Templateless synthesis of polypyrrole nanowires by non-static solution-surface electropolymerization

Abstract

Polypyrrole nanowires (PPy-NWs) are synthesized by a novel templateless approach based on non-static solution-surface (NSSS) electropolymerization. The mechanism responsible for PPy-NW formation is the simultaneous oxidation of pyrrole and water, with concomitant formation of hydroxyl radicals and dioxygen nanobubbles. In particular, a localized PPy-NW deposition at the solution-air interface is enabled by solution-surface electropolymerization due to the surface excess of the monomer at the interface favored by the large surface tension of the solvent. In the proposed approach, solution-surface electropolymerization is performed in non-static conditions (NSSS), as the solution-air interface is shifted by flowing the electrolyte solution over the electrode surface. This allows a PPy-NW homogeneous deposition on whatever large area electrode to be rapidly achieved. Parameters influencing the morphology of PPy-NWs are studied, particularly focusing on flow rate, pH of the electrolyte solution, and electropolymerization time. The growth process of PPy-NWs is examined and the way of tuning their resulting morphology is discussed. Morphological investigation by scanning electron microscopy and chemical/electrochemical characterization of PPy-NWs by X-ray photoelectron spectroscopy and cyclic voltammetry, respectively, further support the proposed nanowire formation mechanism. Nanowires with diameter in the range of 40–300 nm are obtained, and the possibility of depositing differently sized nanowires with a predetermined spatial distribution on the same substrate is also demonstrated

Synthesis and modelling of the mechanical properties of Ag, Au and Cu nanowires

“…Current virtual electrode-solution interface process using classical double-layer theory permits digitised controlled electrodeposition system in a microfluidic device for the Ag nanowires synthesis [122,123]. The system employed a programmable light pattern to control the localised electric fields within the microfluid chip that promoted the local electrochemical deposition of free-standing nanowires.…”

Facile synthesis of 3D flower-like Pt nanostructures on polypyrrole nanowire matrix for enhanced methanol oxidation

“…In the panorama of support material for Pt catalyst, also the use of conducting polymers, especially with nanosized structure 26,27 has been successfully proposed as an effective strategy for enhancing metal electrocatalytic activity due to the high catalyst dispersion promoted by polymer nanostructure, and to possible synergistic effect involving both catalyst and support polymer. 28 Nonetheless, to the best of our knowledge, approaches described so far are restricted to Pt nanoparticles, with the only example on PtNF integrated with polyaniline nanober focused on not catalytic sensing applications.…”

“…The use of a whole electrochemical approach results to be benecial respect to chemical synthesis routes 21,25 requiring organic ligand stabilizers which can be difficult to separate and can have a negative impact on the performance of the catalysts, and using multi-step, time consuming and complex procedures limiting applicability and large-scale production. In addition, the use of an electrochemically synthesized nanostructured conducting polymer as support material, contrarily to other developed 3D structure integrating PtNFs, 24,25 offers the additional benets of properly tuning its morphology by controlling some experimental parameters, 27 also in relation to the desired (catalytic) applications, by using a low-cost, commercially available technology.…”

Evolution of a Cu2O Cube to a Hollow Truncated Octahedron and Their Photocatalytic and Electrocatalytic Activity

“…The synthesis of hollow structures can usually be divided into two strategies: template or templateless synthesis. The template method needs the synthesis of a template as a core first, and then the continuous growth of the desired shells can occur, followed by the removal of the template. , The templateless approach usually displays the self-construction of hollow spaces by growth and aggregation of nanocrystallites following the principle of lowest energy, balancing the thermal dynamic and kinetic control, or by selectively etching to achieve the desired structures. − For example, Cu 2 O–CuO–TiO 2 hollow nanocages have successfully prepared using Cu 2 O as the self-template to realize the morphology of hollow nanocages . Hierarchical Prussian white hollow structures with kinked surfaces have been realized through a self-aggregation and etching strategy .…”