Decoration of Two‐Dimensional Cus Nanoflakes on Graphitic Carbon Foam Derived from Waste Plastic for Interfacial Solar Desalination

Interfacial solar desalination using plasmonic metal semiconductors is a valuable process for freshwater production. However, the design of a sustainable and efficient photothermal evaporator is still challenging. In the present research, polyethylene terephthalate waste bottles were upcycled into carbon foam (CF) and further functionalized with CuS nanoflakes as a photothermal layer. Analytical characterizations (X‐ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy, and scanning transmission electron microscopy–high‐angle annular dark field) demonstrated the successful decoration of two‐dimensional Covellite CuS nanoflakes on graphitic CF having microporous channels. UV/vis spectroscopy measurements show enhanced optical absorption with CuS/CF of up to 95% compared to bare CF (72%). The photothermal desalination experiment displayed an improved evaporation rate of 1.90 kg m −2 h −1 for the CuS–CF compared to 1.58 kg m −2 h −1 for the bare CF and CuS 1.41 kg m −2 h 1 , reveling the excellent water evaporation efficiency of 91%. The obtained results suggested that the design of CuS‐functionalized CF derived from waste plastic for solar desalination is a useful strategy to produce fresh water from the upcycling of waste materials and a good example of circular economy through the development of engineered composite systems.