Mehvish Perveen

Bio: Mehvish Perveen is an academic researcher from University of Agriculture, Faisalabad. The author has contributed to research in topics: Chemistry & Density functional theory. The author has an hindex of 3, co-authored 6 publications receiving 22 citations.

Probing the Reactions of Thiourea (CH4N2S) with Metals (X = Au, Hf, Hg, Ir, Os, W, Pt, and Re) Anchored on Fullerene Surfaces (C59X)

Abstract: Upon various investigations conducted in search for a nanosensor material with the best sensing performance, the need to explore these materials cannot be overemphasized as materials associated with best sensing attributes are of vast interest to researchers. Hence, there is a need to investigate the adsorption performances of various metal-doped fullerene surfaces: C59Au, C59Hf, C59Hg, C59Ir, C59Os, C59Pt, C59Re, and C59W on thiourea [SC(NH2)2] molecule using first-principles density functional theory computation. Comparative adsorption study has been carried out on various adsorption models of four functionals, M06-2X, M062X-D3, PBE0-D3, and ωB97XD, and two double-hybrid (DH) functionals, DSDPBEP86 and PBE0DH, as reference at Gen/def2svp/LanL2DZ. The visual study of weak interactions such as quantum theory of atoms in molecule analysis and noncovalent interaction analysis has been invoked to ascertain these results, and hence we arrived at a conclusive scientific report. In all cases, the weak adsorption observed is best described as physisorption phenomena, and CH4N2S@C59Pt complex exhibits better sensing attributes than its studied counterparts in the interactions between thiourea molecule and transition metal-doped fullerene surfaces. Also, in the comparative adsorption study, DH density functionals show better performance in estimating the adsorption energies due to their reduced mean absolute deviation (MAD) and root-mean-square deviation (RMSD) values of (MAD = 1.0305, RMSD = 1.6277) and (MAD = 0.9965, RMSD = 1.6101) in DSDPBEP86 and PBE0DH, respectively.

Plasma-Induced Hierarchical Amorphous Carbon Nitride Nanostructure with Two N2C-Site Vacancies for Photocatalytic H2O2 Production

Abstract: Carbon nitride (CN) with nitrogen vacancy is a robust photocatalyst with proven enhancing H 2 O 2 production ability. However, nitrogen vacancy control is extremely challenging with the majority of reports representing it as a few vacancies. Herein, for the first time, the amorphous CN (ACN) with two N 2 C -site vacancies in one CN unit is prepared by a one-step H 2 plasma approach. First-principles calculations and experimental results provide consistent evidence that two N 2 C vacancies are located in one CN unit structure after amorphous transformation. Plasma-induced ACN is stable with a hierarchical continuous nanosheet network structure and exhibits an ultrahigh specific surface area of ~405.76 m 2 g −1 , which is 83 times higher than that of pristine CN (4.89 m 2 g −1 ) and significantly enhanced photocatalytic H 2 O 2 production, yielding 1874 μmolg −1 h −1 . Besides, the existence potential drop of 2.61 eV for the electrostatic potential in ACN is key to charge carrier separation. Moreover, the amorphous transformation leads to a new strong band tail, which remarkably enhances the absorbance edge of ACN up to 593 nm, resulting in a wider range of visible-light absorption to enhance H 2 O 2 production. The results have provided an effective approach for promoting the practical application of ACN in photocatalytic H 2 O 2 production. Upon the H 2 plasma treatment, the high energetic particles bombarded the N lattice sites of graphitic carbon nitride (GCN) to form an amorphous carbon nitride (ACN) with two N 2 C -site vacancies in one CN unit. The ACN with hierarchical nanostructure exhibits ultra-high specific surface area and photocatalytic activity. • We developed a one-step H 2 plasma treatment to induce hierarchical ACN nanostructure with two N 2 C -site vacancies in one unit of CN structure without element doping. • The plasma-induced ACN is stable with hierarchical continuous nanosheet network structure and exhibits ultrahigh specific surface area and significantly enhanced photocatalytic H 2 O 2 production yielding. • The two N 2 C vacancies in ACN nanostructure are determined by the first-principles calculations and the consistent electronic character of experimental results. • The amorphous transformation of CN leads to a new strong band tail, which remarkably enhances the absorbance edge of ACN up to 593 nm, resulting in a wider range of visible-light absorption.

Computational study on the interactions of functionalized C24NC (NC = C, -OH, -NH2, –COOH, and B) with chloroethylphenylbutanoic acid

Abstract: Computational chemistry approach based on density functional theory (DFT) was utilized to investigate the interaction, adsorption behaviour, electronic and structural properties of nanostructured complexes formed by4-(4-(bis(2-chloroethyl) amino) phenyl) butanoic acid (CPB) and all carbon fullerene nanocage, (C24NC), Boron functionalized carbon nanocage (C24NC@B@CPB), Carboxylate functionalized (C24NC@COOH@CPB), amino functionalized (C24NC@NH2@CPB) and hydroxy functionalized (C24NC@OH@CPB) nanostructured materials. To understand effectively the interaction of the drug and surface, topological analysis was conducted via the atoms in molecule (QTAIM) and NCI approach. Electronic properties such as quantum chemical descriptors, NBO and NLO are equally considered and reported. All computations were achieved at the B3LYP-D3 and ωB97XD levels of theory with the 6-311++G(d,p) basis set. The results indicate that the adsorption energy of CPB on C24NC and its functionalized derivatives are in the range of -0.52 to 2.89 eV indicating that physisorption and chemisorption mechanism are prevalent mechanisms of adsorption. C23B@CPB, C24OH@CPB, and C24NH2@CPB were observed to possess the best characteristics to be considered as transport vehicles for CPB due to their strong adsorption nature (chemisorption) and solubility in solution.