For the commercialization of hydrogen energy, a technology enabling safe storage and the transport of large amounts of hydrogen is needed. Porous materials are attracting attention as hydrogen storage material; however, their gravimetric hydrogen storage capacity (GHSC) at room temperature (RT) is insufficient for actual use. In an effort to overcome this limitation, we present a N-doped microporous carbon that contains large proportion of micropores with diameters below 1 nm and small amounts of N elements imparted by the nitrogen plasma treatment. The N-doped microporous carbon exhibits the highest total GHSC (1.59 wt%) at RT, and we compare the hydrogen storage capacities of our sample with those of metal alloys, showing their advantages and disadvantages as hydrogen storage materials.

Here, we report the preparation of microporous-activated carbons from a Brazilian natural lignocellulosic agricultural waste, cupuassu shell, by pyrolysis at 500 ºC and KOH activation under different experimental conditions and their subsequent application as adsorbent for CO2 capture. The effect of the KOH:precursor ratio (wt/wt%) and the activation temperature on the porous texture of activated carbons have been studied. The values of specific surface area ranged from 1132 to 2486 m2/ g, and the overall micropore volume ranged from 0.73 to 1.02 cm3/ g. Carbons activated with 2:1 ratio of KOH and activation temperature of 700 ºC presented a CO2 adsorption at 1 bar of 7.8 and 4.4 mmol/g at 0 °C and 25 ºC, respectively. The isosteric heat of adsorption, Qst , was calculated for all samples by applying the Clausius–Clapeyron approach to CO2 adsorption isotherms at both temperatures. The values of CO2 adsorption capacities are among the highest reported in the literature, especially for activated carbons produced from biomass.

This research aims to study the effect of impregnation ratio and activation temperature on microporous development of activated carbon (AC). Rubberwood chips, which are wasted from home furnishing industry, were used as precursors for synthesized of activated carbon by chemical activation employing Potassium hydroxide (KOH) as activation agent. Rubberwood char was carbonized at 400 °C for 1 h under inert gas. In this experiment, the rubberwood chars were impregnated with KOH solution by 1:1–3 (char: KOH) impregnation ratio for 24 h, then the samples were activation at 600–800 °C. Surface area, pore volume, micropore volume, pore size distribution, adsorption isotherm and porous structure were analyzed in this experiment to identify the properties of derived activated carbon. According to the investigation, the activated carbon, activated at 800 °C with impregnation ratio of 1:3, demonstrated the highest surface area, pore volume and micropore volume as 1491.75 m2/g, 0.6777 cm3/g, and 0.5813 cm3/g, respectively. Its average pore size was 1.82 nm and it also showed type I adsorption isotherm which indicates as microporous solid.

Poly(imide siloxane)(Si-PI)와 polyvinylpyrrolidone (PVP)를 혼합한 고분자를 사용하여 실리카가 함유된 탄소 분리막을 제조하였다. 고분자 혼합물의 열분해에 의해 제조 된 다공성 탄소 구조의 특성은 두 고분자의 미세 상 분리 거동과 관련이 있다. Si-PI와 PVP의 고분자 혼합물의 유리 전이 온도(Tg)는 시차 주사 열량계를 사용하여 단일 Tg로 관찰되었다. 또 한 C-SiO2 막의 질소 흡착 등온선을 조사하여 다공성 탄소 구조의 특성을 규명했다. Si-PI/PVP로부터 유도 된 C-SiO2 막은 IV형 등온선을 나타내었고 중간기공의 탄소 구조와 관련된 히스테리시스 루프를 가지고 있었다. 분자 여과 확인을 위해서, Si-PI/PVP의 비율과 열분해 온도 및 등온 시간과 같은 열분해 조건을 다르게 하여 C-SiO2 막을 제조하였다. 결과적으로, 120 분 간의 등온 시간 동안 550°C에서 Si-PI/PVP의 열분해에 의해 제조된 C-SiO2 막의 투과도는 820 Barrer (1 × 10-10 cm3 (STP) cm/cm2⋅s⋅cmHg)이었으며, O2/N2 선택도는 14이었다.

