Confinement dependence of electro-catalysts for hydrogen evolution from water splitting

• Mikaela Lindgren and
• Itai Panas

Beilstein J. Nanotechnol. 2014, 5, 195–201, doi:10.3762/bjnano.5.21

• by Figure 1c. The line at −0.2 eV is owing to the increase in entropy when a water molecules H2O(l) is consumed (−70.0 Jmol−1K−1 [10]) and a H2(g) molecule is formed (130.7 Jmol−1K−1 [10]) at 298 K and 100 kPa (compare Equation 1), while neglecting changes in entropy in Zr upon oxidation. Thus, a

Fabrication of carbon nanomembranes by helium ion beam lithography

• Xianghui Zhang,
• Henning Vieker,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2014, 5, 188–194, doi:10.3762/bjnano.5.20

• associated with a conformational entropy reduction of a molecule after being cross-linked, as a single molecule is more flexible and thus possesses higher degrees of freedom compared to a molecule being cross-linked and constrained by covalent bonds. The sequence of cross-linking depends on the

The role of oxygen and water on molybdenum nanoclusters for electro catalytic ammonia production

• Jakob G. Howalt and
• Tejs Vegge

Beilstein J. Nanotechnol. 2014, 5, 111–120, doi:10.3762/bjnano.5.11

• approach. Molecular O2 is not expected to be present under operating conditions and the sole contributor of O atoms is water. At standard ambient temperature and pressure the adsorption energies are corrected with zero-point energy, EZPE, and entropy, TS, contributions at room temperatures. In this paper

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• solvation shell for the ions (Figure 7). As the temperature is subsequently increased, the minimum for the contact ion pairs and solvent-separated ion pairs becomes deeper. More importantly, the main contribution to the free energy of contact ion pairs seems to be dominated by the entropy gain, not the

• , the energy appears to weakly prevent the formation of ion pairs, while the entropy gain remains to be the main driving force for contact pairs. It is instructive to trace the temperature dependence of the energetic and entropic contributions for some specific interion separations, in particular, for

• presented above we can conclude that the change in ion association observed in the system is largely an entropic effect. Ion pairing, which takes place with decreasing temperature, leads to a decrease in entropy and to a corresponding increase in free energy for the entire system. One part of the

Size-dependent phase diagrams of metallic alloys: A Monte Carlo simulation study on order–disorder transitions in Pt–Rh nanoparticles

• Johan Pohl,
• Christian Stahl and
• Karsten Albe

Beilstein J. Nanotechnol. 2012, 3, 1–11, doi:10.3762/bjnano.3.1

• redeveloped on a more intuitive foundation [7] under the term “nanothermodynamics” [8] by the same author. Recent microcanonical approaches pioneered by Gross et al. [9][10] explore the topology of the entropy surface S(E,Ni) as a function of the energy E and the particle number N. Studying the entropy

• surface in the microcanonical ensemble can be a useful theoretical tool, because convex intruders of the entropy can be used as a concept to assign first-order transitions even in finite systems, and additional quantities, such as the interface tension between phases, become accessible [9]. A quantitative

• assessment of the entropy surface is in principle possible by the Wang–Landau algorithm [11] but a tedious task for a more complex Hamiltonian. Furthermore, the choice of the microcanonical ensemble corresponds to a completely isolated system, which does not exchange energy with its environment. Such

STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

• Tibor Kudernac,
• Natalia Shabelina,
• Wael Mamdouh,
• Sigurd Höger and
• Steven De Feyter

Beilstein J. Nanotechnol. 2011, 2, 674–680, doi:10.3762/bjnano.2.72

• backbone and thus decreases the probability of effective adsorption on the surface. In addition, upon adsorption of 2 the freedom of movement of the counterions will be restricted to one side of the molecule, thus decreasing the entropy. Uncharged macrocycle 1 on the other hand does not bear any charges or

Surface induced self-organization of comb-like macromolecules

• Konstantin I. Popov,
• Vladimir V. Palyulin,
• Martin Möller,
• Alexei R. Khokhlov and
• Igor I. Potemkin

Beilstein J. Nanotechnol. 2011, 2, 569–584, doi:10.3762/bjnano.2.61

• brush with symmetric distribution of the side chains will not be reconstructed, despite a penalty in the mixing entropy. It was found that the self-equilibration of 2D brushes results in their curvature [105][106][107][108][109]; the explanation was provided in the theoretical papers [107][108][109

• by the one obtained for the case of cylindrical micelles in the bulk [68]: Conformational entropy loss due to adsorption of the side chains comprises contributions from A and B units. The free energy of the B chains can be calculated as that of the chains placed in a slit of thickness h. Owing to the

Structural and magnetic properties of ternary Fe_1–xMn_xPt nanoalloys from first principles

• Markus E. Gruner and
• Peter Entel

Beilstein J. Nanotechnol. 2011, 2, 162–172, doi:10.3762/bjnano.2.20

• bulk calculations. This, however, is beyond the scope of the present work. Nevertheless, the fact that a magnetic field can induce a magnetized state, which, however, does not necessarily relate to a higher degree of magnetic order, i. e., a lower magnetic entropy, raises the hope that a suitably

• from Figure 3, the entropy change associated with the magnetic transition might become sizeable. As the changes in lattice parameter and c/a can be in the order of a few percent, it might also be worthwhile to explore in more detail, whether corresponding magnetic field induced structural changes can