Density functional theory and experimental studies of caffeic acid adsorption on zinc oxide and titanium dioxide nanoparticles

RSC Advances ◽  
2015 ◽  
Vol 5 (129) ◽  
pp. 106877-106885 ◽  
Author(s):  
Tianshi Zhang ◽  
Patrick Wojtal ◽  
Oleg Rubel ◽  
Igor Zhitomirsky

The outstanding adsorption properties of proteins, containing catecholic amino acid, 1,3,4-dihydroxyphenylalanine, and recent advances in nanoparticle functionalization using catecholates have generated interest in catecholate adsorption.

2017 ◽  
Vol 10 (13) ◽  
pp. 1-6 ◽  
Author(s):  
Fatemeh Amiri ◽  
Fatemeh Foroutan ◽  
Mir Masumeh Amiri ◽  
Hossein Asghar Rahnamaye Aliabad ◽  
◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Malihe Zeraati ◽  
Ali Mohammadi ◽  
Somayeh Vafaei ◽  
Narendra Pal Singh Chauhan ◽  
Ghasem Sargazi

In this paper, we have reported an innovative greener method for developing copper-metal organic frameworks (Cu-MOFs) using caffeic acid (CA) as a linker extracted from Satureja hortensis using ultrasonic bath. The density functional theory is used to discuss the Cu-MOF-binding reaction mechanism. In order to achieve a discrepancy between the energy levels of the interactive precursor orbitals, the molecules have been optimized using the B3LYP/6–31G method. The Taguchi method was used to optimize the key parameters for the synthesis of Cu-MOF. FT-IR, XRD, nitrogen adsorption, and SEM analyses are used to characterize it. The adsorption/desorption and SEM analyses suggested that Cu-MOF has a larger surface area of 284.94 m2/g with high porosity. Cu-MOF has shown anticancer activities against the human breast cancer (MDA-MB-468) cell lines, and it could be a potent candidate for clinical applications.


2017 ◽  
Vol 19 (3) ◽  
pp. 1896-1908 ◽  
Author(s):  
H. Tavassoli Larijani ◽  
M. Jahanshahi ◽  
M. Darvish Ganji ◽  
M. H. Kiani

In the present work, the adsorption of glycine amino acid and its zwitterionic form onto three different hexagonal sheets, namely graphene, boron-nitride (h-BN) and silicon carbide (h-SiC), has been investigated within the framework of density functional theory (DFT) calculations.


2019 ◽  
Vol 43 (12) ◽  
pp. 4900-4907 ◽  
Author(s):  
Dongzhi Zhang ◽  
Maosong Pang ◽  
Junfeng Wu ◽  
Yuhua Cao

A high-performance sulfur dioxide sensor based on a platinum-loaded titanium dioxide/molybdenum disulfide ternary nanocomposite is synthesized via layer-by-layer self-assembly.


Computation ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 52
Author(s):  
Jerwin Jay E. Taping ◽  
Junie B. Billones ◽  
Voltaire G. Organo

Nickel(II) complexes of mono-functionalized pyridine-tetraazamacrocycles (PyMACs) are a new class of catalysts that possess promising activity similar to biological peroxidases. Experimental studies with ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), substrate) and H2O2 (oxidant) proposed that hydrogen-bonding and proton-transfer reactions facilitated by their pendant arm were responsible for their catalytic activity. In this work, density functional theory calculations were performed to unravel the influence of pendant arm functionalization on the catalytic performance of Ni(II)–PyMACs. Generated frontier orbitals suggested that Ni(II)–PyMACs activate H2O2 by satisfying two requirements: (1) the deprotonation of H2O2 to form the highly nucleophilic HOO−, and (2) the generation of low-spin, singlet state Ni(II)–PyMACs to allow the binding of HOO−. COSMO solvation-based energies revealed that the O–O Ni(II)–hydroperoxo bond, regardless of pendant arm type, ruptures favorably via heterolysis to produce high-spin (S = 1) [(L)Ni3+–O·]2+ and HO−. Aqueous solvation was found crucial in the stabilization of charged species, thereby favoring the heterolytic process over homolytic. The redox reaction of [(L)Ni3+–O·]2+ with ABTS obeyed a 1:2 stoichiometric ratio, followed by proton transfer to produce the final intermediate. The regeneration of Ni(II)–PyMACs at the final step involved the liberation of HO−, which was highly favorable when protons were readily available or when the pKa of the pendant arm was low.


Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 150-164 ◽  
Author(s):  
B. Durbeej ◽  
L.A. Eriksson

Summary Density functional theory methods are utilized to investigate structural features and stabilities of the most common lignin dimerization products. It is found that intra-molecular hydrogen bonding acts as a stabilizing force in the lowest-energy conformer(s) of several different dimeric lignin structures. Furthermore, the calculations show that the hypothesis of thermodynamic control of monolignol dimerization accounts for some of the results obtained in experimental studies aimed at determining the ratios of intermonomeric linkages. A quantitative correlation between experimentally observed ratios and calculated relative energies cannot, however, be pointed out.


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