Iron-loaded carbon black prepared via chemical vapor deposition as an efficient peroxydisulfate activator for the removal of rhodamine B from water

Harez R Ahmed; Kosar Hikmat Hama Aziz; Nian N M Agha; Fryad S Mustafa; Steven John Hinder

doi:10.1039/d3ra04566h

Iron-loaded carbon black prepared via chemical vapor deposition as an efficient peroxydisulfate activator for the removal of rhodamine B from water

RSC Adv. 2023 Sep 4;13(37):26252-26266. doi: 10.1039/d3ra04566h. eCollection 2023 Aug 29.

Authors

Harez R Ahmed^{1

2}, Kosar Hikmat Hama Aziz^{1

3}, Nian N M Agha^{1

2}, Fryad S Mustafa¹, Steven John Hinder⁴

Affiliations

¹ Department of Chemistry, College of Science, University of Sulaimani Qlyasan Street Sulaimani City 46001 Kurdistan Region Iraq kosar.hamaaziz@univsul.edu.iq harez.ahmed@univsul.edu.iq.
² College of Science, Department of Medical Laboratory Science, Komar University of Science and Technology Sulaimani 46001 Iraq.
³ Department of Medical Laboratory of Science, College of Health Sciences, University of Human Development Sulaimaniyah Iraq.
⁴ Department of Mechanical Engineering Sciences, Faculty of Engineering and Physical Sciences, University of Surrey Guildford Surrey GU2 7XH UK.

Abstract

The excessive use of organic pollutants like organic dyes, which enter the water environment, has led to a significant environmental problem. Finding an efficient method to degrade these pollutants is urgent due to their detrimental effects on aquatic organisms and human health. Carbon-based catalysts are emerging as highly promising and efficient alternatives to metal catalysts in Fenton-like systems. They serve as persulfate activators, effectively eliminating recalcitrant organic pollutants from wastewater. In this study, iron-loaded carbon black (Fe-CB) was synthesized from tire waste using chemical vapor deposition (CVD). Fe-CB exhibited high efficiency as an activator of peroxydisulfate (PDS), facilitating the effective degradation and mineralization of rhodamine B (RhB) in water. A batch experiment and series characterization were conducted to study the morphology, composition, stability, and catalytic activity of Fe-CB in a Fenton-like system. The results showed that, at circumneutral pH, the degradation and mineralization efficiency of 20 mg L^-1 RhB reached 92% and 48% respectively within 60 minutes. Fe-CB exhibited excellent reusability and low metal leaching over five cycles while maintaining almost the same efficiency. The degradation kinetics of RhB was found to follow a pseudo-first-order model. Scavenging tests revealed that the dominant role was played by sulfate (SO₄^-˙) and superoxide (O₂^-˙) radicals, whereas hydroxyl radicals (OH˙) and singlet oxygen (¹O₂) played a minor role in the degradation process. This study elucidates the detailed mechanism of PDS activation by Fe-CB, resulting in the generation of reactive oxygen species. It highlights the effectiveness of Fe-CB/PDS in a Fenton-like system for the treatment of water polluted with organic dye contaminants. The research provides valuable insights into the potential application of carbon black derived from tire waste for environmental remediation.