Nickel hydroxide nanoparticles decorated napthalene sulfonic acid-doped polyaniline nanotubes as efficient catalysts for nitroarene reduction

Venkata Satyanarayana Sypu; Madhumita Bhaumik; Kumar Raju; Arjun Maity

doi:10.1016/j.jcis.2020.08.111

Nickel hydroxide nanoparticles decorated napthalene sulfonic acid-doped polyaniline nanotubes as efficient catalysts for nitroarene reduction

J Colloid Interface Sci. 2021 Jan 1;581(Pt B):979-989. doi: 10.1016/j.jcis.2020.08.111. Epub 2020 Sep 9.

Authors

Venkata Satyanarayana Sypu¹, Madhumita Bhaumik², Kumar Raju³, Arjun Maity⁴

Affiliations

¹ Department of Chemical Science, University of Johannesburg, Johannesburg, South Africa.
² Chemical Engineering Department, University of Pretoria, South Africa.
³ Energy Centre, Council for Scientific and Industrial Research (CSIR), Pretoria 0001, South Africa.
⁴ Department of Chemical Science, University of Johannesburg, Johannesburg, South Africa; DST/CSIR, Centre for Nanostructure and Advanced Materials (CeNAM), Council for Scientific and Industrial Research (CSIR), Pretoria 0001, South Africa. Electronic address: amaity@csir.co.za.

PMID: 32961349
DOI: 10.1016/j.jcis.2020.08.111

Abstract

Nanosize nickel hydroxide decorated 2-napthalene sulfonic acid-doped polyaniline nanotubes nanocomposites (Ni(OH)₂@NSA-PANI NCs) were successfully developed for the catalytic reduction of aromatic nitro compounds. The Ni(OH)₂@NSA-PANI NCs were synthesised by depositing Ni(OH)₂ nanoparticles onto 2-napthalene sulfonic acid doped PANI nanotubes surface. The resulting material was characterized using field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (P-XRD), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The prepared nanocomposite showed a remarkable ability to catalytically hydrogenate aromatic nitro compounds using sodium borohydride (NaBH₄) as hydrogen source in aqueous medium at room temperature. Kinetic studies were performed using 4-nitrophenol (4-NP) as the model substrate, using the Langmuir-Hinshelwood model. The catalyst showed pseudo-first-order kinetics, with rate constants estimated between 0.08287 and 0.3649 min^-1. Catalyst recyclability without reduced activity was demonstrated over 10 successive cycles. The optimised nanocomposite catalyst demonstrated a low activation energy barrier towards 4-NP reduction.

Keywords: Aqueous medium; Ni(OH)(2) nanoparticles; Nitroarene reduction; Polyaniline nanotube; Recyclability.