Investigation of performance of aluminum doped carbon nanotube (8, 0) as adequate catalyst to oxygen reduction reaction.

The discovery of novel nano-catalysts to oxygen reduction reaction with high performance due to various application of fuel cells is very important. In present study the potential of aluminum doped carbon nanotube (8, 0) to oxygen reduction reaction in acidic condition was examined through theoretical models. The possible paths to oxygen reduction reaction on Al2-CNT (8, 0) surfaces were investigated and optimal path was identified from thermodynamic standpoint. Results indicated that the Al2-CNT (8, 0) catalyzed the oxygen reduction reaction through the Eley-Rideal and Langmuir-Hinshelwood mechanisms. The Al2-CNT (8, 0) catalyst has much better methanol and CO tolerance than platinum-based catalysts. In this study, the overpotential value of oxygen reduction reaction on aluminum doped carbon nanotube (8, 0) surface (ca 0.38 V) is lower than corresponding values on platinum-based catalysts (ca 0.45 V). Finally, results demonstrated that the Al2-CNT (8, 0) can be proposed as efficiency catalyst to oxygen reduction reaction.

Theoretical investigation of oxidation of NO (NO + ½ O2 → NO2) on surfaces of nickel-doped nanocages (Ni-C60 and Ni-B30N30).

In present study, the NO oxidation on Ni-carbon nanocage and Ni-boron nitride nanocage surfaces was investigated. The Ni-C60 and Ni-B30N30 catalysts can oxidize the NO molecule by Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms. In this study, the NO molecule was joined to Ni atom of the Ni-surface-O2* and Ni-surface-O* to generate the intermediates with low barrier energies. It can be concluded that the cis-Ni-surface-ONOO* complex in the ER pathway is more stable than four-elements-ring complex in LH pathway ca 0.06 and 0.08 eV, respectively. In the LH pathway, the studied catalysts were deactivated by irreversible absorption of NO2 molecules in Ni atoms of Ni-C60 and Ni-B30N30. In contrast, in the ER pathway two NO2 molecules were released in the normal temperature. In this study, the abilities of the Ni-C60 and Ni-B30N30 to oxidation of NO molecule was demonstrated. Finally, the systematic scheme to design of metal-doped nano-catalysts to oxidation of toxic gases was proposed.

Theoretical investigation of the ORR on boron-silicon nanotubes (B-SiNTs) as acceptable catalysts in fuel cells.

Here, the potential of boron doped silicon nanotubes (7, 0) as ORR catalysts is examined. Acceptable paths for the ORR on studied catalysts are examined through DFT. The optimum mechanism of the ORR on the surface of B2-SiNT (7, 0) is shown. The ORR on the surface of B2-SiNTs (7, 0) can continue through LH and ER mechanisms. The calculated beginning voltage for the ORR on B2-SiNTs (7, 0) is 0.37 V and it is smaller than the beginning voltage (0.45 V) for platinum-based catalysts. In the acidic solution the beginning voltage for the oxygen reduction process can be evaluated to be 0.97 V, which corresponds to 0.37 V as a minimum overvoltage for the ORR. The B2-SiNTs (7, 0) are suggested as an ORR catalyst in acidic environments.

Theoretical Study of Ability of Boron Nitride Nanocone to Oxidation of Sulfur Monoxide.

In recent years, the discovery of suitable catalyst to oxidation of sulfur monoxide (SO) in normal temperature is a major concern in the industry. In this study, in first step; the boron nitride nanocone (BNNC) with Ge were doped and the surface of Ge-BNNC by using of the O2 molecule were activated. In second step; oxidation of SO on surface of Ge-BNNC through the Langmuir Hinshelwood (LH) and Eley Rideal (ER) mechanisms was investigated. Calculated data reveal that surface of O2-Ge-BNNC oxide the SO molecule with Ge-BNNC-O-O* + SO → Ge-BNNC-O-O*-SO → Ge-BNNC-O* + SO2 and Ge-BNNC-O* + SO → Ge-BNNC + SO2 reactions. It can be concluded, the energy barrier of LH mechanism to oxidation of SO on Ge-BNNC is lower than ER mechanism. Finally, the Ge-BNNC is acceptable catalyst with low price and high performance to oxidation of SO in normal temperature.

Possibility of C38 and Si19Ge19 Nanocages in Anode of Metal Ion Batteries: Computational Examination.

