Accessing copper selenide nanostructures through a 1D coordination polymer of copper(II) with 4,4′-dipyridyldiselenide as a molecular precursor.

Copper selenide nanostructures have attracted growing attention due to their potential application in cost effective and sustainable solar cells and photocatalysis. This study describes the facile conversion of a new one dimensional copper(II) coordination polymer constructed from 4,4′-dipyridyldiselenide (1D-CupySe) into copper selenide nanostructures. The structure of 1D-CupySe elucidated from single crystal XRD revealed the formation of a one-dimensional zig-zag chain of the [{Cu₂(μ(O,O′)-OAc)₄}(μ(N,N′)-4,4′-py₂Se₂)] repeating unit. Interestingly, the diselenide linkage remains intact in the polymer which can be readily cleaved under mild thermolytic conditions, thereby facilitating intra-molecular selenium transfer to the Cu(II) center. The solvent assisted breakdown of 1D-CupySe revealed the formation of Cu_2−xSe nanostructures. Importantly, different compositions of Cu_2−xSe (Cu_1.75Se and Cu₂Se) could be isolated by the choice of solvent. The as-prepared nanostructures have been thoroughly characterized by pXRD, EDS, electron microscopy and DRS for assessing their phase purity, crystal structure, elemental composition, morphology and optical properties. The nanostructures exhibit a narrow band gap in the range of 2.3–2.45 eV. Prototype photoelectrochemical cells fabricated using the nanostructures exhibit high current generation which makes them suitable alternatives for non-toxic and low-cost photon absorber materials. [ABSTRACT FROM AUTHOR]