Solar-driven interfacial evaporation technology presents a promising approach for large-scale, sustainable water resource utilization, with significant potential in seawater desalination and wastewater treatment. However, the simultaneous removal of waterborne pollutants during solar interfacial evaporation remains a significant challenge. This study introduces an all-natural photothermal hydrogel composed of chitosan, cellulose nanofibers, and carbonized spent bleaching earth (C@SBE) for efficient seawater desalination and heavy metal remediation. The hydrogel performance was enhanced by optimizing its three-dimensional porous structure and incorporating C@SBE to improve photothermal conversion efficiency and adsorption capacity. Under one-sun irradiation, the hydrogel achieved an impressive evaporation rate of 2.17 kg m