifying the generated degradation products and provided valuable insights into the plausible degradation pathway of pollutants followed during the reaction. Through various studies, it is believed that the peerless advantages of Ni(II)-@AA@APTES@MHNTs nanocatalyst will lay a foundation for treatment of wastewater containing devastating organic contaminants.