1：Experimental Design and Method Selection:

The study involves preparing a bi-layer system (CSS-film) by daubing carbon particles on a sintered sawdust film (SS-film) with adjustable porosities. The influence of porosity on water diffusivity, thermal conductivity, and evaporation performance is explored through controlled experiments under solar illumination.

2：Sample Selection and Data Sources:

Sawdust from pine wood is used to create SS-films with porosities ranging from 0.2 to 0.7 by varying manufacturing pressures. Carbon particles are derived from high-temperature carbonization of discarded wood. Data include SEM images, FTIR and XPS spectra, absorption spectra, thermal conductivity measurements, and evaporation mass changes.

3：2 to 7 by varying manufacturing pressures. Carbon particles are derived from high-temperature carbonization of discarded wood. Data include SEM images, FTIR and XPS spectra, absorption spectra, thermal conductivity measurements, and evaporation mass changes. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment includes vacuum tube furnace (GSL1600X), planetary ball mill (DECO-PBM-V-2L-A), ultrasonic cell crusher (JY92-IIN), SEM (Quanta 250), FTIR spectrometer (VERTEX 80v), XPS instrument (ESCALAB 250Xi), UV-VIS-NIR spectrophotometer (Lambda 750S), thermal conductivity meter (TC3000), solar illumination simulator (Newport AM 1.5), electronic microbalance (OHAUS CP224C), data acquisition instrument (Keithley 2700), IR camera (FLUKE ti9), and LA-ICP-MS (NWR213-7900). Materials include sawdust, carbon particles, deionized water, and simulated seawater (3.5% NaCl solution).

4：5), electronic microbalance (OHAUS CP224C), data acquisition instrument (Keithley 2700), IR camera (FLUKE ti9), and LA-ICP-MS (NWR213-7900). Materials include sawdust, carbon particles, deionized water, and simulated seawater (5% NaCl solution). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Preparation involves cold-pressing sawdust into S-films, sintering to form SS-films, and daubing carbon particles to create CSS-films. Evaporation tests are conducted under 1 sun illumination, with mass changes, temperatures, and energy losses measured. Wettability and thermal conductivity are characterized for different porosities.

5：Data Analysis Methods:

Evaporation rate and efficiency are calculated using mass change and energy balance equations. Thermal conductivities are analyzed with mixing rules. Statistical analysis of particle sizes uses ImageJ software. Energy losses are estimated using Fourier's law, Stefan-Boltzmann law, and Newton's law of cooling.