Study of Different Morphology of Zinc Hydroxide Salt as Adsorbent of Azo Dyes

Abstract

In this study, zinc layered hydroxide salts (Zn-LHS) intercalated with dodecyl sulfate (DDS) anion in nanocone morphology (LHS-NC) and conventional stone-like co-precipitation LHS phases (LHS-CO) were investigated as adsorbent of Orange G (OG) and Sunset Yellow (SY) dye. LHS-NC was prepared by urea hydrolysis method, while LHS-DDS was prepared by coprecipitation method. XRDP, FTIR, and SEM were used to characterize their structure and showed the formation of layered compounds with very well layered stacking with nanocone and conventional layer stone morphology. After OG and SY adsorption, the results (XRDP, FTIR, UV-Vis, Zetametry) showed that the Freundlich adsorption isotherms had been well fitted, and both OG and SY dyes were intercalated in interlayer space of LHS, where LHS-CO and LHS-NC present high uptake capability of SY dye remotion equal a 227.79 and 442.48 (mg g À 1 ) while OG adsorption capability were 2.52 and 6.39 (mg g À 1 ), respectively. For the kinetics study, the best fit was obtained by the pseudo-second-order model, whereas the results of intraparticle diffusion show a one-step adsorption process. Hence, this study demonstrated Zn-LHS in nanocone morphology, and conventional stone-like co-precipitation phase makes them potentially attractive adsorbents in water purification.

Adsorption Process of Methyl Orange Dye onto Zinc Hydroxide Nitrate: Kinetic and Thermodynamic Studies

“…The peak at 9.01 • corresponds to the crystalline structure with a basal distance of 9.64 Å. The basal distance was calculated according to the highest-order basal peak of the ZHN diffractogram, and the value is consistent with the ones found in the literature [23].…”

“…The peak at 9.01 • corresponds to the crystalline structure with a basal distance of 9.64 Å. The basal distance was calculated according to the highest-order basal peak of the ZHN diffractogram, and the value is consistent with the ones found in the literature[23].The X-ray diffractograms of the ZHN-MO samples at two different concentrations in Figure2b,c show a lower intensity of the peak at 9.01 • 2θ angle when compared to the ZHN peak, where the basal distance increased from 9.64 Å to 9.86 Å. The peaks at 7.33 • (002), 11.06 • (003) and 14.82 • (004) (tagged with * in Figure2b,c) correspond to a new phase present on ZHN-MO.…”