scholarly journals Recycling Black Tea Waste Biomass as Activated Porous Carbon for Long Life Cycle Supercapacitor Electrodes

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6592
Author(s):  
Hojong Eom ◽  
Jooyoung Kim ◽  
Inho Nam ◽  
Sunyoung Bae
Keyword(s):  
Surface Area ◽  
Electrode Material ◽  
Storage System ◽  
Black Tea ◽  
Hydrothermal Carbonization ◽  
Waste Recycling ◽  
Large Surface Area ◽  
Waste Biomass ◽  
Activation Temperature ◽  
Tea Waste

Value creation through waste recycling is important for a sustainable society and future. In particular, biomass, which is based on crops, is a great recyclable resource that can be converted into useful materials. Black tea is one of the most cultivated agricultural products in the world and is mostly discarded after brewing. Herein, we report the application of black tea waste biomass as electrode material for supercapacitors through the activation of biomass hydrochar under various conditions. Raw black tea was converted into hydrochar via a hydrothermal carbonization process and then activated with potassium hydroxide (KOH) to provide a large surface area and porous structure. The activation temperature and ratio of KOH were controlled to synthesize the optimal black tea carbon (BTC) with a large surface area and porosity suitable for use as electrode material. This method suggests a direction in which the enormous amount of biomass, which is simply discarded, can be utilized in the energy storage system. The synthesized optimal BTC has a large surface area of 1062 m2 and specific capacitance up to 200 F∙g−1 at 1 mV∙s−1. Moreover, it has 98.8% retention of charge–discharge capacitance after 2000 cycles at the current density of 5 A∙g−1.

scholarly journals Development and Characterization of Composite Carbon Adsorbents with Photocatalytic Regeneration Ability: Application to Diclofenac Removal from Water

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Velma Beri Kimbi Yaah ◽  
Satu Ojala ◽  
Hamza Khallok ◽  
Tiina Laitinen ◽  
Marcin Selent ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Palm Kernel ◽  
Hydrothermal Carbonization ◽  
Carbon Composite ◽  
Carbon Adsorbents ◽  
Regeneration Ability ◽  
Activation Temperature

This paper presents results related to the development of a carbon composite intended for water purification. The aim was to develop an adsorbent that could be regenerated using light leading to complete degradation of pollutants and avoiding the secondary pollution caused by regeneration. The composites were prepared by hydrothermal carbonization of palm kernel shells, TiO2, and W followed by activation at 400 °C under N2 flow. To evaluate the regeneration using light, photocatalytic experiments were carried out under UV-A, UV-B, and visible lights. The materials were thoroughly characterized, and their performance was evaluated for diclofenac removal. A maximum of 74% removal was observed with the composite containing TiO2, carbon, and W (HCP25W) under UV-B irradiation and non-adjusted pH (~5). Almost similar results were observed for the material that did not contain tungsten. The best results using visible light were achieved with HCP25W providing 24% removal of diclofenac, demonstrating the effect of W in the composite. Both the composites had significant amounts of oxygen-containing functional groups. The specific surface area of HCP25W was about 3 m2g−1, while for HCP25, it was 160 m2g−1. Increasing the specific surface area using a higher activation temperature (600 °C) adversely affected diclofenac removal due to the loss of the surface functional groups. Regeneration of the composite under UV-B light led to a complete recovery of the adsorption capacity. These results show that TiO2- and W-containing carbon composites are interesting materials for water treatment and they could be regenerated using photocatalysis.

Investigation on the production of bioethanol from black tea waste biomass in the seawater-based system

2018 ◽  
Vol 4 ◽  
pp. 209-213 ◽  
Author(s):  
Dash Indira ◽  
Bhaskar Das ◽  
Harshita Bhawsar ◽  
Sahoo Moumita ◽  
Eldin Maliyakkal Johnson ◽  
...  
Keyword(s):  
Black Tea ◽  
Waste Biomass ◽  
Tea Waste

Preparation of porous cadmium sulphide on nickel foam: a novel electrode material with excellent supercapacitor performance

2016 ◽  
Vol 4 (13) ◽  
pp. 4920-4928 ◽  
Author(s):  
Panpan Xu ◽  
Jijun Liu ◽  
Peng Yan ◽  
Chenxu Miao ◽  
Ke Ye ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Area ◽  
Electrode Material ◽  
Nickel Foam ◽  
Cadmium Sulphide ◽  
Large Surface Area ◽  
Preparation Process ◽  
High Electrical Conductivity ◽  
Supercapacitor Performance ◽  
Facile Preparation

Large surface area, high electrical conductivity, and abundant channels have been recognized to favor faradic capacitors, but their realization at the same time by a facile preparation process is still a great challenge.

Ordered multimodal porous carbon with hierarchical nanostructure as high performance electrode material for supercapacitors

RSC Advances ◽  
2014 ◽  
Vol 4 (73) ◽  
pp. 38931-38938 ◽  
Author(s):  
Sudeshna Chaudhari ◽  
Seon Young Kwon ◽  
Jong-Sung Yu
Keyword(s):  
Mass Transport ◽  
Surface Area ◽  
Electrode Material ◽  
Porous Carbon ◽  
High Performance ◽  
Electrical Charge ◽  
Large Surface Area ◽  
Charge Storage ◽  
Hierarchical Nanostructure

Unique hierarchical nanostructure of OMPC facilitates fast mass transport along with large surface area for electrical charge storage.

