Recycling Waste Toner Constructed Photothermal Membrane for Highly Efficient Solar-Driven Interfacial Evaporation

Superseded toner cartridges in printers often contain abundant residual toner during the replacement. These toners contain resins, Fe3O4, and SiO2 particles. Waste toner disposal results in resource wastage and solid waste accumulation. Thus, several methods have been proposed for the high-value-added conversion of waste toners. However, the photothermal conversion ability of toners and its application in solar-driven interfacial evaporation have not yet been explored. Herein, waste toner was recycled via high-temperature calcination and acid etching, which yielded two novel photothermal materials, namely HTC-T and HA-T. The light absorption capacity of HA-T reached 96.84%, and the evaporation rates of methanol, ethanol, isopropanol, water, N,N-dimethylformamide, and N-methyl pyrrolidone under 1 sun irradiation of HA-T membranes were 6.07, 5.95, 6.71, 2.15, 3.74, and 1.49 kg·m–2·h–1, respectively. Moreover, HCT-T and HA-T were able to degrade up to 99.99% of methyl orange, methylene blue, and rhodamine B solutions at a concentration of 20 ppm. This study thus provided a recovery technique for waste toner that realized the recycling of solid waste resources with environmental and economic benefits.