Solvothermal synthesis and properties of three antimony chalcogenides containing transition metal zinc

Syntheses, crystal structure, and photoelectric properties of two Zn-based chalcogenidoantimonates Zn-Sb-Q (Q = S, Se)

Metal chalcogenides are a special class of semiconducting materials characterized by their rich structures and compositions, making them a promising option for a broad range of applications in the field of inorganic chemistry. However, the path forward is not without its challenges, notably in the realms of interface management and enhancing carrier concentration. To address these issues, we solvothermally synthesized two novel chalcogenidoantimonates [Zn(tren)]2Sb2Se5 (1) [tren = tris (2-aminoethyl) amine] and [Zn(tepa)H]2Sb2S6 (2) (tepa = tetraethylenepentamine) utilizing transition metal Zn by band gap optimization strategy in the visible region. Both compounds exhibited distinct zero-dimensional cluster structures, with transition metal complex cations acting as structure-directing agents. A comprehensive analysis of the electronic structure, band gap, and photocurrent response of these crystals was undertaken, revealing significantly enhanced photocatalytic properties compared to preceding studies. This research underscores the potential of antimony chalcogenides in the realm of photoelectric properties and promotes the applications of chalcogenides.

Strong Photocurrent Response of Selenoarsenates With Different Transition Metal Complexes as Structure-Directing Agents

Four selenoarsenates with different transition-metal complexes [Co(tren)₂H]AsSe₄ [tren = tris(2-aminoethyl)amine] (1); [Ni₂(dien)₄](As₂Se₅) (dien = diethylenetriamine) (2); [Zn(tren)]₂(As₂Se₅) (3) and [Mn(tren)]₂(As₂Se₅) (4) were solvothermally synthesized in a mixed solvent of organic amine and alcohol solution. The compounds 1-4 have pyramidal/tetrahedral structures (AsSe₃/AsSe₄), and contain transition metal (Co²⁺, Ni²⁺, Zn²⁺ and Mn²⁺) complex that form distinct zero-dimensional (0-D) clusters. Arsenic atoms form a tetrahedron in compounds 1 and 2; 1 consists of discrete tetrahedral (AsSe₄) and transition metal complex [Co(tren)₂]²⁺; 2 is composed of an anion [As₂Se₅]^4- cluster and transition metal complex [Ni(dien)₂]²⁺. In compounds 3 and 4, arsenic atom forms a pyramidal AsSe₃ and the two pyramidal AsSe₃ share a corner connection to form a dimer [As₂Se₅]^4-; 3 is characterized as a cluster consisting of two unsaturated [Zn(tren)]²⁺ caiton linked by a dimer (As₂Se₅)^4- linkage; in 4, unsaturated [Mn(tren)]²⁺ caiton is linked to two trigonal-bipyramidal [Mn(tren)]Se via dimer (As₂Se₅)^4- to form [Mn(tren)]₄[As₄Se₁₀] cluster. To our knowledge, [Zn(tren)]₂(As₂Se₅) (3) is the first zinc selenoarsenate containing the (As₂Se₅)^4- anion type. Furthermore, the Mn²⁺ ions adopt a trigonal-biyramidal (five-coordinate) and octahedral (six-coordinate) environment. Adding K₂CO₃/Cs₂CO₃ to the synthesis system is necessary and may act as a mineralizer. Several properties of compounds 1-4 have been characterized in our studies, in particular their strong photocurrent response characteristics under visible light irradiation.