Introduction

Hydrogen is a clean fuel that produces only water when burned, making it a key solution for sustainable energy. Traditional hydrogen production methods rely on fossil fuels, contributing to greenhouse gas emissions. This project explores a greener approach—photocatalytic water splitting, where sunlight and catalysts are used to break water molecules (H₂O) into hydrogen (H₂) and oxygen (O₂). This method mimics natural photosynthesis and offers a promising pathway toward renewable hydrogen energy.

Statement of the Problem

The global energy crisis and environmental degradation demand sustainable energy sources. Hydrogen fuel has high energy efficiency but is mainly produced via steam reforming, which emits CO₂. There is a need for an eco-friendly, low-cost hydrogen production method that does not contribute to climate change. Photocatalytic water splitting presents a viable alternative, but challenges such as low efficiency, catalyst degradation, and scalability must be addressed.

Objectives

• To demonstrate the feasibility of generating hydrogen gas from water using sunlight and a photocatalyst.
• To test different catalysts (e.g., titanium dioxide, graphene, or metal oxides) for efficiency in hydrogen production.
• To measure the amount of hydrogen produced under different conditions (light intensity, water pH, catalyst concentration).
• To assess the potential of this technology for large-scale clean energy production.

Apparatus

• Solar lamp (or natural sunlight)
• Beakers (250 mL, 500 mL)
• Glass reaction vessel (with a gas outlet)
• Magnetic stirrer
• pH meter
• Gas collection tubes
• Gas syringe (for measuring hydrogen output)
• Spectrophotometer (for analyzing catalyst performance)

Materials

• Distilled water
• Photocatalyst (Titanium dioxide – TiO₂, Zinc Oxide – ZnO, or Graphene-based catalysts)
• Sacrificial agent (Methanol or Ethanol to enhance reaction efficiency)
• Noble metal co-catalysts (Platinum nanoparticles for enhanced activity)
• Electrodes (for additional electrochemical water splitting)

Procedure

Step 1: Preparing the Catalyst Suspension

1. Dissolve 1g of the selected photocatalyst (e.g., TiO₂) in 100 mL of distilled water.
2. Add a sacrificial agent (such as methanol) to improve hydrogen production.

Step 2: Exposure to Sunlight

1. Place the reaction vessel under a strong light source (solar lamp or direct sunlight).
2. Stir continuously using a magnetic stirrer to ensure even reaction.
3. Monitor the reaction for gas bubbles forming at the electrode/catalyst surface.

Step 3: Hydrogen Collection and Measurement

1. Use a gas collection tube to trap hydrogen bubbles.
2. Measure the volume of gas collected over a period of time.
3. Analyze the rate of hydrogen production under different conditions (varying light intensity, catalyst type, and pH levels).

Observation

• Bubbles form in the reaction vessel, indicating the production of hydrogen and oxygen gases.
• More hydrogen is produced when a platinum co-catalyst is used.
• Under stronger sunlight, the reaction is faster and more efficient.
• The color of the catalyst suspension may change, indicating photocatalytic activity.

Discussion

The project successfully demonstrates that water can be split into hydrogen and oxygen using sunlight and catalysts. Titanium dioxide (TiO₂) is an effective photocatalyst but has limitations—it primarily absorbs UV light. To improve efficiency, doping with graphene or metal nanoparticles (e.g., platinum) can enhance visible-light absorption.

Challenges include low hydrogen yield and slow reaction rates, which could be addressed by:

• Using more efficient catalysts (e.g., modified ZnO, perovskites).
• Enhancing surface area of catalysts for better light absorption.
• Employing artificial photosynthesis techniques to mimic plant energy conversion.

Conclusion

This project highlights photocatalytic water splitting as a potential method for clean hydrogen production. Although current yields are low, continued research into better catalysts and reaction conditions can improve efficiency, making it a viable renewable energy source for the future. This method could one day replace fossil fuels in hydrogen production, leading to a more sustainable and green energy system.