Facile fabrication of Fe-BDC/Fe-2MI heterojunction with boosted photocatalytic activity for Cr(VI) reduction. Issue 5 (October 2021)

• Record Type: Journal Article
• Authors: He, Qin; Fu, Yangjie; Ge, Xueying; Al-Enizi, Abdullah M.; Nafady, Ayman; Wang, Qi; Ma, Shengqian
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 5(2021)
• Publication Date: 2021-10
• Subjects: Fe-BDC -- Fe-2MI -- Heterojunction -- Photocatalysis -- Cr(VI) reduction -- MOF; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105961
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Novel Fe-BDC/Fe-2MI heterojunction (H2 BDC: terephthalic acid, 2MI: 2-methylimidazole) was prepared via a one-pot solvothermal method. Herein, mixed ligands (H2 BDC and 2MI) was applied to form complex with Fe(III). Interestingly, the presence of 2MI can regulate the structure of Fe-BDC. Spindle-like MIL-88B(Fe) was observed in Fe-BDC/Fe-2MI composite, while MIL-53(Fe) was identified in naked Fe-BDC. By employing photoelectrochemical characterizations, Fe-BDC/Fe-2MI was optimized at an initial molar ratio of 1:0.5:10 for Fe(III):H2 BDC:2MI, which exhibited the highest photocurrent response, lowest charge transfer resistance, and fastest surface reaction kinetics as compared to the individual Fe-BDC and Fe-2MI. Due to the formation of the heterojunction which lead to beneficial photoelectrochemical properties, the as-prepared samples exhibited boosted photocatalytic activity for Cr(VI) reduction. The calculated pseudo-first-order rate constant ( k ) was 0.046 min −1 for Fe-BDC/Fe-2MI, which was 15.3 and 6.6 times that of Fe-BDC (0.003 min −1 ) and Fe-2MI (0.007 min −1 ), respectively. Moreover, the optimized Fe-BDC/Fe-2MI demonstrated superior performance with negligible loss in activity after 4 cyclic runs. Graphical Abstract: ga1 Highlights: Fe-BDC/Fe-2MI heterojunction was prepared using H2 BDC and 2MI as mixed ligands. The presence of 2MI can regulate the structure of Fe-BDC from MIL-53 to MIL-88B. The optimized sample displayed boosted and stable photocatalytic activity. A 15.3 times rate enhancement for Cr(VI) reduction can be achieved.