Solar selective absorbing coating, preparation method of solar selective absorbing coating and photothermal conversion device

The invention provides a solar selective absorbing coating, a preparation method of the solar selective absorbing coating and a photothermal conversion device. The preparation method comprise the following steps that (1) an infrared reflecting layer is prepared on a substrate; (2) the surface of the infrared reflecting layer is coated with spin-coating liquid in a spin-coated mode, and an absorbing coating is obtained, wherein the spin-coating liquid is obtained by mainly mixing a polyvinyl alcohol aqueous solution and/or a phenolic resin ethanol solution and a graphene material; and (3) an antireflection layer is prepared on the absorbing layer, and the solar selective absorbing coating is obtained. The adhesive force of the graphene material layer of the solar selective absorbing coating obtained through the preparation method is remarkably improved, the binding force between the layers is high, the preparation process is simple and easy to control, the film forming speed is high, the compactness uniformity is good, solar absorptivity rate is high, the solar emissivity is low, the thermal stability is good, the heat transfer efficiency is high, and the solar selective absorbing coating is suitable for large-scale application.