MIL-53(Al) assisted in upcycling plastic bottle waste into nitrogen-doped hierarchical porous carbon for high-performance supercapacitors.

Disposable aluminum cans and plastic bottles are common wastes found in modern societies. This article shows that they can be upcycled into functional materials, such as metal-organic frameworks and hierarchical porous carbon nanomaterials for high-value applications. Through a solvothermal method, used poly(ethylene terephthalate) bottles and aluminum cans are converted into MIL-53(Al). Subsequently, the as-prepared MIL-53(Al) can be further carbonized into a nitrogen-doped (4.52 at%) hierarchical porous carbon framework. With an optical amount of urea present during the carbonization process, the carbon nanomaterial of a high specific surface area of 1324 m ²  g ^-1 with well-defined porosity can be achieved. These features allow the nitrogen-doped hierarchical porous carbon to perform impressively as the working electrode of supercapacitors, delivering a high specific capacitance of 355 F g ^-1 at 0.5 A g ^-1 in a three-electrode cell and exhibiting a high energy density of 20.1 Wh kg ^-1 at a power density of 225 W kg ^-1 , while simultaneously maintaining 88.2% capacitance retention over 10,000 cycles in two-electrode system. This work demonstrates the possibility of upcycling wastes to obtain carbon-based high-performance supercapacitors.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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