Physical chemistry
Mehdi Ghambarian; Zahra Azizi; Mohammad Ghashghaee
Volume 5, Issue 1, pp. 1-120, Serial No. 14 , January 2017, , Pages 28-34
Abstract
Density-functional-based and ab initio calculations were implemented at different computational levels to estimate the binding energy of Zn2+ ion adsorbed on the available sites of a silicate MEL-type adsorbent. B3LYP and MP2 were used in combination with the 6-31G*, 6-31+G*, LanL2DZ, 6-311+G*, and Def2-TZVP ...
Read More
Density-functional-based and ab initio calculations were implemented at different computational levels to estimate the binding energy of Zn2+ ion adsorbed on the available sites of a silicate MEL-type adsorbent. B3LYP and MP2 were used in combination with the 6-31G*, 6-31+G*, LanL2DZ, 6-311+G*, and Def2-TZVP basis sets. The zinc cation was found to preferentially occupy the 6MR sites followed by the cage-like positions. Nevertheles, all of the available sites exhibited negative amounts for the Gibbs free energy and enthalpy of adsorption with the corresponding population-averaged values of –160.84 and –169.53 kcal/mol at the B3LYP/Def2-TZVP level. Overall, the B3LYP/LanL2DZ method illustrated the highest deviation from the others both in trends and absolute values of binding energy. While the absolute binding energy ranged from 131.23 to 230.79 kcal/mol over different sites, the population-averaged binding energies altered from 146.08 to 162.54 kcal/mol depending on the method employed.
Analytical chemistry
Meysam Sadeghi; Sina Yekta
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 21-41
Abstract
In this work, the practicality of catalytic surfaces of nano-structured Co3O4 and MnCo2O4 for the adsorption and neutralization reactions of dimethyl methyl phosphonate (DMMP) as an toxic agricultural organo-phosphorous pesticide has been investigated. The Co3O4 and MnCo2O4 NPs have been successfully ...
Read More
In this work, the practicality of catalytic surfaces of nano-structured Co3O4 and MnCo2O4 for the adsorption and neutralization reactions of dimethyl methyl phosphonate (DMMP) as an toxic agricultural organo-phosphorous pesticide has been investigated. The Co3O4 and MnCo2O4 NPs have been successfully prepared by precipitation method using cobalt nitrate and manganese nitrate as the precursors and then characterized by SEM-EDX and XRD. The application of the synthesized nanoparticles as solid catalysts for the adsorption and neutralization of dimethyl methyl phosphonate (DMMP) was assayed in different solvents and monitored by 31PNMR and IR analyses. The experimental results have shown that 39%, 47% and 62% of DMMP have been adsorbed on the surface of Co3O4 nanoparticles in isopropanol, chloroform and decane solvents after 5 h, respectively. While, higher amounts (80%, 92% and 100%) were removed in the same solvents respectively, when MnCo2O4 nanoparticles were chosen as the catalytic surface. This demonstrates that the choice of nanoparticle and solvent (MnCo2O4 nanoparticles and decane) have a great impact on the neutralization of DMMP.