Synthesis of iron triad metals-modified graphitic mesoporous carbon for methylene blue photodegradation

Abstract

Photoactive metal on graphitic mesoporous carbon (GMC-M; M=Fe, Ni, Fe-Ni and Co-Ni) was obtained from hard templating synthesis method while using sucrose as carbon precursor. Sucrose was deposited on metal/SBA-15 followed with carbonization and pyrolysis to obtain readily incorporated Fe, Ni, Fe-Ni and Co-Ni on GMC. GMC-M was characterized using XRD, FTIR, N2 Adsorption Desorption and Raman spectroscopy. All the analytical results showed the mesoporous carbon has a highly ordered graphitic structure which was proven by Raman that shows an increase in the ratio of ID/IG from ordinary GMC to GMC-M (M=Fe, Co, Ni) as a phenomenon of increasing structural regularity. The photodegradation activity of GMC-M was investigated for degradation of methylene blue (MB) in synthetic wastewater. The photodegradation of MB was carried out under ultraviolet light (UV) irradiation and in the presence of hydrogen peroxide (H2O2). All the catalysts partially degraded methylene blue within 60 min with the efficiency varied 40% to 80% MB, indicating the promotion of GMC into photoactive material with metal addition. Degradation of MB under UV-H2O2 using GMC-Fe system resulted in 96% efficiency than the UV only. The present study showed that the UV-oxidant/catalyst process significantly enhanced the degradation of MB in comparison to direct photolysis by UV.