Ionic liquid-assisted construction of Z-scheme Ag/Ag3PO4/Ag2MoO4 heterojunctions with enhanced photocatalytic performance

In this work, nanoflower-like Ag/Ag3PO4/Ag2MoO4 heterojunctions were in-situ constructed by a facile hydrothermal method in the presence of the ionic liquid 1-ethyl-3-methylimidazolium dihydrogen phosphate ([EMIm] H2PO4). [EMIm]H2PO4 can provide P source and affect the crystal growth. The formation of Ag/Ag3PO4/ Ag2MoO4 heterojunctions was confirmed by X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Light response ability of the photocatalyst and the separation efficiency of photogenerated carriers were analyzed by a UV-Vis spectrophotometer and a surface photovoltage spectrometer (SPS), respectively. Photocatalytic activity of the photocatalysts was investigated by destruction of methyl orange (MO) under simulated sunlight irradiation. The experimental results reveal that the photocatalytic performance of Ag/ Ag3PO4 /Ag2MoO4 heterojunctions is about 1.11 times higher than that of the bare Ag2MoO4. The enhanced photocatalytic performance is attributable to the larger specific surface area and the efficient separation of photoinduced charge carriers. The SPR effect of metallic Ag0 promotes the generation of center dot O2-. A Z-scheme photoinduced carriers separation mechanism was proposed according to all the characterization results.