Engineering the Cu2O–reduced graphene oxide interface to enhance photocatalytic degradation of organic pollutants under visible light

• Published in: Applied catalysis. B, Environmental Vol. 181; pp. 495 - 503
• Main Authors: Zou, Weixin, Zhang, Lei, Liu, Lichen, Wang, Xiaobo, Sun, Jingfang, Wu, Shiguo, Deng, Yu, Tang, Changjin, Gao, Fei, Dong, Lin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2016
• Subjects: Crystal-plane effect; Cu2O–rGO; Interfacial interaction; Superoxide radical; Visible-light degradation; Crystal-plane effect; Superoxide radical; Interfacial interaction; Visible-light degradation; Cu2O–rGO
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2015.08.017

[Display omitted] •The degradation activity was affected by the Cu2O–rGO interfacial structures.•O-Cu2O–rGO was helpful to the stabilization of Cu+ species and oxygen defect.•More superoxide radicals were observed over o-Cu2O–rGO under visible light.•O-Cu2O{111}–rGO had the superior property, for the advantageous interface. In this work, Cu2O–reduced graphene oxide (rGO) composites were synthesized with tunable Cu2O crystal facets ({111}, {110} and {100} facets). The degradation performance of methylene blue under visible light was ranked: o-Cu2O{111}–rGO>d-Cu2O{110}–rGO>c-Cu2O{100}–rGO. UV–vis diffuse reflectance and photoluminescence spectra showed that o-Cu2O–rGO exhibited the enhanced visible-light absorption and the faster charge-transfer rate. Furthermore, X-ray photoelectron spectroscopy and Raman characterizations showed that o-Cu2O–rGO was beneficial for the stabilization of Cu+ species and the formation of oxygen defects. With the help of in-situ electron spin resonance (ESR), more superoxide radicals were detected over o-Cu2O–rGO, which promoted organic pollutants degradation. The above results confirmed that the catalytic behaviors of three Cu2O–rGO composites were related to the electronic structures and interfacial connections. The o-Cu2O{111}–rGO displayed the superior performance, for the highly-active coordinated unsaturated Cu and the intensive interfacial connection, which was beneficial for the rapid the photo-generated electron transfer and the formed active superoxide species. This study showed that engineering the interfacial structures could provide a scientific basis for the design of efficient photo-catalysts.