In this study, the potential of C38 and Si19Ge19 as anode electrodes of Li-ion, Na-ion and K-ion batteries via density functional theory was investigated. Obtained results showed that Si19Ge19 as anode electrode in metal-ion batteries has higher potential than C38 ca 0.18 V. Calculated results illustrated that K-ion battery has higher cell voltage and higher performance than Li-ion and Na-ion batteries ca 0.15 and 0.31 V, respectively. Results showed that halogen adoption increased the cell voltage of studied metal-ion batteries ca 1.5-2.2 V. Results show that, Vcell values of studied metal-ion batteries in water are higher than gas phase ca 0.46 V. Finally it can be concluded that F-doped Si18Ge19 as anode electrode in K-ion battery has the highest performance and it can be proposed as novel metal-ion batteries with high performance.

The Cl Functionalized Aluminum Nitride (AlN) and Aluminum Phosphide (AlP) Nanocone Sheets as Hydrogen Selenide (H2Se) Sensor: a Density Functional Investigation.

The adsorption of H2Se molecule on AlN-NCS and AlP-NCS surfaces were investigated by using of DFT calculations. The potentials of Cl-functionalized AlN-NCS and AlP-NCS for H2Se adsorption were examined. All processes of H2Se-adsorption on considered nanocone sheets were exothermic reactions. The calculated |Ead| amount of complex H2Se with AlP-NCS was higher than AlN-NCS. The functionalization of considered nanocone sheets with Cl atom increase |Ead| amount of H2Se. Results reveal that, obtained Ead amounts of considered nanocone sheets have linear relationships with corresponding orbital energy amounts. Finally, the novel nanocone sheets with higher efficiency to adsorption of H2Se can be proposed.

Theoretical investigation of the use of nanocages with an adsorbed halogen atom as anode materials in metal-ion batteries.

The applicability of C44, B22N22, Ge44, and Al22P22 nanocages, as well as variants of those nanocages with an adsorbed halogen atom, as high-performance anode materials in Li-ion, Na-ion, and K-ion batteries was investigated theoretically via density functional theory. The results obtained indicate that, among the nanocages with no adsorbed halogen atom, Al22P22 would be the best candidate for a novel anode material for use in metal-ion batteries. Calculations also suggest that K-ion batteries which utilize these nanocages as anode materials would give better performance and would yield higher cell voltages than the corresponding Li-ion and Na-ion batteries with nanocage-based anodes. Also, the results for the nanocages with an adsorbed halogen atom imply that employing them as anode materials would lead to higher cell voltages and better metal-ion battery performance than if the nanocages with no adsorbed halogen atom were to be used as anode materials instead. Results further implied that nanocages with an adsorbed F atom would give higher cell voltages and better battery performance than nanocages with an adsorbed Cl or Br atom. We were ultimately able to conclude that a K-ion battery that utilized Al21P22 with an adsorbed F atom as its anode material would afford the best metal-ion battery performance; we therefore propose this as a novel highly efficient metal-ion battery. Graphical abstract The results of a theoretical investigation indicated that Al22P22 is a better candidate for a high-performance anode material in metal-ion batteries than Ge44 is. Calculations also showed that K-ion batteries with nanocage-based anodes would produce higher cell voltages and perform better than the equivalent Li-ion and Na-ion batteries with nanocage-based anodes, and that anodes based on nanocages with an adsorbed F atom would perform better than anodes based on nanocages with an adsorbed Cl or Br atom.

Antioxidant activity of omega-3 derivatives and their delivery via nanocages and nanocones: DFT and experimental in vivo investigation.

