Solar energy hydrogen production is one of the best solutions for energy crisis. Therefore, finding effective photocatalytic materials that are able to split water under the sunlight is a hot topic in the present research fields. In addition, theoretical prediction is a present low-cost important method to search a new kind of materials. Herein, with the aim of seeking efficient photocatalytic material we investigated the photocatalytic activity of GaAs monolayer by the first principles calculation. According to the obtained electronic and optical properties, we primarily predicted the photocatalytic water splitting activity of GaAs monolayer, which the result further confirmed by the calculated reaction free energy. More remarkably, predicted carrier mobility of GaAs monolayer 2838 cm2V−1s−1 is higher than 200 cm2V−1s−1 of MoS2. Our finding provides a promising material for the development of renewable energy conversion and a new outlook for better designing of a superior photocatalyst for water splitting.

Four new supertetrahedron-layered chalcogenides as the first example of exhibiting vertex-sharing T3-clusters in the known quaternary chalcogenides were discovered.

By the application of cation substitution, five new members of cyclophosphates, RbCdPO, CsPbPO, CsSrPO, RbMgPO, and RbCaPO, were obtained by a high-temperature melt method and structurally analyzed. The five compounds have identical stoichiometries, and all of them feature a three-dimensional network, which consists of MO (M = Cd, Mg, Ca, Pb, Sr) octahedra and cyclic PO units, while alkali-metal atoms are located within the network. However, RbCdPO and CsPbPO belong to the asymmetric space groups P6̅ c2 and Pna2, respectively, and the other three compounds belong to orthorhombic space group Pnma. Detailed structure comparisons in the M-M-P-O and (MMPO) ( n = 1, 2, 6) systems are discussed. Remarkably, KMgPO as one of the cyclophosphate members exhibits a second harmonic generation (SHG) intensity about 0.2 times that of KHPO (KDP), RbCdPO, and CsPbPO also show SHG responses 0.1 times that of KDP. In addition, the related optical properties are discussed. Furthermore, theoretical calculations and dipole moments were calculated to explain the relation of structure and optical properties.

New series of quaternary chalcogenides with firstly discovered isolated edge-sharing (MIII2Q6)6− dimers showing obvious optical anisotropy were reported.