A Versatile Route for Synthesis of Metal Nanoalloys by Discharges at the Interface of Two Immiscible Liquids

Abstract

Discharge in liquid is a promising technique to produce nanomaterials by electrode erosion. Although its feasibility was demonstrated in many conditions, the production of nanoalloys by in-liquid discharges remains a challenge. Here, we show that spark discharge in liquid cyclohexane that is in contact with conductive solution, made of a combination of Ni-nitrate and/or Fe-nitrate and/or Co-nitrate, is suitable to produce nanoalloys (<10 nm) of Ni-Fe, Ni-Co, Co-Fe, and Ni-Co-Fe. The nanoparticles are synthesized by the reduction of metal ions during discharge, and they are individually embedded in C-matrix; this latter originates from the decomposition of cyclohexane. The results open novel ways to produce a wide spectrum of nanoalloys; they are needed for many applications, such as in catalysis, plasmonic, and energy conversion.

Dual catalytic activity of a cucurbit[7]uril-functionalized metal alloy nanocomposite for sustained hydrogen generation: hydrolysis of ammonia borane and electrocatalysts for the hydrogen evolution reaction

“…The differences in the two lattice layers of ∼0.16 nm or ∼0.18 nm in the HRTEM figures, confirm the presence of both Co and Ni metals in the nanoalloy form. 22,43 Selected area electron diffraction (SAED) patterns recorded for both (Co 85 :Ni Fig. S5 † illustrates the N 2 adsorption-desorption isotherms at 77 K and the corresponding pore-size distributions of Co 85 : Ni 15 and (Co 85 :Ni 15 ) 50 :(CB7) 50 catalysts, their respective Brunauer-Emmett-Teller (BET) surface areas were obtained as 54.8 m 2 g −1 and 84.4 m 2 g −1 , respectively, using the N 2 gas analyzer (Table 1).…”

“…Moreover, the larger mesopores in (Co 85 :Ni 15 ) 50 : (CB7) 50 catalyst obtained from the QSDFT model fitting of the N 2 adsorption isotherm synergistically boost the electrolyte transport and enhance the transport/diffusion of the catalytic reactant species towards the exposed HER active sites and reduces the mass transfer resistance (Table 2). 43 Moreover, the CB7-functionalized nanocomposite gains more attraction for its practical implementation from the fact that the LSV measurements with the magnetically separated (Co 85 :Ni 15 ) 50 :(CB7) 50 nanocomposite catalysts recovered after the hydrolysis, coating over a glass electrode also displayed HER profile in perfect overlap with the freshly prepared composite (Fig. 3A, trace (f )).…”

“…The high exchange current density of 2.17 × 10 −3 mA cm −2 also suggested faster kinetics of the (Co 85 :Ni 15 ) 50 :(CB7) 50 catalyst. 43 Furthermore, electrochemical impedance spectroscopy was also performed to evaluate charge transfer resistance in both catalysts. Fig.…”

Oil–water interface dynamics and electrical breakdown in pulsed electric field

“…The discharge begins to burn in a mixture of water and oil vapors between the HV electrode and the water surface acting as a liquid electrode. This feature-a discharge in vapors of two liquids-is of potential use for plasmaassisted chemical reactions, for example, with liquid hydrocarbons (synthesis, conversion, etc) [52,53].…”

Morphological Design and Synthesis of Nanoparticles

“…Advancements in synthetic methods are essential for the practical application of nanoparticles, enabling the mass production of nanomaterials with controlled properties and ensuring their widespread use in various industries. Hamdan and Stafford [ 15 ] introduce us to a versatile route for the synthesis of metal nanoalloys using a novel spark discharge method for producing metal nanoalloys in a liquid environment, exploiting the interface between two immiscible liquids. The technique enables the synthesis of nanoparticles with controlled composition and embedded in a carbon matrix, opening up new avenues for the creation of nanoalloys with tailored properties for catalysis, plasmonics, and energy conversion applications.…”