Recently, Professor Zhang Qingzhe, from the School of Environmental and Engineering of Shandong University, have developed a visible-light-response photocatalyst capable of efficiently degrading per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals”, under sunlight. The findings were published in Nature Water, entitled “Steering charge transfer in CuInS₂/BiOCl composites to enable sunlight-driven C-F bond cleavage of PFAS in water”. This paper features Master student Liu Fuyu as first author, with Professor Zhang Qingzhe, Professor Liu Runzeng from Shandong University, Professor Duan Xiaoguang from the University of Adelaide, and Professor Chen Zongwei from Zhengzhou University as co-corresponding authors.

PFAS has been widely used in industries such as semiconductor manufacturing, food packaging, and firefighting foams due to their exceptional chemical stability and amphipathicity. However, the strong C-F bonds that make them useful also render them highly persistent in the environment, posing significant risks to ecosystems and human health. Conventional treatment methods struggle to break these bonds effectively. Inspired by the electron transfer chain in natural photosynthesis, the team designed a Z-scheme heterojunction photocatalyst by coupling BiOCl nanoplates with CuInS₂quantum dots (QDs) via inorganic S^2-ligands. This structure generates a built-in electric field at the interface, which precisely directs the migration of photogenerated charge carriers. Electrons are retained in the CuInS₂QDs with strong reducing power to cleave C-F bonds, while holes accumulate in BiOCl with strong oxidizing power to break carbon chains.

The CuInS₂/BiOCl heterojunction achieved outstanding performance in the photocatalytic degradation of PFAS. Under ultraviolet irradiation, the system reached a defluorination efficiency of 75.8% and a total organic carbon removal efficiency of 76.8% for sodium p-perfluorous nonenoxybenzenesulfonate (OBS), a representative PFAS alternative. The catalyst also demonstrated broad applicability, effectively degrading a mixture of 17 representative PFAS compounds.

Combined with in-situ spectroscopy, density functional theory calculations, and high-resolution mass spectrometry, the study elucidated the electron-mediated C-F bond cleavage mechanism and proposed a detailed degradation pathway for OBS under sunlight. The team integrated the catalyst into a continuous-flow reactor. In outdoor field tests conducted under natural sunlight, the system achieved over 96% OBS removal within 10 hours, showcasing its potential for scalable, energy-efficient PFAS remediation. This work provides new physical insights into C–F bond activation under solar irradiation and enlightens the design of next-generation photocatalysts for PFAS decontamination in complex aqueous environments.

This work was collaboratively completed by Shandong University and multiple international teams including the University of Adelaide and the University of Sydney in Australia, the University of Chicago and Florida International University in the United States, Imperial College London and the University of Sheffield in the United Kingdom, INRS of Canada, the Research Center for Eco-Environmental Sciences of the Chinese Academy of Sciences, Nanjing University, and Zhengzhou University. It was supported by the National Natural Science Foundation of China, the Taishan Scholars Project Special Fund, the National Key Research and Development Program of China, Shandong Provincial Natural Science Foundation, Key R&D Program of Shandong Province, China, and other funding resources.