Hierarchically porous carbons (HPCs) with 1D to 3D network are attracting vast interest due to their potential technological application profile ranging from electrochemical capacitors, lithium ion batteries, solar cells, hydrogen storage systems, photonic material, fuel cells, sorbent for toxic gas separation and so on. Natural raw-materials such as biomass-biopolymer derived hierarchical nanostructured carbons are especially attractive for their uniform pore dimensions which can be adjustable over a wide range of length scales. Good electrical conductivity, high surface area, and excellent chemical stability are unique physicochemical properties which are responsible for micro/nanostructured porous carbon to be highly trusted candidate for emerging nanotechnologies. This review focuses on the ‘out-of-the-box’ synthetic techniques capable of deriving HPC with superior application profiles. The article presents the promising scope of accessing HPCs from (1) hard-templating, soft-templating, and non-templating routes, (2) biopolymers with a major focus on non-templating strategies. Subsequently, emerging strategies of hetero-atom doping in porous carbon nanostructures are discussed. The review will highlight the contribution of synergistic effect of macro–meso–micropores on a range of emerging applications such as CO2 capture, carbon photonic crystal sensors, Li–S batteries, and supercapacitor. Mechanism of ion transport and buffering, electrical double layer enhancement have been discussed in the context of pore structure and shapes. We will also show the differences of HPC and ordered mesoporous carbon (OMC) in terms of their synthesis strategies and choices of template for self-assembly. How the remarkable mechanical strength of the HPCs can be achieved by selecting self-assembling template, whereas collapse of mesostructure via decomposition of framework occurs due to poor thermal stability or high N-content of the carbon source will be discussed.

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Hierarchically porous carbon derived from polymers and biomass: effect of interconnected pores on energy applications

Adsorption of VOCs onto engineered carbon materials: A review

A review on surface modification of activated carbon for carbon dioxide adsorption

An overview of the modification methods of activated carbon for its water treatment applications

Chelating groups are successfully linked to graphene oxide (GO) surfaces through a silanization reaction between N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (EDTA-silane) and hydroxyl groups on GO surface. EDTA-GO was found to be an ideal adsorbent for Pb(II) removal with a higher adsorption capacity. EDTA-modification enhances the adsorption capacity of GO because of the chelating ability of ethylene diamine triacetic acid. This study investigates the adsorption and desorption behaviors of heavy metal cations and the effects of solution conditions such as pH on Pb(II) removal. The adsorption capacity for Pb(II) removal was found to be 479 ± 46) mg/g at pH 6.8, and the adsorption process was completed within 20 min. The Langmuir adsorption model agrees well with the experimental data. The experimental results suggest that EDTA-GO can be reused after washed with HCl, suggesting potential applications in the environmental cleanup.

Adsorption Behavior of EDTA-Graphene Oxide for Pb (II) Removal

Surface Chemical Functional Groups Modification of Porous Carbon

Photocatalytic degradation for methylene blue using zinc oxide prepared by codeposition and sol–gel methods

The dynamic transesterification reaction of peanut oil in supercritical methanol media was investigated. The reaction temperature and pressure were in the range of 250°C–310°C and 10.0 MPa–16.0 Mpa, respectively. The molar ratio of peanut oil to methanol was 1:30. It was found that the yield of methyl esters was higher than 90% under the supercritical methanol. The apparent reaction order and activation energy of transesterification was 1.5 and 7.472 kJ/mol, respectively. In this method, the reaction time was shorter and the processing was simpler than that of the common acid catalysis transesterification.

Reaction Kinetics of Transesterification between Vegetable Oil and Methanol under Supercritical Conditions

The effect of carbon precursor on the pore size distribution of mesoporous carbon during templating synthesis process

Activated carbons are widely used in separation and purification processing, and as catalysis supports [1, 2]. Activated carbon fibers (ACFs) as a new type of activated carbon have an excellent adsorptive property due to large specific surface area, pore volume, and uniform microporosity. Generally, the micropore in ACF cannot meet some special demands, such as adsorption of bulky molecules from solution and catalyst supports for macromolecule reaction [3]. So, it is desired to increase the mesopore and macropore content in ACF and exploit its new applications. Polymer additives or catalyst was added to the carbon source and carbonized to obtain mesoporous carbon fiber; but it was difficult to eliminate the catalyst from the mesoporous carbon fiber matrix [4–6]. The transition metal and rare earth metal compounds can promote the development of mesopores in activated carbon [7–9]. The activation reaction takes place in the immediate vicinity of metal/oxide particles, leading to the formation of mesopores and macrospores by pitting holes into the carbon matrix [10]. Potassium hydrate can promote the mesopore development, but it needs higher loading amount if the post-treatment is complex. Yttrium acetylacetonate [Y(acac)3] was added to the precursor of carbon and used as catalyst to increase the mesopore content of ACF, but the cost was high [11]. Cerium oxide showed certain activity due to its role in the oxidization–reduction cycle [12] and it could promote the mesopore development in activated carbon with scatter pore size distribution due to the original property of activated carbon [13]. In the current work, cerium nitrate was selected to investigate its catalytic effect on the mesopore development of commercial ACF with steam activation. The commercial ACF was first impregnated with the aqueous solution of cerium nitrate. The loadings of cerium nitrate on the basis of activated carbon were 2.0 wt%. The samples were then dried at 110 ◦C for

Preparation of mesoporous activated carbon fiber by steam activation in the presence of cerium oxide and its adsorption of Congo red and Vitamin B12 from solution

Yihong Liu

Papers

Surface Chemical Functional Groups Modification of Porous Carbon

Photocatalytic degradation for methylene blue using zinc oxide prepared by codeposition and sol–gel methods

Reaction Kinetics of Transesterification between Vegetable Oil and Methanol under Supercritical Conditions

The effect of carbon precursor on the pore size distribution of mesoporous carbon during templating synthesis process

Preparation of mesoporous activated carbon fiber by steam activation in the presence of cerium oxide and its adsorption of Congo red and Vitamin B12 from solution