Co‐Hydrothermal Carbonization of Cotton Stalks and MnO2 for Direct Solar Steam Generation with High Efficiency. Issue 2 (19th December 2021)

• Record Type: Journal Article
• Authors: Wang, Shuai; Deng, Hui; Chang, Hanyu; Li, Yangyang; Hui, Huanhuan; Dong, Zhenfei; Pu, Peng
• Is Part Of: Solar RRL. Volume 6:Issue 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-19
• Subjects: carbon dots -- co-hydrothermal carbonization -- cotton stalks -- MnO2 -- recirculation -- solar team generation; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202100890
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Biomass‐based photothermal materials for solar steam power generation have been a recent research hotspot. However, despite the many research advances that have been made, many challenges remain. For example, high temperature carbonization leads to the loss of hydrophilicity, the surface coating is easy to peel off, hydrothermal carbonization (HTC) does not guarantee the photothermal performance, and hydrothermal carbonization fluid (HTC‐F) is difficult to handle. Herein, a new material (H‐CS/MnO2 ) is prepared by co‐hydrothermal carbonization of cotton stalks (CS) and MnO2, and a stable and effective evaporation system is designed. While both ensure super hydrophilicity, the stable loading of MnO2 leads to an excellent photothermal performance. Experimental results show that H‐CS/MnO2 reaches 93.46% evaporation efficiency and the evaporation rate can reach 2.43 kg m −2 h −1 under 1 sun. Moreover, by means of recycling, not only the treatment of HTC solution is solved, but also the carbon dots are continuously enriched and exhibit certain photothermal effects during the recycling process. In addition, H‐CS/MnO2 exhibited excellent salt resistance and corrosion resistance. The obtained condensate heavy ion concentration removal rate reached more than 99.9%. Therefore, the H‐CS/MnO2 fabricated herein has the possibility of practical application in the future. Abstract : Herein, photothermal materials by cohydrothermal carbonization of cotton stalks and MnO2 are prepared. They have excellent photothermal performance, evaporation efficiency up to 2.43 kg m −2 h −1, with outstanding stability. Carbon dots (CDs) are found through cycling of hydrothermal carbonization fluid. CDs and MnO2 act synergistically to improve the evaporation efficiency of the material up to 2.85 kg m −2 h −1 .