New self-heating catalyst cleans antibiotic pollutants from water and soil

(Press-News.org) Scientists have developed a fast, energy-efficient method to create an iron-carbon (Fe/C) catalyst that can remove antibiotic pollutants from both water and soil by using oxygen from the air. The study, published in Sustainable Carbon Materials, introduces a self-heating synthesis approach that could pave the way for greener environmental cleanup technologies.

Antibiotic residues such as sulfamethoxazole, commonly found in wastewater and agricultural runoff, are a growing environmental concern. These contaminants persist in the environment and contribute to antibiotic resistance. To tackle this problem, researchers have been working to design catalysts that activate molecular oxygen to break down harmful chemicals without relying on added oxidants or harsh chemicals.

A team led by Xiangdong Zhu at Fudan University has developed a rapid “flash Joule heating” method that can produce highly active iron-carbon catalysts in milliseconds. This self-heating process generates temperatures of around 4,000 Kelvin, transforming simple iron and biochar precursors into a stable, conductive composite. The resulting Fe/C catalyst contains two key iron species, Fe⁰ and Fe²⁺, evenly dispersed within a partially graphitized carbon network.

“These two forms of iron work together like partners,” said Zhu. “The conductive carbon structure helps them transfer electrons efficiently, which allows oxygen molecules to transform into reactive radicals that attack pollutants.”

The Fe/C catalyst demonstrated remarkable performance in degrading sulfamethoxazole. In laboratory tests, the catalyst removed up to 94.6 percent of the antibiotic within four hours. The process works by activating molecular oxygen to produce highly reactive hydroxyl radicals (•OH) and superoxide radicals (O₂•⁻), which break down the contaminants into less harmful compounds.

Unlike conventional oxidation systems that require hydrogen peroxide or other external oxidants, this new approach relies solely on molecular oxygen, making it more environmentally friendly and cost-effective. The catalyst also showed excellent adaptability, maintaining strong degradation performance under a range of pH conditions and in complex soil environments.

“The material’s robustness across different water and soil conditions suggests it can perform well outside the laboratory,” Zhu explained. “That is a critical step toward real-world applications.”

Further experiments revealed how the catalyst’s structure and synthesis conditions affect its performance. Higher voltages during the self-heating process produced more reactive iron species and improved pollutant degradation. Detailed spectroscopy and radical trapping tests confirmed that the reaction proceeds through multiple pathways, primarily through hydroxyl radicals with additional contributions from superoxide radicals.

The research team believes this work offers new insights for designing next-generation catalysts for environmental remediation. By understanding how rapid self-heating influences the chemical structure and reactivity of iron-carbon materials, scientists can develop scalable solutions for cleaning up antibiotics, pesticides, and other emerging pollutants.

“This self-heating strategy is fast, simple, and adaptable,” said Zhu. “It points to a sustainable way to turn ordinary carbon materials into powerful tools for protecting our water and soil.”

The study, titled “Rapid self-heating synthesis of Fe/C composites for molecular oxygen activation toward organic contaminant degradation,” was supported by the National Natural Science Foundation of China.

 

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Journal reference: Jia C, Li A, Shang H, Jiang Y, Zhang J, et al. 2025. Rapid self-heating synthesis of Fe/C composites for molecular oxygen activation toward organic contaminant degradation. Sustainable Carbon Materials 1: e005 

https://www.maxapress.com/article/doi/10.48130/scm-0025-0006  

 

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About Sustainable Carbon Materials:

Sustainable Carbon Materials is a multidisciplinary platform for communicating advances in fundamental and applied research on carbon-based materials. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon materials around the world to deliver findings from this rapidly expanding field of science. It is a peer-reviewed, open-access journal that publishes review, original research, invited review, rapid report, perspective, commentary and correspondence papers.

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