One pot synthesis of α-Fe2O3/turbostratic carbon composites and their photocatalytic activity under sunlight

Abstract

Sucrose naturally obtained from sugar cane was catalytically graphitized by incorporation of varying amounts of iron (1, 5, 7.5 and 10%) as a one-pot synthesis. The weight of iron was varied relative to the weight of sucrose. Synthesized sucrose-Fe 2 O 3 nanocomposites (FeGC) were characterized by X-ray diffractometry (XRD), Raman spectroscopy, and UV-Visible spectroscopy. It is observed that turbostratic carbon is produced upon the incorporation of iron and the percentage of graphitization increase with increasing loading of iron as revealed by XRD analysis. Quantitative analysis of Raman spectra confirm that the ordering of carbon increase with increasing loading of iron. The equilibrium adsorption capacity of carbon with the highest iron loading (10FeGC), 0.50 mg/g is higher than that with carbon without any metal, AC (0.2 mg/g), and the highest adsorption capacity (0.58 mg/g) resulted in carbon with 5% iron (5FeGC). Methylene blue adsorption to AC and carbon with 1% iron (1FeGC) followed pseudo-first-order kinetics and carbon materials with 5, 7.5 and 10% iron followed pseudo-second-order kinetics. The initial rate constant for the photodegradation of methylene blue in the presence of AC was 0.001 min −1 and that of 1FeGC (0.005 min −1 ) increased with increasing loading of iron where the highest initial rate constant (0.158 min −1 ) was obtained with 10FeGC. Ordered carbon enhances photocatalytic activity by being photoactive and increasing the separation of charges generated at α-Fe 2 O 3 .