The stereotype of flexible MOFs(Amino-MIL-53) and carbonized porous carbon prepared from renewable resources is successfully synthesized for CO2 reduction application. The textural properties of these microporous materials are investigated, and their CO2 storage capacity and separation performance are evaluated. Owing to the combined effects of CO2-Amino interaction and its flexibility, a CO2 uptake of 2.5 mmol g−1 is observed in Amino-MIL-53 at 20 bar 298 K. In contrast, CH4 uptake in Amino-MIL-53 is very low up to 20 bar, implying potential sorbent for CO2/CH4 separation. Carbonized samples contain a small quantity of metal residues(K, Ca, Mg, S), resulting in naturally doped porous carbon. Due to the trace metal, even higher CO2 uptake of 4.7 mmol g−1 is also observed at 20 bar 298 K. Furthermore, the CH4 storage capacity is 2.9 mmol g−1 at 298 K and 20 bar. To evaluate the CO2 separation performance, the selectivity based on ideal adsorption solution theory for CO2/CH4 binary mixtures on the presented porous materials is investigated.

Interconnected meso/microporous activated carbons were prepared from pumpkin seeds using a simple chemical activation method. The porous carbon materials were prepared at different temperatures (PS-600, PS-700, PS-800, and PS-900) and demonstrated huge surface areas (645–2029 m2 g–1) with excellent pore volumes (0.27–1.30 cm3 g–1). The wellcondensed graphitic structure of the prepared activated carbon materials was confirmed by Raman and X-ray diffraction analyses. The presence of heteroatoms (O and N) in the carbon materials was confirmed by X-ray photoemission spectroscopy. High resolution transmission electron microscopic images and selected area diffraction patters further revealed the porous structure and amorphous nature of the prepared electrode materials. The resultant porous carbons (PS-600, PS-700, PS-800, and PS-900) were utilized as electrode material for supercapacitors. To our delight, the PS-900 demonstrated a maximum specific capacitance (Cs) of 303 F g–1 in 1.0 M H2SO4 at a scan rate of 5 mV. The electrochemical impedance spectra confirmed the poor electrical resistance of the electrode materials. Moreover, the stability of the PS-900 was found to be excellent (no significant change in the Cs even after 6000 cycles).

Coloured wastewater is released as a direct result of the production of dyes as well as from various other chemical industries. Many dyes and their breakdown products may be toxic for living organisms. Activated carbon is one of the best materials for removal of dyes from aqueous solutions. The present study describes the adsorption behaviour of methylene blue dye on three microporous activated carbons, where two samples (AC-1 and AC-2) were prepared by a polymer blend technique and the other is a microporous activated carbon (ARY-3) sample from viscose rayon yarn prepared by chemical-physical activation. The effects of contact time and activated carbon dosage on decolourisation capacity have been studied. The results show that activated carbon having mixed microporosity and mesoporosity show tremendous decolourisation capacity for methylene blue. In addition, the activated carbon in the powder form prepared by the polymer blend technique shows better decolourisation capacity for methylene blue than the activated rayon yarn sample.

Microporous carbons with narrow pore size distribution have been successfully synthesized by using hydrolyzed and calcined silica as templates and phenol formaldehyde (pf) resin as carbon precursor. Phenol formaldehyde-silica micro composites were prepared by solution route. Subsesequently, silica templates were removed by HF leaching. Resulting carbons were steam activated. The porous carbons were characterized by nitrogen adsorption-desorption isotherm, SEM, FTIR analysis, iodine adsorption, thermogravimetry analysis, etc. Adsorption isotherms show that the porous carbon prepared from calcined silica as templates are microporous with 88% pores of size <2 nm porosity and are of type I isotherm, while porous carbon prepared by using hydrolyzed silica are microporous with 89% microporosity, shows hysteresis loop at high relative pressure indicating the presence of some mesoporosity in samples. The microporosity in porous carbon materials has a bearing on the nature of silica templates used for pore formation.