Oxidation of hydrosulphide ions on gold Part II: Characterization of gold/aqueous hydrosulphide solution interface

Mimicking the Microbial Oxidation of Elemental Sulfur with a Biphasic Electrochemical Cell

“…The introduction of dissolved elemental sulfur to the organic phase stabilises the CVs when the cell is inside the glovebox, with some signals increasing slightly upon potential cycling ( Figure 3B). Interestingly, the CVs shown in Figure 3B are similar to those reported for aqueous solutions of Na2S in alkaline media on Au electrodes [37][38][39] and, in our opinion, can be rationalized in a similar way. Firstly, previous studies have indicated that both atomic and molecular sulfur can be adsorbed on gold.…”

“…Firstly, previous studies have indicated that both atomic and molecular sulfur can be adsorbed on gold. [38][39][40] Secondly, the shape and behaviour of the CVs with scan rate suggests that the peaks observed inside the potential window arise mainly from surface processes. Thirdly, the asymmetry of the CVs in Figure 3B, where the negative peaks are higher than the positive peaks, suggest that an irreversible chemical reaction is taking place during the potential scans.…”

A Player Often Neglected: Electrochemical Comprehensive Analysis of Counter Electrodes for Quantum Dot Solar Cells

“…In particular, Au electrocatalytic activity can be modulated by varying the size and crystal orientation of Au nanoparticles (NPs), as previously observed . The catalytic performance of Au NPs-based CEs was further improved by using reduced graphene oxide substrate by Zhu et al However, gold is prone to chemisorption of sulfur ions in polysulfide solution, and lower electrocatalytic activity is concomitant to surface passivation by sulfur ions in polysulfide electrolyte. , …”

“…29 The catalytic performance of Au NPs-based CEs was further improved by using reduced graphene oxide substrate by Zhu et al 30 However, gold is prone to chemisorption of sulfur ions in polysulfide solution, and lower electrocatalytic activity is concomitant to surface passivation by sulfur ions in polysulfide electrolyte. 24,31 The use of treated brass has gained fame over the years, being probably the most commonly exploited CE, thanks to the good solar-to-energy conversion performances assured by this material, despite issues related to stability are known also for this approach. 32 This cathode is fabricated by treating in polysulfide electrolyte a piece of brass after acidic activation to expose copper by partial removal of zinc (treatment in HCl at ∼70 °C for variable times according to the procedure adopted in the specific laboratory).…”

Electrocatalytic activity of a graphite electrode coated with hexadecachlorophthalocyanatoiron(II) toward sulfide oxidation, and its possible application in electroanalysis

“…Thus the current maximum at -0.33 V (20 mV s-I) is probably slightly underestimated. C. A suggested mechanism for electrocatalytic oxidation of sulfide ion on a F~"[c~,,Pc(~-)]/ C electrode The electrochemical oxidation of sulfide ion to elemental sulfur has been studied very extensively in the literature (6,(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22); here we will only deal with the involvement of the surface coating of F~" [ C~,~P C (~-) ]…”