Spent coffee grounds derived vertically aligned dual-network PVA-based hydrogel for solar desalination and dye wastewater remediation

This dataset contains the original experimental figures and raw data supporting the research entitled *Spent coffee grounds derived vertically aligned dual-network PVA-based hydrogel for solar desalination and dye wastewater remediation*. The dataset includes the following contents: 1. Morphological characterization images of the fabricated hydrogel evaporator, presenting the vertically aligned hierarchical porous structure and CS/PVA dual-network microstructure. 2. Photothermal performance test results, including solar absorption spectra, evaporation rate curves and solar-to-vapor efficiency calculation data under 1 sun irradiation. 3. Long-term salt resistance evaluation data, containing continuous evaporation stability tests in high-salinity brine and natural seawater, as well as salt crystallization observation results. 4. Outdoor on-site experimental data, including daily freshwater yield statistics and major ion removal efficiency measurements. 5. Dye wastewater remediation test data, including dye removal efficiency and cyclic stability results. All data are original experimental results generated in this study. They can be used to reproduce the experiments, verify the research conclusions, and provide reference for subsequent studies on biomass-derived photothermal materials and solar-driven water treatment technologies.