Enhancing the Photocatalytic Performance of Commercial TiO₂ Crystals by Coupling with Trace Narrow-Band-Gap Ag₂CO₃

Abstract

Trace Ag 2 CO 3 (0.5%, 1%, 2%, and 4%) was loaded on commercial TiO 2 crystals by a facile precipitation method. The obtained Ag 2 CO 3 /TiO 2 composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), photolimunescence (PL) spectroscopy, and UV−vis diffuse reflectance spectroscopy (DRS). Under UV light (λ = 254 nm) or visible light irradiation, the photocatalytic performance of the samples was tested in degradation of methyl orange (MO). Results showed that loading of 1 wt % Ag 2 CO 3 results in the best photocatalytic activity. Under UV or visible light irradiation, the degradation activity of 1%Ag 2 CO 3 /TiO 2 composite is 6 times that of TiO 2 and 4 times that of Ag 2 CO 3 or 3.4 times that of TiO 2 and 1.7 times that of Ag 2 CO 3 . Reasons for enhanced activity were found that the coupling of Ag 2 CO 3 promoted the visible light absorption and suppressed the recombination rate of e − /h + pairs. Moreover, more surface OH groups over the Ag 2 CO 3 /TiO 2 composite can react with the photogenerated h + and produce • OH radicals to decompose the dye.

Consideration of roles of commercial TiO2 pigments in aromatic polyurethane coating via the photodegradation of dimethyl toluene-2,4-dicarbamate in non-aqueous solution

“…All samples except P2 have bands at 1,080 cm -1 and 1,600 cm -1 which are the characteristics of SiO 2 and Al 2 O 3 , respectively [26]. The broader band at 3,460 cm -1 is attributed to the stretching vibration and bending vibration of hydroxyl groups on TiO 2 [27,28]. Another peak at 1,630 cm -1 is attributed to the bending vibration of H-O-H on absorbed water [29].…”

“…At the beginning of photocatalytic degradation reaction induced by TiO 2 particles, the photogenerated holes (h ? ) would oxidize hydroxyl groups or the water molecules absorbed on TiO 2 surface to ÁOH radicals [28]. ÁOH radicals are believed to be highly reactive in the decomposition of organic molecules.…”

Ag2CO3/UiO-66(Zr) composite with enhanced visible-light promoted photocatalytic activity for dye degradation

“…In spite of the good photocatalytic activity of pristine Ag 2 CO 3 [8][9][10], most of the studies were focusing on diverse substrates supported Ag 2 CO 3 as photocatalysts for water treatment [11][12][13][14].…”

Photocatalytic degradation and antibacterial investigation of nano synthesized Ag3VO4particles @PAN nanofibers

“…The energy-dispersive X-ray spectroscopy (EDX) spectrum of the PAN/Ag 3 VO 4 composite nanofibers was also recorded with the same FE-SEM instrument. High resolution images of different nanoparticles were obtained via transmission In recent years, silver containing compounds have garnered interest in the field of semiconductor photocatalysis due to their promising highly-efficient photocatalytic and antibacterial effects [23][24][25][26]. Moreover, for these Ag-containing photocatalysts, the top of their valence band (VB) consists of hybridized Ag 4d and O 2p orbitals.…”