⚡ Electrocatalytic Deposition of Copper

“Elektrokimya derslerde anlatıldığı kadar sıkıcı değilmiş, aksine epey keyifliydi!”

This experiment was probably the smoothest lab session I’ve had so far. No stress, no confusion—just pure electrochemistry and shiny copper. That’s probably because I’ve been researching electrochemical energy storage systems—like lithium-ion and sodium-ion batteries—for the past two years. So the concepts we worked with here felt pretty familiar.

And here’s the cool part: there’s a direct connection between electrocatalytic deposition and how electrodes are designed in modern battery systems. In batteries, especially in R&D, we often use electrodeposition techniques to develop thin metal layers or active surfaces on current collectors. So yeah, this experiment felt like home.

🧠 Theory: Electrodeposition 101

Electrodeposition is when metal ions in a solution get reduced and stick to a conductive surface, forming a metallic coating. This is how objects are chrome-plated or how corrosion-resistant coatings are applied.

The basic redox reactions involved in copper electroplating are:

At the anode (oxidation):
Cu(s) → Cu²⁺(aq) + 2e⁻
At the cathode (reduction):
Cu²⁺(aq) + 2e⁻ → Cu(s)

The whole system is governed by Faraday’s Laws of Electrolysis, which relate the electrical charge to the amount of metal deposited. Also, using experimental data, we can estimate Avogadro’s number, which is pretty wild if you think about it.

⚗️ Methodology Overview

Here’s how we did it:

Prepared the electrolyte:
1.87 g CuSO₄·5H₂O was dissolved in 15 mL of 0.1 M H₂SO₄ to make a 0.5 M solution.
Pretreatment:
Electrodes (copper anode & iron cathode) were cleaned mechanically (steel wool) and chemically (vinegar) to remove any oxide layers or impurities.
Setup:
Electrodes were immersed in the electrolyte and connected to a DC power supply. Voltage was applied (1V and 2V) for 5 minutes each.
Measurements:
Before and after the experiment, we measured the mass of the cathode to see how much copper got deposited.

📌 Note: A third trial at 3V was skipped due to current instability—probably due to uncontrolled side reactions.

📈 Results & Observations

We observed shiny, reddish-brown layers of copper forming on the iron cathode. As expected:

At 1V, mass gain = 0.0074 g
At 2V, mass gain = 0.0161 g

✅ Faraday’s Law Check

Using the charge passed through the circuit and the copper’s molar mass, we calculated:

Electrical charge (q):
- 6 C for 1V
- 28.07 C for 2V
Calculated Avogadro’s number:
- 1.608 × 10²³ mol⁻¹ (1V)
- 3.46 × 10²³ mol⁻¹ (2V)

Pretty decent values, considering we only ran the experiment for 5 minutes!

⚠️ Fun Fact:

The actual vs theoretical yield came out to be:

374.5% for 1V
174.24% for 2V

So yeah, our setup wasn’t perfect, but this also shows how easily experimental errors or uncontrolled factors can affect results in electrochemistry. It’s a humbling reminder.

📄 Full Lab Report

Lab group 9, Electrocatalytic Deposition Experiment.İndir

🌐 Extra Resources

If you’re interested in digging deeper, I recommend looking into:

Just search with phrases like “ Electrocatalytic Deposition of Copper” or “Faraday’s Law demo” and you’ll find plenty of good stuff.