Increased Selectivity in Photolytic Activation of Nanoassemblies Compared to Thermal Activation in On-Surface Ullmann Coupling

On-surface synthesis is a powerful method that has emerged recently to fabricate a large variety of atomically precise nanomaterials on surfaces based on polymerization. It is very successful for thermally activated reactions within the framework of heterogeneous catalysis. As a result, it often lacks selectivity. We propose to use selective activation of specific bonds as … Read more

Breaking Continuously Packed Bimetallic Sites to Singly Dispersed on Nonmetallic Support for Efficient Hydrogen Production

We have synthesized Pt1Zn3/ZnO, also termed 0.01 wt %Pt/ZnO-O2–H2, as a catalyst containing singly dispersed single-atom bimetallic sites, also called a catalyst of singly dispersed bimetallic sites or a catalyst of isolated single-atom bimetallic sites. Its catalytic activity in partial oxidation of methanol to hydrogen at 290 °C is found to be 2–3 orders of … Read more

Anomalous isotope effect on the optical bandgap in a monolayer transition metal dichalcogenide semiconductor

Isotope effects have received increasing attention in materials science and engineering because altering isotopes directly affects phonons, which can affect both thermal properties and optoelectronic properties of conventional semiconductors. However, how isotopic mass affects the optoelectronic properties in 2D semiconductors remains unclear because of measurement uncertainties resulting from sample heterogeneities. Here, we report an anomalous … Read more

Mapping spin interactions from conductance peak splitting in Coulomb blockade

We investigate the transport properties of a quantum dot coupled to leads interacting with a multispin system using the generalized master equation within the Coulomb blockade regime. We find that if two states for each scattering region electron manifold are included, several signatures of the interacting spin system appear in steady-state transport properties. We provide a … Read more

A closer look at how symmetry constraints and the spin–orbit coupling shape the electronic structure of Bi (111)

Fully relativistic density-functional-theory calculations of Bi(111) thin films are analyzed to revisit their two metallic surface-states branches. We first contrast these metallic branches with surface states arising at gaps in the valence band opened by the spin–orbit coupling (SOC). We find that the two metallic branches along Γ𝑀― do not overlap with the bulk band at the … Read more

Off-lattice pattern recognition scheme for KMC simulations

We report the development of a pattern-recognition scheme for the off-lattice self-learning kinetic Monte Carlo (KMC) method, one that is simple and flexible enough that it can be applied to all types of surfaces. In this scheme, to uniquely identify the local environment and associated processes involving three-dimensional (3D) motion of an atom or atoms, … Read more

Selective oxidation of ammonia on RuO2(110)

We have used a combination of density functional theory (DFT) and kinetic Monte Carlo (KMC) simulations to calculate the reaction rates for the selective oxidation of ammonia on RuO2(110). Our KMC simulations of 18 reactions among NHx (x=0-3) and OHx (x=0-2) species on RuO2(110) show 93% selectivity for NO, in close agreement with experiment (~95%). The chief … Read more

Time-dependent density-matrix functional theory for biexcitonic phenomena

We formulate a time-dependent density-matrix functional theory (TDDMFT) approach for higher-order correlation effects like biexcitons in optical processes in solids based on a reduced two-particle density-matrix formalism within the normal orbital representation. A TDDMFT version of the Schrodinger equation for biexcitons in terms of one- and two-body reduced density matrices is derived, which leads to … Read more

Toward an Understanding of Ligand Selectivity in Nanocluster Synthesis

We performed scalar relativistic density functional theory (DFT) calculations using the projector augmented wave scheme (PAW) to examine the reactivity and selectivity of diphosphine ligands LM, with the formula PH2(CH2)MPH2 (spacer M = 3, 5), toward small-sized cationic Aun (n = 7-11) nanoclusters. By isolating the ligand-induced contribution to the stability condition, we show that such interaction … Read more