A Theoretical Study of H2S Toxic Gas Adsorption on Pristine and Doped Monolayer (AlN)21 Using Density Functional Theory

The interactions between  graphene - like aluminium nitride P(AlN)21 nano ribbons doped and defect (AlN)21Sheet, P(AlN)21, (AlN)20-C,(AlN)19–C2, (AlN)20 –B,(AlN)19 –B2, D-P(AlN)20, D-(AlN)19 –C, D- (AlN)18 –C2, D-(AlN)19 –B, D-  (AlN)18 –B2), molecules and small toxic gas molecules ( H2S), were built for two different adsorption sites on graphene like aluminum nitride P(AlN)21, have been done by employing B3LYP density functional theory (DFT) with 6-31G(d,p) using Gaussian viw5.08 package of programs and Nanotube Modeller program(2018), The most stable adsorption configurations, adsorption energies, charge transfers (total Mulliken charge), electronic and band structures are calculated to deeply understand to find the sensitivity of all studied sheets for toxic gas H2S. In this research we got the adsorptions of H2S on P(AlN)21 , (C) atoms-doped P(AL-N)20 sheet, D-P(Al-N)20 , D-(C)atoms-doped (Al-N)19 and D-(B) atoms-doped(Al-N)19, (on atom) with an Ead (-0.468eV ),( -0.473 eV),(-0.457 eV), (-0.478 eV) and (-0.454 eV)  respectively, (Ead)of H2S on the center ring of the P(AL-N)21 , (C) atoms-doped (Al-N)20 sheet, D-P(Al-N)20 and D-(C, B)atoms-doped (AL-N)19 sheet are (-0.280 eV ),( -0.465 eV ), (-0.405 eV), (-0.468 eV) and -0.282 eV) respectively, are weak physisorption, on the other hand, P(AlN)21 could be a good sensor for H2S. However, the adsorptions of H2S, on the ((AlN)20 –B, (on atom N and center ring the sheet) are strong chemisorption because the Ead larger than -0.5 eV, due to the strong interaction, the ((AlN)20 –B, could catalyst or activate,  through the results that we obtained, which are the improvement of the sheet P(AlN)21 by doping and performing a defect in, it that can be used to design sensors

Formation Of Fe, Pt And (Pt@Fe) Ultra Fine Metal Nanoparticles In Different Solution Polarity Prepared By Nd-Yag Pulsed Laser

Iron (Fe), platinum (Pt) and (Pt@Fe) ultra fine (UF) nanoparticles (NPs) were synthesized by pulsed (Q-switched, 1064 doubled frequency-Nd:YAG). The laser ablation of Fe and Pt metal plates has been performed by immersing these metal plates in deionised water (DDW), ethanol alcohol and PVP polymer solvent. The pulsed laser ablation in liquids (PLAL) process preformed with 100 pulse energy of 700 mJ and liquid depth is 5 mm. The formation efficiency of PLAL process was quantified in term of the absorption spectrum peaks. The absorption spectra Iron (Fe/FeO, Pt) in DDW shows a sharp and single peak around 280, 234 nm, respectively, indicates the production of pure and spherical Fe/FeO, Pt (UF) NPs with an average size in the range of (2-5) nm. There is a simultaneous possibility of on-line observation of the nanoparticles formation via measuring the variation in nanoparticles absorption at the peaks observed. Changing the way of the fluid environment is a simple and flexible way to control the size appropriation and strength of Fe and Pt and bimetals (Pt@Fe) colloidal nanoparticles

Density functional theory study on the conformational behaviour of substituted banana-shaped mesogens with a central 1,3-phenylene unit

In the present study, the influence of the direction of ester linkage groups on the structural and electronic properties of the three-ring bent-core, bis(4-subst.-phenyl) 2-methyl-iso-phthalates molecules with a central 1,3-phenylene unit including 4-n-alkanoyl, 4-n-alkaoxyl and 4-n-alkayl terminal chains have been studied by density functional theory (DFT) calculations. The BP86/SVP level of theory has been adopted for all the computations. These computations were performed on the conformational behavior of the three-ring bent-core compounds in a systematic way. The relaxed rotation barrier with respect to the torsion angles φ1and φ2 where calculated. Moreover, replacement of terminal chains, alkanyl group by alkayloxy and alkayl groups, results a small rotational barrier with a difference of about 0.2-0.8 kcal.mol-1 in the height of the barriers, suggesting that the terminal chain have no effect on the relaxed barriers for these isomers. The dipole moment with respect to the torsion angle φ1 was also studied. The large differences in the dipole moments, can be seen as signs of their different phase behaviour and mesophase stability.