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Granular activated carbon (GAC) and powdered activated carbon (PAC) are the two most common forms of activated carbon with varying particle size range. The goal of this study was to analyze the key factors (particle size and activation temperature) affecting the surface characteristics of GAC and PAC derived from palm kernel shell (PKS). The surface morphology suggested that the pore network in PKS-PAC is more developed than that in PKS-GAC owing to the presence of a micropore structure when prepared at lower activation temperatures. This study also demonstrated that activation performed on different PKS particle size range influenced the mesopore domain of the activated carbon produced. The PKS-GAC was found to have more mesopores than PKS-PAC, which made it more reliable for dye adsorption in water treatment. Overall, this study demonstrated that applying different particle size range of PKS during the activation process can have a significant influence on the surface characteristics, thus having a direct impact on the application of activated carbon. An accurate particle size range will ensure that the most cost-effective activated carbon is selected to achieve the desired performance objectives.

In this article it is proved that carbon pastes with ionic liquids (ILs) are a promising material for transducers of reference electrodes, which favors their miniaturization. Two ILs were used: 1‐(2‐hydroxyethyl)‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (IL1) and 1‐(2‐methoxyethyl)‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (IL2). They acted both as a binder of carbon paste and potential‐determining component. ILs were also used in polymeric membrane of reference electrodes what ensured continuity of IL phase between carbon paste and the polymeric membrane and resulted in enhancement of electrode potential stability. It was shown that application of IL as a carbon paste binder is superior to conventional plasticizer and allows for significant increase of reference electrode potential stability. Different types of carbon materials were also tested during research: commercialy available graphite powder and graphene oxide obtained from waste biomass – palm kernel shells. It was observed that both the type of carbon paste material and IL influences reference electrode work parameters. Utilization of IL with less lipophilic cation resulted in higher potential stability of the reference electrodes. Application of graphite paste‐based transducers resulted in higher potential stability of reference electrodes in sodium perchlorate and TMA chloride solutions while using palm kernel shell graphene oxide paste – based transducers caused enhancement of reference electrode long‐term potential stability. The results indicate biomass‐derived graphene oxide can be successfully applied as a construction material of reference electrode. [ABSTRACT FROM AUTHOR]

Activated carbon is the preferred adsorbent for gas and water treatment in various industry across the world due to its efficiency, reliability, and accessibility. Recently, in Malaysia, studies are mainly focused on the fabrication of activated carbon from lignocellulosic biomass-based precursors from agricultural waste such as coconut shell, rice husk, and palm kernel shell. Activated carbon fabrication is a two-step process; the precursor will first undergo carbonization, then, activation is carried out either physically or chemically to develop its porous surface for adsorption purposes. The main benefit of activated carbon is the customizable pore structure for different utilization, which can be easily achieved by the chemical activation process. The types and concentration of chemicals used for activation, pre-treatment of precursor, duration of the activation process, and the mass ratio of precursor to chemicals are proven to effectively influence the resulting pore structure. However, the chemicals used in the activation process can be harmful to the environment. Thus, the chemical recovery process is necessary after the activation process. Nonetheless, more in-depth research on producing activated carbon from abundant biomass materials with bio-based chemical agents for activation is needed to achieve an ecological and sustainable manufacturing process.