Splitting Water | Science Project

Summary

In this video, the process of creating an electrochemical cell to split water into hydrogen and oxygen is demonstrated using simple electronic components. The setup includes building a galvanostat to control the current, positioning nickel electrodes in a phosphate buffer, and adding a cobalt catalyst to enhance the reaction. The voltage required to split the water decreases as the catalyst forms, showing improved efficiency. The experiment highlights the importance of electrochemical reactions in renewable energy production, specifically in hydrogen fuel cells, with a focus on voltage control and catalyst efficiency.

Takeaways

• 😀 Using simple electronic parts like batteries, resistors, and a breadboard, you can build a galvanostat to control the current in an electrochemical cell.
• 😀 A galvanostat maintains a constant current in the electrochemical cell, which is essential for splitting water into hydrogen and oxygen.
• 😀 Batteries are connected in series (positive to negative) to provide a higher total voltage, with care to avoid any short circuits.
• 😀 The resistor is used to regulate the current in the electrochemical cell, ensuring controlled electrolysis of water.
• 😀 A voltmeter is used to monitor the voltage across the electrochemical cell, which initially reads the sum of battery voltages before the cell is activated.
• 😀 Nickel electrodes are used in the electrochemical cell, but they need to be cleaned (using a cola beverage) and then coated with a catalyst to improve their performance.
• 😀 A styrofoam holder is used to maintain a consistent distance between the electrodes in the cell during the experiment.
• 😀 Adding a conductive solution (like phosphate buffer) to the electrochemical cell allows the current to flow, enabling water splitting to occur.
• 😀 The voltage across the electrochemical cell drops after the catalyst (cobalt nitrate) is added, as it makes the water splitting reaction more efficient.
• 😀 The reaction's efficiency increases when cobalt nitrate is used to grow a catalyst on the electrodes, lowering the voltage required to split water.
• 😀 The final voltage reading across the electrochemical cell, after adding the catalyst, shows the authentic voltage required to split water into hydrogen and oxygen, demonstrating the efficiency of the catalyst.

Q & A

What is the purpose of a galvanostat in the experiment?

The galvanostat is used to control or hold the current constant in the electrochemical cell during the water splitting reaction.

Why is it important to ensure that the battery leads do not touch each other?

If the battery leads touch each other, it would cause a short circuit, which could lead to overheating or damage to the system.

How does the addition of a resistor help in the experiment?

The resistor controls the current flow through the electrochemical cell, ensuring that the current remains at a desired level for the reaction to proceed efficiently.

What is the role of the voltmeter in the experiment?

The voltmeter is used to monitor the voltage across the electrochemical cell, providing real-time data on the electrochemical reaction's progress.

Why are nickel electrodes chosen for the electrochemical cell?

Nickel electrodes are used because they are common and durable, although they are not the best catalysts for hydrogen and oxygen production. The experiment aims to improve their catalytic performance.

How does the cola beverage help prepare the nickel electrodes?

The cola beverage, being slightly acidic, helps clean the surface of the nickel electrodes by removing impurities, making them more suitable for the electrochemical reaction.

Why is a conductive solution necessary in the electrochemical cell?

The conductive solution, like phosphate buffer, allows charge to flow through the electrochemical cell, enabling the current to pass and the water splitting reaction to occur.

What happens to the voltage reading when the catalyst (cobalt nitrate) is added?

The voltage reading decreases because the catalyst makes the reaction more efficient, lowering the energy required to sustain the water splitting process.

What is the significance of the dark coating on the electrode after adding the catalyst?

The dark coating is the catalyst formed on the electrode, which facilitates the oxygen evolution reaction, improving the efficiency of the electrochemical cell.

Why is it important to swap the electrochemical cell solution with fresh phosphate buffer?

Swapping to fresh phosphate buffer ensures that no additional catalyst is formed, allowing the voltage measurement to reflect the authentic voltage required for water splitting without any catalytic enhancement.