High performance capacitive deionization using modified ZIF-8-derived, N-doped porous carbon with improved conductivity

Nanoscale ◽  
2018 ◽  
Vol 10 (31) ◽  
pp. 14852-14859 ◽  
Author(s):  
Yang Li ◽  
Jeonghun Kim ◽  
Jie Wang ◽  
Nei-Ling Liu ◽  
Yoshio Bando ◽  
...  
Keyword(s):  
Surface Area ◽  
Electrode Material ◽  
Porous Carbon ◽  
High Performance ◽  
Micropore Volume ◽  
Large Surface Area ◽  
Capacitive Deionization ◽  
Zeolitic Imidazolate Framework ◽  
Promising Electrode Material

Zeolitic imidazolate framework (ZIF) composite-derived carbon exhibiting large surface area and high micropore volume is demonstrated to be a promising electrode material for the capacitive deionization (CDI) application.

scholarly journals Discrete Coating of CNT on Carbon Fiber Surfaces and the Effect on Improving the Electrochemical Performance of VRFB Systems

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 736
Author(s):  
Zhongxu Tai ◽  
Dongying Ju ◽  
Susumu Sato ◽  
Kenzo Hanawa
Keyword(s):  
Carbon Fiber ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Liquid Flow ◽  
Electrode Material ◽  
Electrode Surface ◽  
Storage System ◽  
Small Diameter ◽  
Flow Batteries

Carbon fiber, as an electrode material, has been widely used in all-vanadium liquid flow batteries. In order to further reduce the size of the all-vanadium storage system, it is imperative to increase the current density of the battery and to achieve high conductivity and large electrostatic capacitance. The graphitization of the electrode material and the improvement in the specific surface area of the electrode surface also greatly affect the performance of all-vanadium redox liquid flow batteries. Therefore, in this paper, carbon nanotubes (CNTs) with a small diameter and a large specific surface area were coated on the electrode surface of the VRFB system by the dispersion method to improve the cell performance. The performance of the surface-modified electrode was also verified by Raman spectroscopy, XRD and SEM surface observations and charge/discharge experiments.

scholarly journals Sewage Sludge Treatment by Hydrothermal Carbonization: Feasibility Study for Sustainable Nutrient Recovery and Fuel Production

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2697
Author(s):  
Gabriel Gerner ◽  
Luca Meyer ◽  
Rahel Wanner ◽  
Thomas Keller ◽  
Rolf Krebs
Keyword(s):  
Liquid Phase ◽  
Sewage Sludge ◽  
Hydrothermal Carbonization ◽  
Economic Feasibility ◽  
Phosphorus Recovery ◽  
High Yield ◽  
Nutrient Recovery ◽  
Waste Biomass ◽  
Sludge Treatment ◽  
Sewage Sludge Treatment

Phosphorus recovery from waste biomass is becoming increasingly important, given that phosphorus is an exhaustible non-renewable resource. For the recovery of plant nutrients and production of climate-neutral fuel from wet waste streams, hydrothermal carbonization (HTC) has been suggested as a promising technology. In this study, digested sewage sludge (DSS) was used as waste material for phosphorus and nitrogen recovery. HTC was conducted at 200 °C for 4 h, followed by phosphorus stripping (PS) or leaching (PL) at room temperature. The results showed that for PS and PL around 84% and 71% of phosphorus, as well as 53% and 54% of nitrogen, respectively, could be recovered in the liquid phase (process water and/or extract). Heavy metals were mainly transferred to the hydrochar and only <1 ppm of Cd and 21–43 ppm of Zn were found to be in the liquid phase of the acid treatments. According to the economic feasibility calculation, the HTC-treatment per dry ton DSS with an industrial-scale plant would cost around 608 USD. Between 349–406 kg of sulfuric acid are required per dry ton DSS to achieve a high yield in phosphorus recovery, which causes additional costs of 96–118 USD. Compared to current sewage sludge treatment costs in Switzerland, which range between 669 USD and 1173 USD, HTC can be an economically feasible process for DSS treatment and nutrient recovery.

Functional Two-Dimensional Black Phosphorus Nanostructures towards Next-Generation Devices

2021 ◽  
Author(s):  
Mengke Wang ◽  
Jun Zhu ◽  
You Zi ◽  
Zheng-Guang Wu ◽  
Haiguo Hu ◽  
...  
Keyword(s):  
Surface Area ◽  
Biomedical Applications ◽  
Black Phosphorus ◽  
Large Surface Area ◽  
Two Dimensional ◽  
Next Generation

In recent years, two-dimensional (2D) black phosphorus (BP) has been widely applied in many fields, such as (opto)electronics, transistors, catalysis and biomedical applications due to its large surface area, tunable...

Research on metallic chalcogen-functionalized monolayer-puckered V2CX2 (X = S, Se, and Te) as promising Li-ion battery anode materials

2021 ◽  
Author(s):  
Chunmei Tang ◽  
Xiaoxu Wang ◽  
Shengli Zhang
Keyword(s):  
Surface Area ◽  
Anode Materials ◽  
Large Surface Area ◽  
Two Dimensional ◽  
Li Ion Batteries ◽  
Li Ion Battery ◽  
Li Ion ◽  
Battery Anode

Two-dimensional MXene nanomaterials are promising anode materials for Li-ion batteries (LIBs) due to their excellent conductivity, large surface area, and high Li capability.

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