A new global study has revealed that research into photocatalytic degradation of microplastics has sharply increased over the past two decades, offering hope for addressing the growing threat of plastic pollution. The analysis reviewed 204 scientific articles published between 2005 and 2024 and highlighted the growing role of light-driven nanomaterials in breaking down microplastic and nanoplastic waste.
Photocatalysis involves using materials that, when exposed to light, produce reactive oxygen species capable of breaking apart plastic polymers. This method is considered environmentally friendly because it requires no harmful chemicals and operates under mild conditions using sunlight or artificial light.
China has emerged as the leader in this field, accounting for nearly 42% of the total research output, followed by India, Mexico, the United Kingdom, and Japan. These countries are also involved in numerous international collaborations, with Italy, Iran, and Saudi Arabia standing out for their cooperative research efforts with major nations like the US and South Korea.
Among the institutions contributing significantly are Mexico’s Universidad Autónoma de Nuevo León and India’s University of Calcutta, both of which have advanced research on photocatalytic treatment of microplastics.
Titanium dioxide remains the most studied material in this research area due to its high effectiveness and stability. Other materials like zinc oxide, graphitic carbon nitride, and various modified semiconductors are also gaining attention for their improved performance. Common plastics targeted in these studies include polyethylene, polypropylene, polystyrene, and polyvinyl chloride the same types often found polluting oceans and freshwater bodies.
Recent advancements involve enhancing photocatalyst materials to increase efficiency. Techniques such as doping with metals, forming heterojunctions, and integrating catalysts into membranes are improving their light absorption and interaction with plastic waste.
While earlier research focused on laboratory tests, the field is now expanding into multidisciplinary studies that also consider environmental impacts, the nature of degradation byproducts, and the safety of residual materials. Key concerns include the cost of scaling up these technologies, maintaining catalyst durability in real-world conditions, and ensuring the complete breakdown of plastic particles.
The study also found growing interest in combining photocatalysis with other advanced treatment systems to improve plastic waste removal. Efforts are now directed at integrating these technologies into broader circular economy strategies that can help manage plastic waste sustainably.
The authors called for more partnerships between developed and developing countries to make these technologies affordable and widely available, especially in regions heavily affected by plastic pollution. The research points to a promising future where sunlight-powered photocatalysis could play a major role in global plastic waste management.