The antioxidant properties of omega-3 were investigated via experimental in vivo and theoretical methods. For experimental evaluation, oxidative stress was induced by 30 min bilateral renal ischemia and 24 h of reperfusion in male Sprague Dawley rats. The oxidative stress was evaluated through measuring malondialdehyde (MDA) and ferric reducing/antioxidant power (FRAP) levels in renal tissue. In theoretical methods, the reaction enthalpies of antioxidant mechanisms of omega-3 were calculated and the effects of NHMe, OMe, OH, Cl, and Me substituents on its antioxidant activity were investigated. Moreover, the omega-3 delivery potential by carbon and boron nitride nanocages and naocones were evaluated. The experimental results showed that omega-3 administration decreases MDA and increases FRAP levels after their changes by ischemia/reperfusion. Theoretical results indicated that NHMe and OMe substituents can significantly improve the antioxidant activity of omega-3. Also, boron nitride nanocone (BNNC) has higher |∆Ead| values, so it has higher potential for omega-3 delivery. Taken together, the new findings presented here indicate that omega-3 has anti-oxidative properties and NHMe and OMe substituents can improve its antioxidant activity. Moreover, adsorption of omega-3 on the surface of the studied nanostructures was exothermic, and BNNC with higher |∆Ead| values has higher potential for omega-3 delivery. Graphical abstract The interaction and adsorption of BNNC with omega-3 is exothermic and experimentally possible from the energetic viewpoint, so the BNNC with higher |∆Ead| and |∆Gad| values has higher potential for omega-3 delivery.

Theoretical and Experimental in vivo Study of Antioxidant Activity of Crocin in Order to Propose Novel Derivatives with Higher Antioxidant Activity and Their Delivery via Nanotubes and Nanocones.

In this study, the antioxidant activity of crocin via experimental and theoretical methods was investigated. In order to induce oxidative stress, 30-min renal ischemia and 24-h reperfusion were used in male Wistar rats. Oxidative stress was assessed by measuring tissue malondialdehyde (MDA) and ferric reducing/antioxidant power (FRAP). The results showed that following ischemia/reperfusion, the level of MDA was increased and FRAP decreased. Both of these changes were alleviated by crocin administration. The bond dissociation enthalpy and ionization potential values as enthalpies of mechanism of antioxidant activity of crocin were calculated by density functional theory method. According to obtained results, the novel structures of crocin with higher antioxidant activity for synthesis were proposed. Results indicated that NH2, OMe, and F substituents can improve the antioxidant activity of crocin. The crocin delivery via carbon and boron nitride nanotubes and nanocones was investigated. The results confirm that the calculated adsorption and free Gibbs energies of crocin on the surface of studied nanostructures were negative meaningfully, so these processes were exothermic and experimentally possible from the energetic viewpoint.

Computational Investigation of the Dissociative Adsorption of Dichloroacetylene (C2Cl2) on N Functionalized Carbon and Carbon Germanium (CGe) Nanocone Sheets in the Gas Phase and Dimethyl Sulfoxide.

The possibility of dichloroacetylene-sensing on carbon nanocone sheet and carbon germanium nanocone sheet surfaces has been investigated. The effects of nitrogen functionalization and dimethyl sulfoxide on the adsorption of dichloroacetylene gas on carbon nanocone sheet and carbon germanium nanocone sheet surfaces were investigated. Results reveal that adsorption of dichloroacetylene on studied nanocone sheets were exothermic. Results show that, adsorption energy value of dichloroacetylene on carbon germanium nanocone sheet surface were more negative than corresponding values of carbon nanocone sheet. Results reveal that, N functionalization and dimethyl sulfoxide, increase and decrease the absolute adsorption energy value of dichloroacetylene on studied nanocone sheets, respectively. These results show that, there were good linearity dependencies between adsorption energy and orbital energy values of studied nanocone sheets.

A theoretical study on the enthalpies of homolytic and heterolytic N-H bond cleavage in substituted melatonins in the gas-phase and aqueous solution.

In this paper, the study of melatonin and 60 meta- and ortho-substituted melatonins is presented. The reaction enthalpies related to the hydrogen atom transfer (HAT), single electron transfer - proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) have been calculated using DFT/B3LYP method in gas-phase and water. Results show that electron-withdrawing substituents increase the bond dissociation enthalpy (BDE), ionization potential (IP) and electron transfer enthalpy (ETE), while electron-donating ones cause a rise in the proton dissociation enthalpy (PDE) and proton affinity (PA). In ortho position, substituents show larger effect on reaction enthalpies than in meta position. In comparison to gas-phase, water attenuates the substituent effect on all reaction enthalpies. Results show that IP and BDE values can be successfully correlated with the indolic N-H bond length after electron abstraction, R(N-H(+*)), and the partial charge on the indolyl radical nitrogen atom, q(N). Furthermore, calculated IP and PA values for meta and ortho substituted melatonins show linear dependence on the energy of the highest occupied molecular orbital (E(HOMO)) of studied molecules in the two environments. SPLET represents the thermodynamically preferred mechanism in water.