Stackable nickel–cobalt@polydopamine nanosheet based photothermal sponges for highly efficient solar steam generation

Ni₁Co₃@PDA nanosheets were utilized as photothermal materials in a kerosene lamp-like evaporator for solar steam generation. A high evaporation rate of 2.42 kg m⁻² h⁻¹ with a corresponding energy efficiency beyond the theoretical limit was achieved.