The use of non-cavitating coupling fluids for intensifying sonoelectrochemical processes

In Situ Sonoactivation of Polycrystalline Ni for the Hydrogen Evolution Reaction in Alkaline Media

“…Ultrasound generates heat, and it is necessary to circulate cooling water to keep the bulk electrolyte temperature ( T ) constant. In this regard, a refrigerated circulator (JULABO, Germany) was connected to the sonoelectrochemical cell to maintain the temperature at 298 ± 1 K. This sonoelectrochemical cell employed in this study, also called the Besançon cell , has been described in detail elsewhere. ,, The working electrode (WE) was a replaceable, disc-shaped solid electrode (E5TQ series, Pine) which in this case was polycrystalline Ni (99.99% in purity, Goodfellow; Ø = 5.00 mm) having a geometric surface area ( A geom ) of 0.196 cm 2 . The reference electrode (RE) was a custom-made reversible hydrogen electrode (RHE) .…”

“…It is well known that the propagation of an ultrasonic wave into a liquid leads to acoustic cavitation . The use of ultrasound in electrochemistry, also known as sonoelectrochemistry , yields: (a) an area of extreme mixing within the area of the ultrasonic transducer, (b) electrode and electrolyte degassing, (c) electrode erosion and cleaning, thus activation, and (d) an increase in the electrolyte bulk temperature, (e) acoustic cavitation (creation and implosion of cavitation bubbles on the electrode surface), (f) the production of highly reactive radicals (e.g., H · and OH · ) and hydrogen peroxide (H 2 O 2 ), also known as water sonolysis (see the Supporting Information for the complete water sonolysis chemical reactions), and (g) sono­(electro)­chemiluminescence. − It is also known that ultrasonication greatly improves the electrocatalytic properties of metallic surfaces due to cavitation erosion and cleaning induced by high-velocity jets of liquid generated by the implosion of cavitation bubbles on/near the surfaces. − …”

Hydrodynamic behavior of bubbles at gas-evolving electrode in ultrasonic field during water electrolysis

“…1 (a)). This double-jacketed reactor, called a Besançon cell, prevents electrolyte contamination due to erosion of the ultrasonic probe tip and makes it easier to control the electrolyte temperature [27] , [28] . The inner dimension of the reactor was 50 × 50 × 65 mm (width × depth × height).…”

“…During sonication, the temperature of the liquid inside the inner cell increases as the mechanical energy is converted to heat. The transmitted acoustic power was measured by sonicating 10 ml ultrapure water in the inner cell for 60 s. During sonication, both the inlet and the outlet of the sonoreactor were closed to measure the acoustic power, and the temperature of the ultrapure water was recorded every second by a data logging thermometer [28] . Using a standard calorimetric method presented by Mason [29] and Contamine [30] , the acoustic power can be calculated using Eq.…”

Does Power Ultrasound (26 kHz) Affect the Hydrogen Evolution Reaction (HER) on Pt Polycrystalline Electrode in a Mild Acidic Electrolyte?

“…1(a)). This sonoreactor also called the Besançon cell has been fully characterized and well-described elsewhere [21,22,39]. The working electrode (WE) was either a polycrystalline platinum (Pt-poly) disc (∅ = 0.182 cm) of geometric surface area (A g ) of 0.027 ± 0.002 cm 2 or a Pt-poly wire (L = 8 cm, ∅ = 0.1 cm).…”