The Biochar Derived from Carp for High-Efficiency Solar Steam Generation and Water Purification

Efficient utilization of solar energy to generate steam is a green and promising technology because of its great potential applications in seawater desalination and industrial wastewater purification. However, the practical application of high-efficiency solar steam generation devices is largely overshadowed due to their complex process, high cost, low life-span, and poor thermal performance. Here, novel meat and bonemeal biochar (MBB) with high solar steam generation efficiency is produced by pyrolyzing dead carp at 300, 400, and 500 °C under anoxic conditions. Attributed to its typical hydrophilic pore structure, the photon trapping ability of MBB500 is up to 97% and 84.1% in the ultraviolet and visible regions and near-infrared light regions, respectively. Meanwhile, hydrophilic pore structural provides a strong capillary force for the rapid transmission of water. As a result, under 1 sun illumination (1 kW m^-2), the water evaporation rate and the apparent energy conversion efficiency of MBB500 reach 1.48 kg m^-2 h^-1 and 131.2%, respectively. In addition, MBB500 also exhibits excellent seawater and heavy metal wastewater evaporation effects, providing a new manufacturing strategy for photo-thermal materials, which greatly benefit their practical application in pure water regeneration.