Search

It is imperative to solve the problem of the electrolytic efficiency of chlorine evolution in extremely dilute chlorine-containing solutions for electrochemical advanced oxidation processes, electrochemical antifouling and chlorine-containing disinfectant preparation. In this paper, an IrO2–Ta2O5 electrode is modified using SnOx, and the activity and selectivity of the chlorine evolution reaction (CER) are successfully improved. The modification of SnOx changes the electronic structure of IrO2–Ta2O5, thus affecting the electrochemical reaction process and mechanism. Compared with the CER activity of the IrO2–Ta2O5 electrode, the CER activity of the SnOx@IrO2–Ta2O5 electrode is increased, whereas the OER activity is decreased. At a current density of 50 mA cm−2, the potential difference between the CER and OER of the SnOx@IrO2–Ta2O5-3 electrode is 254 mV, which is 89 mV higher than that of the IrO2–Ta2O5 electrode. This proves that the selectivity of the CER at the SnOx@IrO2–Ta2O5 electrode has been improved. Due to the low concentration of chloride ions, the current efficiency of the IrO2–Ta2O5 electrode is only 10.7%. The current efficiency of the SnOx@IrO2–Ta2O5-1(2,3) electrode increases to 23.6%, 36.7% and 49.6%, respectively. For the IrO2–Ta2O5 electrode, its rate-determining step (RDS) is the second electron transfer. However, for the SnOx@IrO2–Ta2O5-3 electrode, its RDS is electrochemical desorption. It can be inferred that the modification of SnOx can accelerate the electrochemical desorption of adsorbed Cl. In addition, the application of the SnOx@IrO2–Ta2O5 electrode in the preparation of AEW is investigated. The HClO content in AEW2 (prepared using the SnOx@IrO2–Ta2O5-3 electrode) is 1.85 mmol L−1, which is 4.6 times of that in AEW1 (prepared using the IrO2–Ta2O5 electrode). [ABSTRACT FROM AUTHOR]

AuCo alloys were prepared by magnetron sputtering for the first time without considering the insolubility on the phase diagram. The electronic effect between Au and Co can change the oxygen adsorption energy and the ORR activity. The ORR activity of the Au46Co54 alloy electrode not only exceeded that of Au, but also exceeded that of Pt in basic solution. [ABSTRACT FROM AUTHOR]

Nano-network Ru with definite lattice defects on amorphous Co nanosheets is obtained for the first time. Amorphous Co support can promote the surface Ru to obtain special morphology and modified electronic structure, thus improving HER activity in alkaline solution. A current density of 10 mA cm−2 can be obtained only with an overpotential of 33.5 mV. [ABSTRACT FROM AUTHOR]

RuCo-ANFs with different proportions can be successfully prepared by magnetron sputtering, and their lattice constants can be adjusted accurately. In the RuCo-ANF, there is an obvious electronic interaction between Ru and Co, thus adjusting the ΔGH* on its surface. There is a volcanic relationship between the HER activity and the lattice constant of RuCo-ANF. [ABSTRACT FROM AUTHOR]

AuIr alloy nanoparticles were successfully prepared without using surfactants for the first time despite Au and Ir being immiscible according to phase diagrams. The lattice parameters of the AuIr alloy can be adjusted arbitrarily. The oxygen reduction reaction (ORR) activity of Au5Ir5 alloy is better than that of Au or Ir, and the oxygen evolution reaction (OER) activity of the Au5Ir5 alloy is as good as that of Ir in alkaline solution. [ABSTRACT FROM AUTHOR]

An obvious H-UPD for a nano AuTiO2−x composite has been found for the first time in terms of the electrochemical characteristics of the Au composite. The electronic effect between Au and TiO2 and the oxygen vacancy defect would change the adsorption energy of H and HER activity. The HER activity of the AuTiO2−x electrode is 6.44 times that of the Au electrode. [ABSTRACT FROM AUTHOR]

