Electrochemical Synthesis of Bismuth Particles: Tuning Particle Shape through Substrate Type within a Narrow Potential Window

Abstract

Bismuth (Bi) electrodeposition was studied on Si/Ti/Au, FTO-, and ITO-coated glasses from acidic nitrate solutions with and without gluconate within a narrow potential window (∆E = 80 mV). This potential range was sufficient to observe a change in particle shape, from polyhedrons (including hexagons) to dendrites, the trend being slightly different depending on substrate activity. In all cases, though, the formation of dendrites was favoured as the applied potential was made more negative. Bi particles were more uniformly distributed over the substrate when sodium gluconate was added to the electrolyte. X-ray diffraction analyses of dendrites grown at −0.28 V indicated that they exhibit the rhombohedral phase of Bi and are predominantly oriented along the (003) plane. This orientation is exacerbated at the lowest applied potential (−0.20 V vs. Ag|AgCl) on glass/ITO substrate, for which completed and truncated hexagons are observed from the top view scanning electron microscopy images.

Microstructure and electrical transport in electrodeposited Bi films

“…In general, all films display a similar morphology, exhibiting a granular topography with well-defined crystals and a clear tendency to anisotropic rhombohedral formations, in agreement with the rhombohedral Bi phase revealed by X-ray diffraction. However, the use of different synthesis conditions does have a significant influence on roughness and grain size of the films, as expected [29,31,34,48].…”

“…Jiang et al [31] focus on the importance of the deposition substrate, and several other studies are devoted to the importance of the additives, hence electrolyte composition [32]. Finally, other studies analyse the effect of deposition substrate and potential [34].…”

Early-Stage Growth Mechanism and Synthesis Conditions-Dependent Morphology of Nanocrystalline Bi Films Electrodeposited from Perchlorate Electrolyte

“…Bi nanowires, imbedded in Al 2 O 3 matrix, showed their potential use for enhancing thermoelectric performance [34][35][36][37][38][39][40]. Many authors have focused on the Bi deposition onto noble metals (evaporated Au and polycrystalline Cu) and non-metallic substrates, such as semiconductors [41,42] and glassy carbon [43]. However, the number of authors who produce bismuth films onto metallic substrates is very limited [23,44,45].…”

Underpotential‐Assisted Electrodeposition of Highly Crystalline and Smooth Thin Film of Bismuth

“…The applications of Bi include the development of several technological devices thanks to its outstanding features: magnetoresistance, superconductivity, thermoelectrical, optical and electronic anisotropy, quantum effect, valleytronics and spintronics material and topological insulator, but even application in catalysis and heavy metals analysis . The preparation of Bi thin films involves low pressure vapour phase depositions and electrodeposition from solution on various substrates . Electrodeposition is usually performed at room conditions, which makes it cheaper with respect to other techniques and more attractive for large‐scale production; moreover, it can provide highly ordered and crystalline deposits .…”

“…[20][21][22] The preparation of Bi thin films involves low pressure vapour phase depositions [23][24][25][26][27] and electrodeposition from solution on various substrates. [28][29][30][31] Electrodeposition is usually performed at room conditions, which makes it cheaper with respect to other techniques and more attractive for large-scale production; moreover, it can provide highly ordered and crystalline deposits. [32][33][34][35] Unfortunately, in the case of bismuth, only few works manage to obtain a continuous and uniform deposit through electrochemical methods, [36][37][38] while most electronic applications require smooth deposits to maximise the charge transfer and other performances.…”