Researchers at Koç University have developed a light-driven method to produce porous semiconducting polymers under ambient conditions without the need for metal catalysts. The study, led by Prof. Dr. Önder Metin from the Department of Chemistry, in collaboration with Dr. Melek Sermin Özer, Dr. Zafer Eroğlu, and Prof. Dr. Sermet Koyuncu, was published in Nature Communications.
Porous semiconducting organic polymers have attracted growing attention due to their high thermal and chemical stability, as well as their tunable structures. With a high density of molecular-scale pores, these materials exhibit strong charge transport and light-harvesting capabilities, making them promising for applications ranging from gas storage and energy technologies to photocatalysis and optoelectronics.
However, conventional synthesis methods are often complex, costly, and difficult to scale. They typically require high temperatures, expensive metal catalysts, and multi-step reaction processes, limiting their broader applicability.
To overcome these challenges, the research team developed a visible-light-driven approach that enables the synthesis of porous semiconducting polymers under mild conditions. The method eliminates the need for precious metal catalysts and allows for more controlled formation of polymer structures, offering a more sustainable and efficient production route.
The conceptual foundation of the study lies in reinterpreting classical chemistry through a modern perspective. As Dr. Melek Sermin Özer explains,
“With this method, we revisited two-century-old diazonium chemistry—a functional group featuring a triple bond between two nitrogen atoms—and reinterpreted it within the framework of modern polymer science, introducing a distinctive approach to the field.”
A light-driven chemical process
In this approach, a two-dimensional semiconducting material known as bismuthene, synthesized by the research team, acts as a photocatalyst. When activated by visible light, it initiates electron transfer processes that drive the formation of polymer chains from selected monomers.
This mechanism enables the stepwise assembly of long and well-defined polymer networks. The resulting polymers achieve molecular weights beyond those typically accessible with conventional methods, while also allowing precise control over their structural features.
The study further demonstrates that halogen atoms such as bromine and iodine—typically difficult to incorporate using traditional synthesis methods—can be directly integrated into the polymer backbone. These elements play a key role in tuning the electronic and optical properties of the materials, enhancing their interaction with light.
Emphasizing the importance of molecular design, Dr. Zafer Eroğlu notes:
“By modifying the monomer structure, we can enable these polymers to efficiently utilize specific regions of the solar spectrum. This significantly expands their potential applications, from medicine to electronics.”
Materials that convert light into chemical energy
The researchers also demonstrated the photocatalytic performance of the synthesized polymers under visible light. In experimental studies, the materials were used in a light-driven oxidation reaction, converting styrene into benzaldehyde—an industrially valuable compound—with high efficiency and selectivity.
In some cases, both conversion rates and selectivity exceeded 99%. This performance is linked to the polymers’ ability to generate highly reactive singlet oxygen under light irradiation, a key species in many photochemical processes.
Why it matters
Porous semiconducting polymers represent one of the fastest-growing areas in materials science, yet their production often depends on costly materials and energy-intensive processes.
The method developed in this study provides a sustainable alternative by enabling synthesis under ambient conditions using visible light. Combined with their strong performance in light-driven chemical reactions, these materials hold promise for applications in sustainable chemistry, energy conversion technologies, photocatalysis, and environmental remediation.
According to the researchers, this approach opens a new pathway for designing light-responsive functional materials and advancing the development of next-generation porous semiconducting polymers.