Ag2CO3-halloysite nanotubes composite with enhanced removal efficiency for water soluble dyes

Abstract

The release of water soluble dyes into the environment is an utmost concern in many countries. This paper presents the effects of Ag 2 CO 3 -halloysite composites on the efficient removal of water soluble dyes. In this study, NaHCO 3 solution was added dropwisely to halloysite nanotubes (HNTs) dispersed in aqueous AgNO 3 to form Ag 2 CO 3 -HNTs composite. The synthesized Ag 2 CO 3 -HNTs composite was characterized with Diffused Reflectance Spectroscopy (DRS), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDX) and Fourier Transform Infra-Red (FT-IR) spectroscopy. The photocatalytic activity and the adsorption capacity of Ag 2 CO 3 -HNTs on methylene blue and rhodamine b dyes were dependent on pH and the amount of HNTs used in the synthesis. The photodegradation efficiency of Ag 2 CO 3 was lower when compared with that of the composite material. This observation is due to the reduction in the electron-hole recombination with the HNTs acting as electron trapping site and the enhanced aqueous dispersity of Ag 2 CO 3 -HNTs. The enhanced adsorption of water soluble dyes by the Ag 2 CO 3 -HNTs resulted from the electrostatic attraction of cationic dyes to the surface of the HNTs (negatively charged). The Ag 2 CO 3 -HNTs therefore removed dye pollutants through a combination of photocatalytic and adsorption processes. The results obtained during the study confirmed the potential application of Ag 2 CO 3 -HNTs composite in water treatment technologies.

Photocatalytic Evaluation of Ag2CO3 for Ethylparaben Degradation in Different Water Matrices

“…Indeed, the pKa value of EP is 8.34 [4], while Ag 2 CO 3 has been reported to change surface charge under highly basic conditions [37]. These observations agree with M. Guo et al [37] and E. Nyankson et al [38] who studied the photocatalytic performance of AgBr/Ag 2 CO 3 and Ag 2 CO 3 -halloysite nanotubes respectively, showing the dependence of photocatalytic activity on pH, with favoring effects taking place under neutral and basic conditions.…”

WO3/Ag2CO3 Mixed Photocatalyst with Enhanced Photocatalytic Activity for Organic Dye Degradation

“…For the Ag 2 CO 3 sample, the diffraction peaks at 2θ values of 18.48° (020), 20.38° (110), 32.52° (−101), 33.60° (−130), 36.94° (200), 37.60° (040), 39.54° (031), 41.6° (220), 44.30° (131), 47.08° (230), 51.36° (150), and 56.08° (231) are in good agreement with monoclinic phase Ag 2 CO 3 (JCPDS No. 26-0399). , The XRD characteristic peaks of WO 3 in the mixed WO 3 /Ag 2 CO 3 samples are obvious, while the peaks of Ag 2 CO 3 are very weak. One possible reason may be that the content of Ag 2 CO 3 in the mixed samples is less than that of WO 3 .…”

“…Characterization. Figure 1 shows the XRD patterns of WO 33,44 The XRD characteristic peaks of WO 3 in the mixed WO 3 /Ag 2 CO 3 samples are obvious, while the peaks of Ag 2 CO 3 are very weak. One possible reason may be that the content of Ag 2 CO 3 in the mixed samples is less than that of WO 3 .…”

Reactive dye adsorption desorption and stamping by halloysite

“…These are very good results as it was thickened and as a consequence a hybrid with a high concentration of colorant and a good intensity of color. It is important to obtain a reference of the amount of color that is achieved with the printing process, for which a reflectance measurement has been used and the Kubelka-Munk theory (K/S) is taken as a reference, thanks to which You can define the values that quantify the light interaction circumstances that are none other than the light diffusion coefficient (S) and the light adsorption coefficient (K) (Nyankson et al, 2019). result of this analysis was carried out with the samples exposed to the normalized illuminant D65 in the visible wavelength range between 400 and 700 nm, which resulted in a maximum reflectance at 400 nm.…”