Superior solar water purification achieved by the excellent photothermal conversion and thermal management of porous plasmonic TiN nanoparticles

•Porous plasmonic TiN NSs are successfully prepared through a two-step method.•The TiN NSs have large specific surface area and very good hydrophilicity.•The TiN NSs have stronger light absorption and better thermal management.•TiN NS-based film exhibit reflectance smaller than ∼ 19% in the entire solar spectrum.•The TiN NSs give a water evaporation rate of 1.68 kg m-2h−1 under AM 1.5.