Durable, scalable and affordable iron (III) based coconut husk photothermal material for highly efficient solar steam generation

• Published in: Desalination Vol. 518; p. 115280
• Main Authors: Pham, Tien Thanh, Nguyen, Thanh Huyen, Nguyen, Thi An Hang, Pham, Dinh Dat, Nguyen, Duc Cuong, Do, Danh Bich, Nguyen, Hoai Viet, Ha, Minh Hiep, Nguyen, Zoom Hoang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2021
• Subjects: Biomass-based photothermal materials; Coconut fiber; Coconut husk; Seawater desalination; Solar vapor generation; Biomass-based photothermal materials; Coconut fiber; Coconut husk; Seawater desalination; Solar vapor generation
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2021.115280

Biomass-based photothermal materials, being fabricated based on agricultural waste, are widely applied in solar steam generation (SSG) recently. The evaporation rate of the SSG systems while utilizing these materials can reach 1.4–1.6 kg m-2 h-1 under 1 sun condition. In this study, a coconut husk (CH), a common agricultural waste, was utilized to fabricate the photothermal material that can be applied in the SSG system. CH consists of coconut fibers containing many vascular bundles with 10-20 μm diameter and cocopeat that has honeycomb-like structure. After treating CH with tannic acid and Fe (III) solution, the coordination of phenolic compounds with Fe3+ in the CH is formed. The resulting CH-TA-Fe3+ (CHP) material demonstrated significant advantages such as high light absorption, low thermal conductivity, ultra-fast water transportation, low moisture enthalpy, and self-cleaning properties. The CHP-based SSG system possessed high seawater evaporation rate (1.83 kg m-2 h-1) and evaporation efficiency (73.2%), which are comparable to those in the previous studies on biomass material based SSG systems. Especially, the CHP-based SSG system exhibited excellent structural stability that ensures their long-term performance in the seawater desalination. With simple fabrication process, affordable price, and eco-friendly materials, the CHP proves great potential in seawater desalination application. [Display omitted] •A scalable and affordable coconut husk is used as photothermal material for efficient desalination.•The photothermal material exhibits many advantages, such as moisture enthalpy, low thermal conductivity.•The solar evaporator demonstrates an evaporation rate of 1.83 kg m−2 h−1 and an efficiency of 73.2% under 1 sun.•The material has excellent structural stability in seawater during the desalination process．