Poly(urethane)-based solar absorber coatings containing nanogold

► We used a solution technique to prepare solar absorber coatings containing nanogold. ► Absorber coatings were prepared via the redox reactions of HAuCl4 and Cu substrates. ► The bottom surface of the coating was abundant in nano-sized CuCl and Au. ► The performance of the coating was dependent on PU/HAuCl4 (w/w) in the solution.