Carbonized Fast-Growing Bamboo as a Photothermal Device for Efficient Solar Vapor Generation

Abstract

Solar steam generation is an effective method for solving the freshwater shortage problem. In this study, porous carbonized bamboo (CB) was prepared through high-temperature (700 °C) carbonization under an argon atmosphere for efficient solar steam evaporation. The vertical porous structure of natural bamboo was retained after carbonization for water transportation. Moreover, carbonized bamboo could effectively enhance the degree of graphitization, which is conducive to the absorption of sunlight. According to the results of analysis test, it was obvious that the carbonized bamboo (CB-700) possessed excellent solar energy evaporation potential. The evaporation rate was up to 2.034 kg m–2 h–1 under 1 sun illumination and its solar absorption was averagely 90% in the range of 500–2500 nm. Moreover, the thermal conductivity coefficients of CB-700 and bamboo were 0.1964 and 0.2374 W m–1 K–1, respectively. Owing to this excellent local heat concentration, the surface temperature of CB-700 could achieve 73 °C under 7 sun illumination. Additionally, the material demonstrated an excellent desalting effect on seawater with satisfactory mechanical stability. Thus, the readily available carbonized bamboo can be potentially applied for solar steam generation.