Oxidative Degradation of Organic Dyes Over Supported Perovskite Oxide LaFeO3/SBA-15 Under Ambient Conditions

Abstract

Supported perovskite oxide, LaFeO3/SBA-15, is investigated for the first time as catalyst for the oxidation of organic dyes using hydrogen peroxide as oxidant. Characterizations such as XRD, XPS, TEM and N2 physisorption isotherms indicate that the supported catalyst has typical perovskite LaFeO3 structure, and the ordered mesoporous structure of SBA-15 remains unchanged after the formation of LaFeO3. Catalytic tests indicate that LaFeO3/SBA-15 has large adsorption capacity, good catalytic performances, and wide working pH ranges (from 2 to 10) for the oxidation of dyes, e.g., Rhodamine B. Moreover, the catalyst can be reused for at least four times without appreciable loss in the activity, and no dissolved Fe3+ ion could be detected by atomic absorption spectrometry after the reaction, suggesting that LaFeO3/SBA-15 is a very stable and active catalyst for the oxidation of dyes in aqueous solution. Comparative tests on various organic dyes, such as reactive brilliant red X-3B, direct scarlet 4BS, methylene blue and Rhodamine B (RhB), indicate that LaFeO3/SBA-15 is more favorable for RhB oxidation, while considerable activity could also be available for other dyes, potentiating its wide applications for industrial removal of dyes. The excellent catalytic performances of LaFeO3/SBA-15 could be attributed to the synergistic effect between SBA-15 and LaFeO3. Supported perovskite oxide LaFeO3/SBA-15 shows active and stable catalytic activity for the oxidative removal of organic dyes using H2O2 as oxidant