Nickel-substituted polyoxometalate-CdS single-cluster photocatalysts for efficient plastic waste degradation coupled with H2 production

Plastic waste management is a critical global challenge, with less than 10% of annual plastic production being recycled. Traditional methods like incineration and landfilling pose environmental risks, prompting scientists to explore photocatalytic alternatives. A team led by Prof. Zhi-Ming Zhang has now developed a groundbreaking Ni-POM@CdS catalyst that addresses this issue by coupling plastic waste (polylactic acid, PLA) degradation with hydrogen (H₂) production—a clean energy source.

The team published their research result in Polyoxometalates on July 28, 2025.

This study reveals why the Ni-POM@CdS composite catalyst exhibits substantially higher H₂ evolution activity than pristine CdS. The secret lies in the Ni-POM clusters’ “electron sponge” effect, which significantly improves the separation and migration efficiency of the photogenerated carriers in CdS, thereby increasing the surface hole concentration. By anchoring atomically precise Ni-POM clusters onto CdS, we’ve created a system where electrons drive H₂ production while holes oxidize PLA into useful chemicals.

The team’s impregnation method ensures uniform dispersion of Ni-POM clusters (1.4–2.0 nm) on CdS nanospheres, as confirmed by HRTEM and elemental mapping. XPS and PL spectroscopic analyses demonstrated that among all Ni-POMs examined, Ni₉ possesses the most pronounced capability for rapid electron capture, effectively reducing charge recombination while simultaneously extending hole lifetimes for plastic oxidation. Notably, the Ni₉@CdS-10 catalyst exhibits a remarkable 160-fold enhancement in H₂ evolution activity compared to pristine CdS, while maintaining excellent stability over 50 hours of continuous operation without observable structural degradation.

This work addresses two critical challenges simultaneously: waste valorization and renewable energy production, the process generates pyruvate as a valuable byproduct, enhancing its economic feasibility. The research team plans to scale the technology for practical applications, including microplastic remediation in limnetic environments and integration with photocatalytic systems for solar-driven H₂ generation.

Collaborators included researchers from Tiangong University and the Institute of General and Inorganic Chemistry of Russian Academy of Sciences. This work was supported by the National Natural Science Foundation of China (22401017).

About the Authors

Dr. Zhi-Ming Zhang is a professor at the Institute of New Energy Materials and Low-Carbon Technology, Tianjin University of Technology, China. His research focuses on controlled synthesis of clusters, catalyst@photosensitiser composite catalytic systems. Until now, he has published over 150 peer-reviewed papers, such as Nat. Synth., PANS, Natl. Sci. Rev., CCS Chem., J. Am. Chem. Soc., Angew. Chem., Nat. Commun. and Adv. Mater. with over 10000 times citations, in which 12 papers are listed as highly cited papers by ESI. He served as a member of the Youth Working Committee of the Chinese Crystallographic Society and Chinese Society for Imaging Science and Technology, the editorial board and young star editor of Chin. Chem. Lett., Current Catal., Nano Res., Smartmat, Polyoxometalates and Chin. Appl. Chem. For more information, please pay attention to his research homepage https://nem.tjut.edu.cn/Welcome_to_Zhang_Research_Group/Home.htm.

About Polyoxometalates

Polyoxometalates (ISSN 2957-9821) is a peer-reviewed (single-blind), open-access and interdisciplinary journal, sponsored by Tsinghua University. Polyoxometalates publishes original high-quality research papers and significant review articles that focus on cutting-edge advancements in Polyoxometalates, and clusters of metals, metal oxides and chalcogenides. Rapid review to ensure quick publication is a key feature of Polyoxometalates. It is indexed by ESCI, Scopus (CiteScore 2024 = 14.7), Ei Compendex, CAS, and DOAJ.