*2.1. Materials*

Graphite powder is purchased from Tianjin Dengke Chemical Reagent Co, Ltd. (Tianjin, China), H2SO4, KMnO4 and H2O2 are obtained from Aldrich, Deionized water, selfmade in the laboratory, non-woven fabric is provided by Hainan Xinglong Nonwoven Company (Hainan, China).

#### *2.2. Preparation of Graphene Oxide (Go)*

GO is synthesized by the modified Hummers methods [28–30]. Graphite (1 g) are mixed in 23 mL H2SO4, and the mixture is stirred for 2 min in an ice bath at a temperature less than 20 ◦C. Then, add 3 g KMnO4 and stir for 3 h. The ice bath is then removed, and the mixture is stirred at 35 ◦C for 8 h. Next, 100 mL water is dropped gently. It is then diluted with 50 mL water and 5 mL H2O2. The mixture is washed with HCl (5%) and deionized (DI) water and centrifugation, freeze-drying to obtain samples.

#### *2.3. Preparation of rGO-Based Nonwoven Fabric Membrane (RGM)*

First, 0.05 g graphite oxide be dispersed in 10 mL DI water by sonication for 1 h to make an aqueous dispersion. Cut a round non-woven fabric into graphene oxide solution, taking it out, and by centrifugation, removing the excess graphene oxide, and cycling it several times. Then, the non-woven membrane loaded with GO was placed in an oven at 180 ◦C and reacted for 5 h to obtain RGM photothermal membrane [31].
