New in situ description of electrodepositing multiple nucleation processes under galvanostatic stimuli

Chronoamperometry was used to investigate phase transformations at the early stage of electrodeposition under potentiostatic stimuli. Whilst electrodeposition mostly occurs under galvanostatic stimuli, this work provides a new in situ description using chronopotentiometry to analyse phase transformations during electrodeposition. With theoretical Ohm's law electro-relationship formula derivation, a non-dimensional plot between (ΔE_min/ΔE_T)² and t/t_m was established similar to (I_t/I_max)²vs. t/t_m in the SH model. The non-dimensional plots were verified by the chronopotentiometry curve during gold electrodeposition. This work provides a new method of investigating phase transformation using chronopotentiometry during electrodeposition.

Schematic illustration and equivalent circuit during electrodeposition nucleation at the early stage as controlled by diffusion.

Theoretical and experimental study of the influence of PEG and PEI on copper electrodeposition

Through theoretical calculation and experimental research, the electrodeposition process of preparing copper catalyst in an acid electrolyte with polyethylene glycol (PEG) and polyethylene imine (PEI) as mixed additives is determined.

Theoretical and experimental studies of the influence of gold ions and DMH on cyanide-free gold electrodeposition

Quantum chemical calculations based on density functional theory (DFT) were employed to determine an appropriate gold source for gold electroplating and to ascertain the stable structures of gold-complexes in cyanide-free electrolyte. Based on the charge distribution of 5,5-dimethylhydantoin (DMH) and the bonding energy of gold complexes, Au³⁺ is the appropriate gold source for DMH-based gold electroplating electrolyte to get greater cathodic polarization and [Au(DMH)₄]⁻ with 2N(4)–Au coordination structure is the most stable form of gold ion in the electrolyte. The influence of DMH, used as the complexing agent, on electrochemical behaviors was investigated using cathodic polarization, cyclic voltammetry, and chronoamperometry measurements. With DMH as the complexing agent, the cathodic polarization of gold electrodeposition was significantly enhanced. DMH concentration was determined as 0.30 mol L⁻¹ based on the investigation of the influence of the DMH concentration on cathodic polarization and gold electrodeposit micromorphology. The kinetic features based on cyclic voltammogram measurements revealed that the electrodeposition was an irreversible process under diffusion control with 0.30 mol L⁻¹ DMH as the complexing agent. The ion and electron transfers were obviously inhibited by DMH. The gold electrodeposition process displayed progressive nucleation according to the Scharifker and Hills nucleation model with various applied potentials. The growth rate of the crystal nucleus was reduced by DMH and promoted by a negative shift of E_ap.

Au³⁺ is the appropriate gold source for the DMH-based gold electroplating electrolyte to get greater cathodic polarization.

A composite additive used for a new cyanide-free silver plating bath (II): an insight by electrochemical measurements and quantum chemical calculation

BPY and PAT are effective additives for silver plating due to their ability for strong adsorption on silver surfaces.

Complexing agent study for environmentally friendly silver electrodeposition(ii): electrochemical behavior of silver complex

Silver deposition and electrochemical behaviors of silver complex in the environmentally friendly silver plating bath were studied.

Cyanide-free electrolyte for Au(iii) and Au(i) electrodepositing using DMH as complexing agent

A novel cyanide-free electrolyte is reported for electrodepositing bright gold layers from a solution of both Au(iii) and Au(i).

Synthesis and characterization of chitosan–zinc composite electrodeposits with enhanced antibacterial properties

Chitosan–zinc composite electrodeposits with enhanced broad-spectrum bactericidal property were successfully synthesized based on the chelation action for marine application.

Experimental and theoretical studies of DMH as a complexing agent for a cyanide-free gold electroplating electrolyte

Golden bright gold electrodeposit with a smooth and compact surface can be obtained from the introduced cyanide-free gold electroplating electrolyte.