Yumeng Yang

Adsorption and protective behavior of BTAH on the initial atmospheric corrosion process of copper under thin film of chloride solutions

The initial corrosion process of copper and the corrosion resistance mechanism of Benzotriazole under chloride-containing thin electrolyte layer (TEL) was investigated. After theoretical calculation and experimental characterization, the forming process of [Cu(I)BTA]n film was chemically adsorbed on copper surface by Cu-N bond tightly; corrosion rate increased as TEL thickness decreased. Whilst, energy distribution plot of electrochemical noise provided the validity of corrosion type, and the purported corrosion energy (Ec) deduced from electrochemical noise was approximately proportion to corrosion rate (1/Rct) with and without the anticorrosion film, which denoted the feasibility to determine corrosion rate by nondestructive on-line monitoring electrochemical noise progress.

Preparation of AAO-CeO2 nanotubes and their application in electrochemical oxidation desulfurization of diesel

The coaxial arrays of AAO-CeO2 NTs have been successfully galvanostatically deposited on an anode, characterized and adopted as a catalyst for removing organic sulfurs from diesel. The influence of the main electrochemical oxidation factors on the efficiency of desulfurization have also been investigated. The results show that the fabrication process of AAO-CeO2 NTs is accompanied by the formation of a new phase, namely Al3Ce, and the main oxidation products of the diesel are soluble inorganic sulphides, especially Ce2(SO4)3. When compared with dibenzothiophene and 4, 6-dimethyldibenzothiophene, benzothiophene is much more easily removed, with a removal efficiency that reaches 87.2%. Finally, a possible electrochemical oxidation desulfurization pathway for diesel is proposed.

Effects of anions on the underpotential deposition behavior of Cu on polycrystalline Pt

The process of Cu underpotential deposition (UPD) on polycrystalline Pt (pc Pt) has been investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy techniques using (bi)sulfate and perchlorate (with/without the addition of a small amount of NaCl) as supporting electrolytes, respectively. The results showed that the adsorption capacity of the anions influences both the reversibility and charge transfer resistance (Rct) of Cu UPD reactions on pc Pt. With a negative shift of the applied potential, Rct of the (bi)sulfate system decreases monotonously, whereas Rct of the perchlorate system (with/without Cl− ions) decreases at first and then increases. Cu UPD on pc Pt follows Langmuir-type adsorption and two-dimensional nucleation/growth mechanisms. The specific adsorption anions ((bi)sulfate and chloride ions) can not only enhance the Cu UPD process by decreasing Rct, but also favor instantaneous 2D nucleation and subsequent grain growth. Finally, the possible deposition mechanisms of the Cu UPD process in the presence of specific adsorption anions were proposed.

Correlation between the corrosion rate and electrochemical noise energy of copper in chloride electrolyte

An electrochemical noise technique has been applied to describe the corrosion process of copper. The results show that the sampling frequency clearly changes both the energy distribution plot and the power spectral density spectra, which should be taken into consideration strictly and logically before an electrochemical noise test. The corrosion energy, (Ec), deduced using the fast wavelet transform method showed a similar variation trend with corrosion rate. Hence, the proposed parameter Ec represents the corrosion rate or severity.

Electrodeposition of Ni and CeO2/Ni Nanotubes for Hydrogen Evolution Reaction Electrode

Ni NTs and CeO2-Ni nanotubes (NTs) have been prepared by galvanostatic electrodeposition in anodic aluminum oxide (AAO) Templates. Scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopic (EDS) and X-ray Diffraction (XRD) are used to characterize the prepared NTs. The results showed that the preparation process of CeO2-Ni NTs was accompanied by the formation of many new phases CeNix (x = 1, 2, 3.5 or 5) and preferential orientation crystal face of Ni in CeO2-Ni NTs is 〈111〉, which is different from that Ni 〈200〉 in Ni NTs. Then linear scan voltammetry (LSV) is applied to test the electrocatalytic activity for hydrogen revolution reaction (HER) of the two electrodes in 1 M NaCl aqueous solution and find that both of the two materials exhibited good performance. Finally, the kinetics analyses from the HER process showed that Tafel slope b was mainly dependent on phase composition and electric conductivity of the electrode, while j0 was mainly dependent on its real specific surface area.