Iron phosphate, Fe2 (HPO4)3*4H2O, is synthesized at ambient temperature, using the inorganic sol–gel method coupled to the microwave route. The experimental conditions for the gelling of Fe (III)-H3PO4 system are previously defned. Potentiometric Time Titration (PTT) and Potentiometric Mass Titration (PMT) investigate the acid–base surface chemistry of obtained phosphate. Variations of surface charge with the contact time, Q a function of T, are examined for time contact varying in the range 0–72 h. The mass suspensions used for this purpose are 0.75, 1.25 and 2.5 g L−1 . The point of zero charge (PZC) and isoelectric point (IEP) are defned using the derivative method examining the variations dpH dt = f(pH), at lower contact time. A shift is observed for PZC and IEP towards low values that are found to be 2.2±0.2 and 1.8±0.1, respectively. In acidic conditions, the surface charge behavior of synthesized phosphate is dominated by > POH group which pKa=2.45±0.15. Q against T titration method is performed for synthesized Fe2 (HPO4)3*4H2O in NaCl electrolytes. The maximal surface charge (Q) is achieved at the low solid suspension. Hence, for m=0.75 g L−1 , Q value of 50 coulombs is carried at μ=0.1 and pH around 12, while charge value around 22 coulombs is reached in the pH range: 3–10. The efect of activation time, Q and pH on sodium insertion in iron phosphate, were fully evaluated. To determine the optimal conditions of the studied process, mathematical models are used develop response surfaces in order to characterize the most signifcant sodium interactions according to the variation of the pH, Q, the contact time and the contents of the synthesized material.

Title

BMC

Publisher

nature signiture

Publisher Country

United Kingdom

Indexing

Thomson Reuters

Impact Factor

2.1

Publication Type

Prtinted only

Volume

15

Year

2021

Pages

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