Facile fabrication of a direct Z-scheme Ag2CrO4/g-C3N4 photocatalyst with enhanced visible light photocatalytic activity

• Published in: Journal of molecular catalysis. A, Chemical Vol. 421; pp. 209 - 221
• Main Authors: Deng, Yaocheng, Tang, Lin, Zeng, Guangming, Wang, Jiajia, Zhou, Yaoyu, Wang, Jingjing, Tang, Jing, Liu, Yani, Peng, Bo, Chen, Fei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2016
• Subjects: Ag2CrO4; g-C3N4 nanosheets; Photocatalyst; Visible light; Z-scheme; Ag2CrO4; Visible light; Z-scheme; g-C3N4 nanosheets; Photocatalyst
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2016.05.024

[Display omitted] •A Z-scheme Ag2CrO4/g-C3N4-N photocatalyst was prepared successfully;.•The high surface areas of the g-C3N4-N can prevent the aggregation of Ag2CrO4 nanoparticles;.•The synergistic effect between Ag2CrO4 and g-C3N4-N promoted the separation of charges;.•Enhanced photocatalysis was achieved via Z-scheme Ag2CrO4/g-C3N4-N photocatalysts. Graphite-like carbon nitride (g-C3N4) and silver-based compounds have attracted considerable attentions due to their excellent optical characteristic and photocatalytic performance. In this work, Z-scheme silver chromate-g-C3N4 nanosheets photocatalysts were prepared by binding growth of Ag2CrO4 nanoparticles on the surface of g-C3N4 nanosheets (g-C3N4-N) via a facile precipitation method. The morphologies, structure, specific surface area and optical property of the prepared photocatalysts were characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution-transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV-vis DRS) and photoluminescence (PL) spectra. The photocatalytic performances of the prepared Ag2CrO4/g-C3N4-N were evaluated by photodegradation of methyl orange (MO) and rhodamine B (RhB) under visible light irradiation (λ>400nm). The experiment results indicated that Ag2CrO4/g-C3N4-N composites presented enhanced photocatalytic activity and stability in the degradation of the dye contaminants in aqueous solution. The optimal composites with the mass ratio of Ag2CrO4 to g-C3N4-N as 50% (CNA-50) showed the highest photocatalytic activity for MO degradation, which is 5.9 and 10.8 times than those of pure Ag2CrO4 and pure g-C3N4-N, respectively. The formation of Ag2CrO4/g-C3N4-N Z-scheme heterojunction contributed to the improved photodegradation efficiency, which can not only promote the separation and transportation efficiencies of the photogenerated electron-hole pairs, but also present strong redox ability. And meanwhile the excellent transportation efficiency of the photogenerated electrons from Ag2CrO4 to g-C3N4-N greatly hindered the photocorrosion of Ag2CrO4 nanoparticles. This work provides a new understanding into the mechanism of the g-C3N4-N based composite and gives a new insight into the design and fabrication of Z-scheme photocatalysts.