ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Efficient catalytic reduction of hazardous hexavalent chromium by cobalt sulfide nanoparticles

K. Arathi, T. N. Ravishankar, Kalyan Raj, and K. L. Nagashree

Centre for Nanoscience and Nanotechnology, Department of Chemistry, Global Academy of Technology, Bengaluru, India

E-mail: nagashreekl.chem@bmsce.ac.in

Received: 27 January 2021  Accepted: 12 April 2021

Abstract:

Abstract

Aiming at the catalytic reduction of hazardous hexavalent chromium, cobalt sulfide nanoparticles (CoS₂ NPs) were synthesized solvothermally from 1:1 v/v ratio of methanol and water. The nanoparticles were characterized by XRD, SEM, TEM, FTIR and BET for their composition, crystal structure, morphology and specific surface area. Reduction of carcinogenic hexavalent chromium to non-toxic trivalent chromium was found to occur efficiently on these CoS₂ NPs. Effect of various parameters such as catalyst loading, initial chromium concentration, pH, reaction time and recyclability was studied. At pH 2 in sulfuric acid, reduction of 50 mL of 50 ppm Cr(VI) with 1.5 g/L of catalyst was found to be complete within 16 min with ~ 99.63% efficiency. The catalyst was found to be efficient up to 17 cycles after which the activity decreased. Column studies with effluent sample from electroplating industry indicated that these nanoparticles are promising for treatment of chromium contaminated industrial water.

Graphic abstract

Keywords: Chromium reduction; Cobalt sulfide nanoparticles; Solvothermal synthesis; Water treatment

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01655-2

Chemical Papers 75 (9) 4707–4718 (2021)