The Preparation of a Highly Efficient Ag3PO4/Ag/Bi2O2CO3 Photo-Catalyst and the Study of Its Photo-Catalytic Organic Synthesis Reaction Driven by Visible Light

Abstract

Ag 3 PO 4 /Ag/Bi 2 O 2 CO 3 composites were prepared by a hydrothermal and precipitation method. The morphology, structure, and valence state of the photo-catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface areas, and UV-vis diffuse reflectance spectra (UV-vis DRS). They were applied as heterogeneous catalysts in the synthesis of esters from aldehydes (or alcohols) and alcohols and the synthesis of imines from alcohols and amines under visible light irradiation. The photo-catalytic activities of the esterification reactions of aldehydes and alcohols were heavily dependent on the loading of Ag 3 PO 4 /Ag/Bi 2 O 2 CO 3 as well as the intensity and wavelength of the visible light. Furthermore, their conversion under visible light irradiation was superior to that in the dark. Herein a reaction mechanism from aldehydes and alcohols to esters was proposed, and the Ag 3 PO 4 /Ag/Bi 2 O 2 CO 3 catalysts could be used six times without a significant decrease in activity. Using these catalysts under visible light could motivate future studies to develop efficient recyclable photo-catalysts and facilitate many synthetic organic reactions.

Photoenergy Conversion Behaviors of Photoluminescence and Photocatalysis in Silver-Coated LiBaPO4:Eu2+

“…Parts c–f of Figure shows the absorption of Ag-coated phosphors; heavy background absorption was observed in the visible wavelength with an obvious red shift (∼100 nm). Usually the absorption of the localized surface plasmon resonance (SPR) of the Ag nanoparticles on an inorganic framework cold occur within the 400–800 nm with the most intensity in the near UV region. , For example, the SPR absorption peaks of Ag nanoparticles in Ag 3 PO 4 , Li 2 B 4 O 7 , phosphate glasses, and silicate glasses are 452, 415, 390, and 420 nm, respectively. This wavelength region overlaps with the absorption edge of LiBaPO 4 .…”