In situ fabrication of I-doped Bi2O2CO3/g-C3N4 heterojunctions for enhanced photodegradation activity under visible
Yunlong Lan1, Zesheng Li2, Wenyu Xie2
1Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China; State Key Laboratory of Heavy Oil Processing, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum, Beijing 102249, China.
Abstract:
Iodine-doped Bi2O2CO3/g-C3N4 heterojunctions consisting of graphitic carbon nitride (g-C3N4) and iodine-doped bismutite (Bi2O2CO3) components were successfully in situ synthesized by a one-pot hydrothermal method. Characterizations such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) demonstrated iodine was favorably doped into the Bi2O2CO3 component, of which the {001} facets grew in situ from {002} facets of g-C3N4 for the heterostructure construction of I-doped Bi2O2CO3/g-C3N4 (IB/CN). The photocatalytic activity of catalysts was evaluated by the degradation efficiency of 1,5-dihydroxynaphthalene under visible light. 1.5-IB/CN with a reasonable iodine doping amount (Bi: I molar ratio = 1.0: 1.5) exhibited the superior photodegradation performance compared to Bi2O2CO3, achieving an 85.5% removal ratio after 100 min illumination. The enhanced activity of 1.5-IB/CN was attributed to both of the heterostructure that promoted the separation of photoinduced carriers and iodine doping that tuned the bandgap for sufficient visible-light harvesting. The degradation intermediates of 1,5-dihydroxynaphthalene in the system were determined and its possible photodegradation pathway was proposed in detail. This study provides a rational approach for enhancing the visible-light catalytic activity of wide-bandgap Bi2O2CO3, and reveals a new perspective on the removal mechanism of organic pollutants.