Electrolyzed oxidizing water (EO water) bactericide is an indirect electrochemical sterilization technology, which is characterized by broad-spectrum, rapid and powerful sterilization. EO water, with a certain amount of available chlorine content (ACC), is generated by electrolysis of an extremely dilute NaCl solution. It is very important to study the preparation process of EO water, including electrode material and electrolytic process. In this paper, the effect of electrode material (platinum, iridium or ruthenium) on the physical and chemical parameters of EO water was investigated first. The effect of electrode composition and roasting temperature on the ACC of EO water was rigorously analyzed. The sterilization effect of EO water produced by different electrode materials was further discussed. In addition, the accelerated service lifetime of the electrode and exchange electrode polarity electrolysis were also investigated. Next, for the electrolysis process, the effects of ion exchange membrane type, current density and electrolyte concentration on the ACC of EO water, anode current efficiency and energy consumption were also studied. Finally, the stability of EO water, that is, the influence of illumination, heating and stirring on the physical and chemical parameters of EO water, was also observed in detail. [ABSTRACT FROM AUTHOR]

The development of highly active and long-term stable electrocatalysts for the hydrogen evolution reaction (HER) is very important. Because of the hysteresis phenomenon, IrO2 is rarely used as a cathode material for the HER. Herein, an IrO2–TiO2 composite oxide was prepared using the thermal decomposition method. The physical and electrochemical characterization of the materials was achieved by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In the process of the HER, the current of IrO2 is only 1.91 mA cm−2@−0.2 V in the first segment scan. However, at the 51, 101 and 151 segment scan, the HER current increases to 6.85, 15.7 and 18.2 mA cm−2@−0.2 V, respectively. During the activation process of IrO2, the HER current has increased ten times. Compared with the HER activity of IrO2, there is almost no hysteresis for the IrO2–TiO2 electrode. In the first segment scan, the HER current has already reached 27.9 mA cm−2@−0.2 V and further increased to 31.1, 33.1 and 35.0 mA cm−2 at the 51, 101 and 151 segment scan. The difference between them is not significant, which means that the IrO2–TiO2 electrode does not need activation. The IrO2–TiO2 electrode has exhibited a higher HER activity than the IrO2 electrode, which may be attributed to the electronic structure modification and the increase of the electrochemical area. [ABSTRACT FROM AUTHOR]

Combined computational and experimental studies reveal a noble, non-d-band effect on Ag activation and electrocatalysis: upon coating Ag onto the even more inert Au surface, the catalytic activity toward the oxygen reduction reaction in alkaline media can be improved by about half an order of magnitude in comparison to the usual Ag surface. [ABSTRACT FROM AUTHOR]

A nano Ir x Mn (1- x ) O y hybrid electrode with a L1 2 -IrMn 3 phase was used as a bifunctional catalyst with ultra-low iridium loading for overall water electrolysis in an acid solution for the first time. The HER activity of the Ir x Mn (1- x ) O y hybrid electrode not only exceeded that of IrO 2 , but also exceeded that of Pt/C. The OER activity of the Ir x Mn (1- x ) O y hybrid electrode also exceeded that of IrO 2 .

Electrochemical water splitting technology is considered to be the most reliable method for converting renewable energy such as wind and solar energy into hydrogen. Here, a nanostructured RuO 2 /Co 3 O 4 -RuCo-EO electrode is designed via magnetron sputtering combined with electrochemical oxidation for the oxygen evolution reaction (OER) in an alkaline medium. The optimized RuO 2 /Co 3 O 4 -RuCo-EO electrode with a Ru loading of 0.064 mg cm -2 exhibits excellent electrocatalytic performance with a low overpotential of 220 mV at the current density of 10 mA cm -2 and a low Tafel slope of 59.9 mV dec -1 for the OER. Compared with RuO 2 prepared by thermal decomposition, its overpotential is reduced by 82 mV. Meanwhile, compared with RuO 2 prepared by magnetron sputtering, the overpotential is also reduced by 74 mV. Furthermore, compared with the RuO 2 /Ru with core-shell structure ( η = 244 mV), the overpotential is still decreased by 24 mV. Therefore, the RuO 2 /Co 3 O 4 -RuCo-EO electrode has excellent OER activity. There are two reasons for the improvement of the OER activity. On the one hand, the core-shell structure is conducive to electron transport, and on the other hand, the addition of Co adjusts the electronic structure of Ru., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

An obvious H-UPD for a nano AuTiO2-x composite has been found for the first time in terms of the electrochemical characteristics of the Au composite. The electronic effect between Au and TiO2 and the oxygen vacancy defect would change the adsorption energy of H and HER activity. The HER activity of the AuTiO2-x electrode is 6.44 times that of the Au electrode.