Full Bagasse Bio-Waste Derived 3D Photothermal Aerogels for High Efficient Solar Steam Generation

Abstract

Nowadays, freshwater shortage, energy crisis and environmental pollution are the three major threats to human beings. Herein, we develop a photothermal material based on bagasse for solar steam generation to relieve freshwater crisis and mitigate environmental pollution caused by bio-waste. The mainly functional part of the solar driven steam generator in this paper is bagasse-based photothermal aerogel (B-PTA), which composes of carbonized bagasse (CB) and bagasse-derived cellulose fiber (BDCF). The B-PTA with CB can effectively absorb solar (~95%) and has an excellent light-to-heat ability. The B-PTA with DBCF has super-hydrophilicity, water transport and retention ability. Depending on the excellent light absorption and 3D water passageway, the B-PTA gives a water evaporation rate of 1.36 kg m–2 h–1, and can achieve a photothermal conversion efficiency of 77.34% under 1-sun illumination (1 kW m–2). The B-PTA has excellent stability that the efficiency without significant decrease after 20 cycles. In addition, the B-PTA can effectively desalt seawater and purify dye wastewater with natural sunlight. Therefore, turning bio-waste into valuable photothermal material for solar steam generation is possible. Due to the merits of low cost, scalability, environmental friendliness, B-PTA has the potential for real-world water purification.