Tris(2-selenonicotinamide)bismuth(III) Complex as a Promising Single-Source Precursor for Photoresponsive 2D-Bi2Se3 Nanostructures

Two-dimensional (2-D) Bi₂Se₃ nanostructures have emerged as fine candidates due to their appealing performance toward energy conversion and storage applications. In view of this, a simple and economically viable method for their preparation is highly desirable. Herein, we present the synthesis, characterization, and structural elucidation of a new air-stable Bi-nicotinamide selenolate complex: [Bi{SeC₅H₃(3-CONH₂)}₃] (1). This complex serves as an efficient single-source molecular precursor (SSP) for the facile preparation of phase-pure Bi₂Se₃ nanostructures. The as-prepared Bi₂Se₃ nanostructures were characterized using microstructural analyses such as powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDS), and electron microscopy techniques to assess their phase purity, elemental composition, crystal structure, and morphology. This study also attempts to understand the effect of reaction conditions on the crystallinity, size, and morphology of nanostructures. The optical band gap of the nanostructures was tuned within the range of 1.9–2.0 eV, which is blue-shifted with respect to the corresponding bulk band gap and is suitable for energy conversion applications. Liquid junction photoelectrochemical cells fabricated from the as-prepared Bi₂Se₃ nanostructure exhibit good photoresponsivity and decent photostability, which project them as amenable candidates for alternative photon absorber materials.