Investigation of Photocatalytic Degradation of Dyes Using Metal Oxide Nanoparticles

CHAPTER ONE

1.1 Background to the Study

The rapid growth of the textile and dye industries has resulted in significant environmental pollution, especially through the discharge of colored wastewater. These dye effluents reduce light penetration in aquatic systems and release toxic substances that threaten both aquatic life and human health (Kaur & Malana, 2019). Traditional wastewater treatment methods such as filtration and chlorination often fail to remove dyes completely because of their stable aromatic structures.
In recent years, researchers have focused on photocatalysis as an advanced oxidation process for removing organic pollutants. Metal oxide nanoparticles such as titanium dioxide (TiO₂), zinc oxide (ZnO), and iron oxide (Fe₂O₃) have emerged as efficient photocatalysts because of their large surface areas and high photoactivity (Chen et al., 2020). When exposed to light, these nanoparticles generate reactive oxygen species that break down dye molecules into harmless by-products like carbon dioxide and water.
Therefore, investigating the photocatalytic degradation of dyes using metal oxide nanoparticles offers an eco-friendly approach to wastewater purification. Understanding how different metal oxides perform under varying conditions will enhance industrial applications and contribute to environmental sustainability.

1.2 Statement of the Problem

Many industrial dyes resist degradation by conventional treatment methods. The inability to eliminate these pollutants completely results in the accumulation of toxic chemicals in ecosystems. There is a pressing need to identify more efficient and sustainable photocatalysts that can achieve faster and cleaner degradation.

1.3 Objectives of the Study

1. To synthesize and characterize selected metal oxide nanoparticles.

2. To evaluate their photocatalytic efficiency in degrading common industrial dyes.

3. To determine the influence of light intensity, pH, and catalyst concentration on degradation efficiency.

1.4 Significance of the Study

This study will contribute to cleaner environmental practices by promoting the use of sustainable nanotechnology for wastewater treatment. The findings will benefit industries, researchers, and environmental policymakers interested in developing cost-effective and eco-friendly solutions.

1.5 Scope of the Study

The study focuses on a limited range of dyes and selected metal oxide nanoparticles. Photocatalytic tests will be conducted under controlled laboratory conditions to evaluate degradation performance.