Fabrication of Nanometer-Sized Nickel-Based Metal Organic Frameworks on Carbon Nanotubes for Electro-Catalytic Oxidation of Urea and Arsenic Removal

Even though metal organic frameworks (MOFs) have rapidly emerged as useful materials in many applications, their inherent low conductivity necessitate hybridizing them with conductive carbon nanostructures like graphene or carbon nanotubes (CNTs) or carbon black especially in energy storage and energy generation applications like batteries, super capacitors, and electro-catalysts in oxygen reduction reaction (ORR). However, to date the synthesis of MOF/CNT is carried out by mixing pre-synthesized MOFs with oxidized or chemically modified CNTs. In this article, we report synthesis of nanometer-sized Ni-MOF/CNT by the reaction of nickelocene-derived nickel oxide-decorated CNTs with terepthalic acid synthesized from waste polyethylene terephthalate (PET ). Morphological studies by scanning electron microscopy and transmission electron microscopy shows nanometer-sized Ni-MOF particles anchored on defect-rich carbon nanotubes, whereas the chemical changes associated wit transformation of NiO@CNT into nanometer-sized Ni-MOF/CNT were evaluated by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy analysis. The utility of nanometeric Ni-MOF/CNT as an electro-catalyst in urea oxidation reactions and removal of arsenic from contaminated water is reported. The applicability of our developed technique to synthesize nanometer Fe-MOF/CNT is also demonstrated.