Turning Trash to Treasure: The Influence of Carbon Waste Source on the Photothermal Behaviour of Plasmonic Titanium Carbide Interfaces

Pyrolysis of carbonaceous waste material has become an attractive method of recycling to generate value added products. Alongside pyrolytic oil and gas fractions, the thermal degradation forms solid pyrolytic char, which can be further processed. Local waste materials, including birch wood residue (BW), Reynoutria japonica stems (KW), spent coffee grounds (CG), tire rubber (TR), and lobster shells (LS) we assessed to form pyrolytic char. Using a simple acid treatment step on the chars, this study has shown successfully incorporate many of them into the low-temperature synthesis of plasmonic TiC NPs. Each char was shown to display distinctive physical and chemical characteristics, which was exploited to synthesize TiC NPs with unique properties. To study the plasmonic behaviour of each TiC sample, solar driven desalination experiments were conducted. TiC formed from TR char achieved broadband absorbance of ~95 % of the solar spectrum, reaching a near-perfect solar-to-vapor generation efficiency of 95 %, or a water generation rate of 1.40±0.01 kg m^-2 h^-1 under one-sun illumination. This makes it the best performing of all chars tested, and among the top performers reported in the literature to date. The evaporators maintain activity over time and under strongly hypersaline conditions.