Search

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., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Due to white pollution related environmental concern and sustainable development requirement, it is desirable to recycle the widely used plastic wastes into products with commercial value, such as high-valued carbon materials which can be applied in electrochemical fields. In this work, porous carbon flakes (PCFs) are produced by direct pyrolysis of polystyrene waste through template method. Furthermore, manganese dioxide (MnO 2 ) nanosheets are selectively deposited on the surface of resultant PCFs to form hybrid (PCF-MnO 2 ). Because of the large specific surface area (1087 m 2 /g) and high conductivity of PCFs, native high specific capacity of MnO 2 , and positive synergistic interaction between PCF and MnO 2 , the resulting hybrid materials show an ultrahigh capacitance of 308 F/g at 1 mV/s and 247 F/g at 1 A/g in LiCl electrolyte, and excellent cycle stability of 93.4% capacitance retention over 10,000 cycles at 10 A/g in symmetric supercapacitor device. This work demonstrates a convenient method for the preparation of cost-effective and high-performance electrode material for electric capacitor. More importantly, it provides a potential way to recycle polystyrene waste into high-valued product in large-scale with disposing of polymeric waste to alleviate environmental concerns., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Due to the ever-increasing plastic waste causing serious environmental problems, it is highly desirable to recycle it into high-value-added products, such as carbon nanomaterials. However, the traditional catalytic carbonization of hydrocarbon polymers is severely prohibited by the complexity of real-world plastic waste due to the existence of halogen-containing polymers. In this study, through a universal combined template based on magnesium oxide and iron(III) acetylacetonate (Fe(acac)3), a three-dimensional hollow carbon sphere/porous carbon flake hybrid nanostructure is prepared from carbonization of plastic waste with high yields (>70 wt%). This approach is not only suitable for hydrocarbon polymers, but also for halogen-containing polymers. Interestingly, the obtained advanced carbon framework exhibits excellent performance in lithium-ion batteries (802 mA h g−1 after 500 cycles at 0.5 A g−1). The present research paves a new avenue to upcycle plastic waste into a high value-added product. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Porous carbon prepared from freeze-dried date sheets. • Porous carbon exhibits an effective pore size distribution in 0.7–0.9 nm. • Porous carbon is used as adsorbents for CO 2 in various temperature and pressure. • This work provides a practical way to develop cost-effective adsorbents. Abstract This work reports a selective chemical activation method for the controllable synthesis of porous carbons with pore sizes ranging from micropores to hierarchical micro/mesopores from date sheets. Through selectively controllable carbonization and combined activation processes, the as-prepared carbon materials exhibit a high specific surface area (3337 m2/g) mainly derived from ultra-micropores in the range of 0.7–0.9 nm, which majorly contributes to CO 2 storage at a low pressure. Among the activated carbon materials prepared, ACDS-800-4 exhibits the highest CO 2 adsorption capacity (that is, 4.36 mmol/g at 25 °C and 1 bar, and 6.4 mmol/g at 0 °C and 1 bar), a good recyclability and selectivity. ACDS-800-6 exhibits a higher CO 2 adsorption capacity of 22 mmol/g at 25 °C and a high pressure of 40 bar. This work demonstrates that the pore size is key to the CO 2 storage at lower pressures while specific surface area plays an important role under high pressure adsorption process. Since these efficient microporous carbons are synthesized from biomass, this work provides a potential way to develop cost-effective adsorbents for removing CO 2 at both low and high pressures and various temperatures. [ABSTRACT FROM AUTHOR]