Ultrathin structure of oxygen doped carbon nitride for efficient CO2 photocatalytic reduction

Photocatalytic conversion of carbon dioxide into fuels and valuable chemicals is a promising method for carbon neutralization and solving environmental problems. Through a simple thermal-oxidative exfoliated method, the O element was doped while exfoliated bulk g-C3N4 into ultrathin structure g-C3N4. Benefitting from the ultrathin structure of g-C3N4, the larger surface area and shorter electrons migration distance effectively improve the CO2 reduction efficiency. In addition, density functional theory computation proves that O element doping introduces new impurity energy levels, which making electrons easier to be excited. The prepared photocatalyst reduction of CO2 to CO (116 μmol g−1 h−1) and CH4 (47 μmol g−1 h−1).

Homogeneous cobalt-catalyzed reductive amination for synthesis of functionalized primary amines

The development of earth abundant 3d metal-based catalysts continues to be an important goal of chemical research. In particular, the design of base metal complexes for reductive amination to produce primary amines remains as challenging. Here, we report the combination of cobalt and linear-triphos (bis(2-diphenylphosphinoethyl)phenylphosphine) as the molecularly-defined non-noble metal catalyst for the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds, gaseous ammonia and hydrogen in good to excellent yields. Noteworthy, this cobalt catalyst exhibits high selectivity and as a result the -NH2 moiety is introduced in functionalized and structurally diverse molecules. An inner-sphere mechanism on the basis of the mono-cationic [triphos-CoH]+ complex as active catalyst is proposed and supported with density functional theory computation on the doublet state potential free energy surface and H2 metathesis is found as the rate-determining step.

New carbon allotropes with metallic conducting properties: a first-principles prediction

Combining density functional theory computation and the global minimum structural search, we have found new α-, β-, and δ-phographene carbon allotropes.