Porous graphitic carbon produced from waste coffee grounds (WCG), enormous amounts of which are generated and thrown away worldwide every year, is demonstrated as an effective broadband solar photoabsorber with a large surface area for water evaporation via an environmentally friendly and cost-efficient way. A WCG-based solar desalination device on a wood substrate exhibited an average evaporation rate of similar to 1.45 kg/m(2) h and a solar-to-vapor conversion efficiency of similar to 82.7% under 1 sun illumination. The combination of particulate photoabsorbers with a polyvinylidene fluoride binder resulted in much higher stability and produced a hydrophobic surface with antifouling effects and strong adhesive properties, which make particulate photoabsorbers washable. As a result, there was no noticeable decline in performance after 40 repeated cycles, and the devices retained 94% of initial performance after 6 h of operation in long-term tests. Ultimately, the WCG and binder material-based device suggest a straightforward approach to highly stable and efficient solar desalination at low cost.