The rapid removal of organic dyes from water under low temperature environment offers significant advantages when water purification is required in cold regions. In this work, porous lanthanum hexaboride (LaB6) nanoparticles were fabricated via a facile low-temperature molten metal (LTMM) method in Zn media under argon atmosphere. As is evidenced by the characterization results, porous LaB6 can be prepared at 400 degrees C. Elevated reaction temperature led to the growth of nanoparticles, serious aggregation and the residue of Zn element in the final product. Notably, LaB6 nanoparticles prepared at 600 degrees C by such a LTMM method presented ultrafast adsorption, with a maximum MB sorption capacity of 606.2 mg.g(-1), which was competitive with most of reported sorbents. Owing to the photothermal conversion property, LaB6 powder not only accelerated the melting of iced MB solution, but also achieved the efficient adsorption of MB in cold weather. LaB6 nanoparticles could be used as an attractive sorbent for dye removal from contaminated water, because of its facile synthesis process, excellent sorption performance and photothermal conversion property. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.