Surfactant-Modified CdS/CdCO Composite Photocatalyst Morphology Enhances Visible-Light-Driven Cr(VI) Reduction Performance.

The surfactant modification of catalyst morphology is considered as an effective method to improve photocatalytic performance. In this work, the visible-light-driven composite photocatalyst was obtained by growing CdS nanoparticles in the cubic crystal structure of CdCO, which, after surfactant modification, led to the formation of CdCO elliptical spheres. This reasonable composite-structure-modification design effectively increased the specific surface area, fully exposing the catalytic-activity check point.

Prediction of thermodynamically stable Li-B compounds at ambient pressure.

To clarify controversial structures and phase stability in the Li-B system, we predicted energetically favorable compounds and crystal structures of the Li-B binary system at ambient pressure, mainly including LiB, LiB, and LiB, from ab initio evolutionary structure simulations and further investigated physical properties of stable Li-B compounds using first-principles methods. Metallic LiB, predicted in our simulations, has trigonal symmetry with space group R32 and contains linear B chains, but its superconducting T is low according to the electron-phonon coupling calculations. Orthorhombic LiB (Pnma) and tetragonal LiB (P4/mbm) are zero-gap semiconductors; LiB is a Dirac semimetal, and both LiB and LiB are promising thermoelectric materials.

Diverse Chemistry of Stable Hydronitrogens, and Implications for Planetary and Materials Sciences.

Nitrogen hydrides, e.g., ammonia (NH3), hydrazine (N2H4) and hydrazoic acid (HN3), are compounds of great fundamental and applied importance.

BaC: a thermodynamically stable layered superconductor.

To predict all stable compounds in the Ba-C system, we perform a comprehensive study using first-principles variable-composition evolutionary algorithm USPEX. We find that at 0 K the well-known compound BaC2 is metastable in the whole pressure range 0-40 GPa, while intercalated graphite phase BaC6 is stable at 0-19 GPa. A hitherto unknown layered orthorhombic Pbam phase of BaC has structure consisting of alternating layers of Ba atoms and layers of stoichiometry Ba2C3 containing linear C3 groups and is predicted to be stable in the pressure range 3-32 GPa.

Pressure-induced stabilization and insulator-superconductor transition of BH.

Diborane (B(2)H(6)), a high energy density material, was believed to be stable in a wide P, T interval. A systematic investigation of the B-H system using the ab initio variable-composition evolutionary simulations shows that boron monohydride (BH) is thermodynamically stable and can coexist with solid B, H(2), and B(2)H(6) in a wide pressure range above 50 GPa. B(2)H(6) becomes unstable and decomposes into the Ibam phase of BH and H(2) (C2/c) at 153 GPa.

Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations.

The stable crystal structure of LiBeH(3) is predicted on the basis of ab initio total-energy calculations using density-functional theory and an extended database of candidate structures and using global optimizations based on an evolutionary algorithm. At the level of density-functional theory, a CaSiO(3)_1-type structure with space group P2(1)/c, containing BeH(4) tetrahedra linked in chains, is the ground-state structure of LiBeH(3) (alpha-LiBeH(3)). It is found to be lower in energy than the structures proposed in previous studies.