Multiwalled carbon nanotube-supported CuCo₂S₄ as a heterogeneous Fenton-like catalyst with enhanced performance

Abstract

In this paper, we prepared CuCo 2 S 4 /MWCNTs as a heterogeneous iron-free bimetal catalyst for the degradation of methylene blue (MB) dye by uniformly synthesizing CuCo 2 S 4 nanoparticles on the surfaces of multiwalled carbon nanotubes (MWCNTs). The homogeneous nanostructure, tuned by MWCNTs, and the efficient electron transfer from CuCo 2 S 4 to MWCNTs resulted in a quite decent catalytic activity, which was superior to that of pristine CuCo 2 S 4 and monometal sulfides. Moreover, CuCo 2 S 4 /MWCNTs maintained a good catalytic performance over a broad pH range of 3 to 12, and exhibited better MB degradation rates under alkaline conditions. Meanwhile, the catalyst was reusable for up to three cycles due to the strong interaction between the nanoparticles and MWCNTs. The results demonstrate that CuCo 2 S 4 /MWCNTs is an improved Fenton catalyst and a promising candidate to substitute iron-based catalysts for the treatment of wastewater containing dyes.

Cobalt and Copper Ions Synergistically Enhanced Photochemical Vapor Generation of Molybdenum: Mechanism Study and Analysis of Water Samples

“…Also, larger quantities of • CO 2 – were produced with prolonged irradiation time (Figure D), as well as with concomitant Co 2+ and Cu 2+ (Figure B), in accordance with the observation that an UV exposure time of 60 s was necessary for efficient PCVG of Mo. Such a synergistic effect of two or more kinds of metals, not surprisingly, was found in heterogeneous di- or polymetal oxides (Ce–Mn, Co–Cu) and sulfides (Ni–Mo, Co–Cu) possessing outstanding catalytic or electrochemical properties and proposed for treatment of dye-containing wastewater as an alternative iron-free Fenton catalyst . With respect to the homogeneous PCVG reactions, abundant reactive free radicals (e.g., • OH and • CO 2 – as trapped by DMPO) were produced, and thus it was highly possible to generate a thermodynamically favored Cu­(I)/Co­(III) redox couple other than Cu­(I)/Cu­(II) and Co­(II)/Co­(III), which in turn accelerated the photolysis of formic acid.…”

Multi‐walled carbon nanotubes supported amorphous Fe2O3 and Ag2O–Fe2O3 as Fenton catalysts for degradation of maxilon red dye

“…Serp et al studied the catalytic performance of carbon nanotubes and carbon nanofibers and found that CNTs were promising and competitive supports as compared with carbon nanofibers because of their large surface area, stability, and adsorption properties. Lately, Zhang et al investigated the degradation of methylene blue dye over iron‐metal‐free bicatalysts of CuCo 2 S 4 and CuCo 2 S 4 /MWCNTs composite. They found that the combination of CuCo 2 S 4 with MWCNTs gave rise to yield a promising heterogeneous Fenton‐like catalyst used in dye‐contaminated wastewater without any pH limitations.…”