Development of a Biodegradable Polymer-Based Photocatalyst System for Solar-Driven Water Purification

Project Abstract

This study presents the development and evaluation of a novel biodegradable polymer-based photocatalyst system designed for solar-driven water purification, addressing the urgent need for sustainable and low-cost water treatment technologies. The system integrates a biopolymer matrix, derived from renewable resources, with doped semiconductor nanoparticles to create a composite capable of harvesting solar energy and promoting the degradation of persistent organic contaminants under ambient conditions. The polymer component offers mechanical stability, flexibility, and environmental compatibility, while the embedded photocatalysts generate reactive oxygen species (ROS) upon illumination, enabling oxidation, mineralization, and detoxification of a wide range of pollutants, including dyes, pharmaceuticals, and endocrine disruptors. Key objectives include (i) synthesizing a biodegradable polymer-based scaffold with optimized porosity and surface area to maximize photocatalyst loading and light absorption; (ii) engineering the polymer-catalyst interface to enhance charge separation and reduce recombination losses; (iii) evaluating the system’s photoactivity under simulated sunlight and natural solar spectra across different pH, salinity, and contaminant concentrations; and (iv) assessing the environmental fate, biodegradability, and potential ecotoxicity of the composite material and its degradation by-products. The synthesis employs green chemistry routes, leveraging solvent-free or aqueous processing, bio-based monomers, and sustainable fabrication methods to minimize environmental footprints. Experimental investigations focus on (a) characterizing the morphological, optical, and electrochemical properties using scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and photoelectrochemical measurements; (b) quantifying photocatalytic performance through standardized dye degradation (e.g., methylene blue, rhodamine B), pharmaceutical simulating compounds, and real wastewater samples to determine apparent rate constants and mineralization efficiency via total organic carbon (TOC) analysis and gas chromatography–mass spectrometry (GC-MS); (c) investigating catalyst stability, reusability, and structural integrity over multiple cycles; and (d) performing life cycle assessment (LCA) to compare environmental impacts with conventional inorganic photocatalysts. Preliminary results indicate that the biodegradable polymer matrix facilitates uniform dispersion of doped photocatalysts, improves light-harvesting efficiency, and enhances charge transfer, resulting in higher degradation rates under visible light compared to bare catalysts. The system demonstrates robust performance in variable water matrices and shows promise for scalable, circular-economy pathways where the photocatalyst support can be recovered or degraded after its service life, minimizing secondary pollution. The research contributes to advancing sustainable solar-driven purification technologies by delivering a recyclable, environmentally friendly photocatalyst platform with high pollutant removal efficiency and compatibility with existing water treatment workflows. Further optimizations will target catalyst loading, polymer crosslinking density, and real-world pilot testing in diverse climatic regions.

Project Overview

What This Project Is About

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A straightforward exploration of a new system that uses a biodegradable polymer to host a photocatalyst. The goal is to clean polluted water using sunlight, without leaving behind non-degradable waste. The project investigates how safe polymers can work with light-activated materials to break down contaminants in water.

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The Problem It Addresses

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Traditional water purification methods rely on materials that may be toxic or non-biodegradable, creating secondary waste. There is a need for an eco-friendly, solar-powered approach that minimizes environmental impact while effectively removing pollutants.

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Objectives of the Project

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1. Identify a biodegradable polymer suitable for hosting a photocatalyst.
2. Develop a simple method to combine the polymer with a light-activated catalyst.
3. Test the system's ability to remove common pollutants under sunlight.
4. Assess the stability and degradation of the polymer in water after treatment.
5. Compare performance with a conventional, non-biodegradable system.

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What You Will Do Step by Step

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1. Review basic concepts of photocatalysis and biodegradable polymers. 2. Select materials and fabricate the polymer-photocatalyst composite. 3. Create small water samples contaminated with representative pollutants. 4. Expose samples to simulated or natural sunlight and measure pollutant levels over time. 5. Evaluate material stability and any degradation byproducts. 6. Analyze data to determine efficiency and repeatability. 7. Compare results with a control system. 8. Write a concise report summarizing findings and implications.

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Expected Outcome

Anticipated results include a practical, solar-driven purification system that effectively reduces contaminants using a biodegradable carrier, with data showing comparable performance to conventional methods and better environmental compatibility.