Hydrogen phosphate anions modified hydrogen titanate nanotubes for methylene blue adsorption from aqueous solution: Validating novel method of predicting adsorption capacity. Issue 1 (March 2016)

• Record Type: Journal Article
• Authors: Jose, Manu; Harsha, N.; Suhailath, K.; Mohamed, A. Peer; Shukla, Satyajit
• Is Part Of: Journal of environmental chemical engineering. Volume 4:Issue 1(2016:Mar.)
• Page Start: 1295
• Page End: 1307
• Publication Date: 2016-03
• Subjects: Adsorption -- Advanced oxidation process -- Hydrogen peroxide -- Kinetics -- Equilibrium isotherm -- Methylene blue; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2016.01.042
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Highlights: TiP2 O7 /PO4 3− ions modified nano-size anatase TiO2 is synthesized via sol–gel. HPO4 2− anions modified H2 Ti3 O7 nanotubes (HP-HTN) are processed via hydrothermal. HP-HTN exhibit methylene blue adsorption capacity of 139 mg g −1 (solution-pH 10). Maximum dye-decomposition rate-capacity is determined at [H2 O2 ] of 3 and 15 wt%. Obtained data supports the novel method of prediction of dye-adsorption capacity. Abstract: A new method for predicting the adsorption capacity of pure hydrogen titanate (H2 Ti3 O7 ) nanotubes (HTN) via one-step dye-removal method of chemically-activated catalytic process conducted in the dark has been recently demonstrated. In this work, hydrogen phosphate anions (HPO4 2− ) modified H2 Ti3 O7 nanotubes (HP-HTN) have been synthesized via the hydrothermal treatment of sol–gel derived titanyl phosphate (TiP2 O7 )/phosphate (PO4 3− ) ions modified nanocrystalline anatase-titania (TiO2 ). The methylene blue (MB) adsorption capacity of HP-HTN has been determined to be 139 mg g −1 which is higher than that (105–121 mg g −1 ) of pure HTN. It has been demonstrated that HP-HTN can decompose the MB dye in an aqueous solution via the hydrogen peroxide (H2 O2 ) activation. It is observed that the HP-HTN exhibit higher dye-decomposition rate-capacity compared with that of pure-HTN. The maximum MB dye-removal rate-capacity of 194 and 393 mg g −1 h −1 has been determined at the initial H2 O2 concentration of 3 and 15 wt%. The HP-HTN exhibit a perfect liner relationship (slope and regression correlation coefficient, < r 2 >, values of 17 mg g −1 h −1 wt% −1 and 0.999) between the maximum MB dye-removal rate-capacity as a function of initial H2 O2 concentration which strongly supports the new method for the prediction of adsorption capacity via the one-step dye-removal method of chemically-activated catalytic process conducted in the dark.