Development of an electroconductive carbon fiber/circulating fluidized bed fly ash based-geopolymer composite for high-efficiency treatment of dye wastewater

Abstract

This study proposed a novel electroconductive carbon fiber/circulating fluidized bed fly ash based-geopolymer (CF/CFBFAG) composite, which possessed adjustable electrical conductivity and showed a promising prospect in photocatalytic degradation of dye wastewater. SEM results indicated that carbon fiber was inlaid in the geopolymer matrix uniformly. The electrical conductivity of the CF/CFBFAG composite with 15% CF (15CF/CFBFAG) achieved 8.44 S/m, which was 44.4 thousand times as high as that of the composite without CF. UV-Vis DRS and PL spectra result demonstrated that the absorption edges of the CF/CFBFAG composite was blue-shifted and the photoluminescence intensities gradually decreased with increasing of CF content. The photocatalytic degradation for 5 mg/L of basic violet 5BN (BV5) dye over 15CF/CFBFAG composite can achieve 98.9%. Superoxide radical (·O₂⁻) and photogenerated hole (h⁺) were the predominant active species in this system.

Keywords:

• Carbon fiber
• geopolymer
• composite
• photocatalytic degradation
• dye wastewater

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Grant No. 21676209), the Key Research and Development Project of Shaanxi Province (Grant No. 2019GY-137), and the Cultivating Fund of Excellent Doctorate Thesis of Xi’an University of Architecture and Technology (Grant No. 6040318008).