Lignin-Supported Heterogeneous Photocatalyst for the Direct Generation of H 2 O 2 from Seawater

• Published in: Journal of the American Chemical Society 2022-02, Vol.144 (6), p.2603-2613
• Main Authors: Gopakumar, Aswin, Ren, Peng, Chen, Jianhong, Manzolli Rodrigues, Bruno Vinicius, Vincent Ching, H Y, Jaworski, Aleksander, Doorslaer, Sabine Van, Rokicińska, Anna, Kuśtrowski, Piotr, Barcaro, Giovanni, Monti, Susanna, Slabon, Adam, Das, Shoubhik
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.1c10786

The development of smart and sustainable photocatalysts is in high priority for the synthesis of H O because the global demand for H O is sharply rising. Currently, the global market share for H O is around 4 billion US$ and is expected to grow by about 5.2 billion US$ by 2026. Traditional synthesis of H O via the anthraquinone method is associated with the generation of substantial chemical waste as well as the requirement of a high energy input. In this respect, the oxidative transformation of pure water is a sustainable solution to meet the global demand. In fact, several photocatalysts have been developed to achieve this chemistry. However, 97% of the water on our planet is seawater, and it contains 3.0-5.0% of salts. The presence of salts in water deactivates the existing photocatalysts, and therefore, the existing photocatalysts have rarely shown reactivity toward seawater. Considering this, a sustainable heterogeneous photocatalyst, derived from hydrolysis lignin, has been developed, showing an excellent reactivity toward generating H O directly from seawater under air. In fact, in the presence of this catalyst, we have been able to achieve 4085 μM of H O . Expediently, the catalyst has shown longer durability and can be recycled more than five times to generate H O from seawater. Finally, full characterizations of this smart photocatalyst and a detailed mechanism have been proposed on the basis of the experimental evidence and multiscale/level calculations.