Preparation and performance study of Mn-doped TiO₂-loaded kapok-based activated carbon fibers

Abstract

Due to its various advantages, such as a large specific surface area, high adsorption capacity, rapid adsorption rate, and moderate pore size, activated carbon fiber (ACF) has been extensively employed in wastewater treatment. In this study, the sol–gel-adsorption method was utilized to effectively synthesize Mn-doped TiO₂-loaded kapok-based activated carbon fibers (Mn-TiO₂/ACF). Several characterization techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen adsorption-desorption were employed to investigate the Mn-TiO₂/ACFs. The resulting Mn-TiO₂/ACFs exhibited a combination of anatase and rutile forms in the produced TiO₂. The introduction of Mn doping was found to hinder the crystal development, agglomeration, and crystallization of TiO₂. The Mn-doped TiO₂/ACFs demonstrated significant visible-light photocatalytic activity, attributed to the synergistic effects of two factors: the photocatalytic degradation of TiO₂ films and the absorption capacity of ACF. The optimal molar ratio (Mn: Ti) for Mn-TiO₂/ACFs in visible-light photocatalytic applications was determined to be 1:150. A pseudo-second-order kinetics model was employed to investigate the adsorption process of methyl bromide on Mn-TiO₂/ACFs samples. The experimental results indicated that Mn-TiO₂/ACF was reusable, with a removal efficiency exceeding 53% for all five cycles.

Keywords:

• Activated carbon fiber
• sol–gel method
• TiO₂
• absorption kinetics
• specific surface area

Acknowledgment

The authors acknowledge the support of the analysis and measurement center of Wuhan Textile University.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was sponsored by the National Nature Science Fund of China (51303139).