Mesoporous activated carbons with enhanced porosity by optimal hydrothermal pre-treatment of biomass for supercapacitor applications

Hydrothermal Carbonization: Modeling, Final Properties Design and Applications: A Review

“…A review of the research in this field shows that KOH is, by far, the most used activating agent for enhancing porosity development in HCs in order to improve their supercapacitor performance [98][99][100][101][102], providing a better porosity develpment as compared to other chemical agents such as H 3 PO 4 or NaOH [103]. This compound can successfully develop the HC incipient porosity by means of the Reaction (1), followed by K 2 CO 3 decomposition into K 2 O or its reaction with carbon.…”

“…[101] studied the HTC of coconut shell in the presence of ZnCl 2 and H 2 O 2 and found that both temperature and ZnCl 2 concentration influenced the amount of oxygen groups formed on the HC; this, in turn, facilitated Zn 2+ access to the precursor surface, which led to better dehydration of the biomass and in definitive enhanced mesopore formation by subsequent chemical activation. Greater concentrations were beneficial for solid yield and oxygen functional group formation, up to a maximum, which was associated with limited solubility at higher concentrations.…”

Hydrothermal conversion of biomass waste to activated carbon with high porosity: A review

“…The important ro solubility of ZnCl 2 and thus its effect on the mesoporosity formation in the activated carbons was reported[44]. Jain et al further investigated t ZnCl 2 and water) which governed the formation of oxygenated functional groups on hydrochar and ZnCl 2 solubility and thus its availability at the time of activation hydrothermal pre-treatment using H concentrations was employed to increase the OFG content in the hydrochar for efficient utilization of ZnCl 2[127]. Successive hydrothermal treatments using Hdifferent concentrations) resulted in up to 39% increase in BET surface area (1753 to 2440 m and up to 30% increase in mesopore area (859 to 1121 m employed.…”

Biomass‐Derived Carbon Materials as Prospective Electrodes for High‐Energy Lithium‐ and Sodium‐Ion Capacitors

“…Jain and co-workers extensively studied the utilization of coconut (Cocos nucifera)-shell-derived AC by adopting various strategies to improve their textural properties, such as high specific surfacea rea, mesoporosity,o xygenated functionalg roups,a nd pore-size distribution. [53][54][55][56][57][58][59] Coconut shell (CS) is an important type of biowaste, owing to its low ash content (ca. 2%)a nd high carbonaceous content (> 72 %).…”