The objective: The project was aimed at finding the best combination of nucleation time, deposition time, and deposition potential for palladium nanowires. It was hypothesized, from the third scan of a cyclic voltammagram taken, that the deposition potential would be approximately .400 V. It was hypothseized that the nucleation time would be anywhere ranging from 5-7ms, and the deposition time anywhere from 600s-1800s based on previous research.
Highly Oriented Pyrolitic Graphite (HOPG) Palladium Nitrate Solution: 60% HClO4 (1.54 g/mL, 9.2 M), Water, Pd(NO3)2 #H2O Potentiostat, Saturated Calomel Reference Electrode, Palladium Flag, Working Electrode, SEM, Scotch tape, ECHEM Software, Light microscope
A solution of Pd(NO3)2 H2O was made. The working electrode containing HOPG, counter electrode, and reference electrode were inserted into the solution.
During the conditioning period, the graphite was oxidized using the ECHEM program.
A nucleation pulse was then applied to initiate the nanowire growth. Following their deposition, the wires were taken to the Scanning Electron Microscope (SEM) and imaged.
After repeated trials, the best conditions for optimal nanowire growth was determined to be a deposition potential of .370 V, deposition time of 1200s, and nucleation time of 5ms. The hypothesis that the deposition potential would be near the value of 400 V was confirmed to be correct.
Palladium nanowires of diameters ranging from 62.9 to 159 nm were synthesized by electrodeposition onto highly oriented pyrolitic graphite. Variables of nucleation times, nucleation potentials, and deposition potentials were adjusted to produce the most structured nanowires.
It was concluded that a deposition potential of .370 V, a deposition time of 1200s, and a nucleation time of 6 ms resulted in optimal wire growth.
This project is to find the optimal combination of variables of nucleation time, deposition time, and deposition potential for producing the most structured nanowires by the electrodeposition of palladium onto HOPG.
Science Fair Project done By Kaidi He