Binary–Ternary Bi₂S₃–AgBiS₂ Rod-to-Rod Transformation via Anisotropic Partial Cation Exchange Reaction

Abstract

Nanoscale chemical transformations based on partial cation exchange reactions are known as a componentincreased, shape-maintaining means for the design and tunable preparation of ternary or multinary metal chalcogenide compounds. Herein, we present a new material couple, Bi 2 S 3 −AgBiS 2 , to detail the binary−ternary chemical transformation via partial cation exchange and its reaction thermodynamics and kinetics. The preformed Bi 2 S 3 nanorods (NRs) act as both the reactant and the parent template, within which the partial exchange of Bi 3+ with Ag + cations proceeds under a silver-rich, diffusion-controlled regime, leading to the formation of energetically favorable AgBiS 2 . The NR shape preservation involving sulfur sublattice rearrangement is due to the proper diameter thickness (∼12 nm) of parent Bi 2 S 3 NRs and the rapid establishment of equilibrium-phase AgBiS 2 , as supported by X-ray diffraction measurements and the pseudobinary Ag 2 S−Bi 2 S 3 phase diagram. Interestingly, the finding of a AgBiS 2 −Bi 2 S 3 −AgBiS 2 intermediate with axially segmented heterostructures reveals the real NR-to-NR conversion trajectory and the shape-induced exchange reaction anisotropy at the ends and middle of Bi 2 S 3 NRs. Additionally, the resultant AgBiS 2 NRs with a measured band gap of ∼0.86 eV exhibit potential for photoelectronic applications because of their impressive visible−near-infrared absorption and photoconductivity.

Deep Eutectic Solvent-Assisted Microwave Synthesis of Thermoelectric AgBiS2 and Cu3BiS3

“…As evident from the SEM image of the DES-synthesized AgBiS 2 sample (2 h of dwelling, phase pure by PXRD), AgBiS 2 particles possess a rod-like morphology, similar to that of Bi 2 S 3 (Figures and S4). The morphologies of AgBiS 2 and Bi 2 S 3 particles in this work are similar to those of AgBiS 2 nanorods that were made from pre-synthesized Bi 2 S 3 nanorods in oleylamine . However, Bi 2 S 3 synthesized in DES made of thioacetamide and choline chloride in an autoclave resulted in nanowire morphology …”

“…The morphologies of AgBiS 2 and Bi 2 S 3 particles in this work are similar to those of AgBiS 2 nanorods that were made from pre-synthesized Bi 2 S 3 nanorods in oleylamine. 62 However, Bi 2 S 3 synthesized in DES made of thioacetamide and choline chloride in an autoclave resulted in nanowire morphology. 19 The optical properties of the synthesized AgBiS 2 and Cu 3 BiS were investigated using diffuse reflectance spectroscopy.…”

Understanding the Crystal Growth of Bismuth Chalcohalide Nanorods through a Self-Sacrificing Template Process: A Comprehensive Study

“…The transformation of one bismuth compound into another is mainly reported for oxides/oxyhalides and sulfides, 51−53 or in cation exchange cases. 54,55 To the best of our knowledge, this is the first experimental study of the mechanism in which a sulfide transforms into a sulfoiodide. The reaction medium under study is monoethylene glycol, which is a coordinating solvent and plays an important role in promoting the entrance of iodine atoms into the Bi 2 S 3 structure for the formation of BiSI.…”

Enhanced Photophysical Properties of Bi2S3/AgBiS2 Nanoheterostructures Synthesized via Ag(I) Cation Exchange-Mediated Transformation of Binary Bi2S3

“…The ionic radius of Ag + ion is 1.15 Å, which is quite favorable for the intercalation, and can initiate the CE process. Recently, Wang et al in their article have reported the conversion of Bi 2 S 3 to AgBiS 2 and highlighted the growth mechanism extensively . In our work, the Ag + -mediated CE has been done in a relatively low temperature (70 ° C) and via an intermediate heterostructure formation.…”

“…Recently, Wang et al in their article have reported the conversion of Bi 2 S 3 to AgBiS 2 and highlighted the growth mechanism extensively. 49 In our work, the Ag + -mediated CE has been done in a relatively low temperature (70 °C) and via an intermediate heterostructure formation. Interestingly, this intermediate heterostructure is found to be stable and exhibit a type-I band alignment.…”