The Analysis of Pore Development and Formation of Surface Functional Groups in Bamboo-Based Activated Carbon during CO2 Activation

Abstract

Pore development and the formation of oxygen functional groups were studied for activated carbon prepared from bamboo (Bambusa bambos) using a two-step activation with CO2, as functions of carbonization temperature and activation conditions (time and temperature). Results show that activated carbon produced from bamboo contains mostly micropores in the pore size range of 0.65 to 1.4 nm. All porous properties of activated carbons increased with the increase in the activation temperature over the range from 850 to 950 °C, but decreased in the temperature range of 950 to 1000 °C, due principally to the merging of neighboring pores. The increase in the activation time also increased the porous properties linearly from 60 to 90 min, which then dropped from 90 to 120 min. It was found that the carbonization temperature played an important role in determining the number and distribution of active sites for CO2 gasification during the activation process. Empirical equations were proposed to conveniently predict all important porous properties of the prepared activated carbons in terms of carbonization temperature and activation conditions. Oxygen functional groups formed during the carbonization and activation steps of activated carbon synthesis and their contents were dependent on the preparation conditions employed. Using Boehm’s titration technique, only phenolic and carboxylic groups were detected for the acid functional groups in both the chars and activated carbons in varying amounts. Empirical correlations were also developed to estimate the total contents of the acid and basic groups in activated carbons in terms of the carbonization temperature, activation time and temperature.

Noble-metal-free single-phase Co3V2O8with the structural integrity of nanofibers for the selective detection of ascorbic acid

“…The surface area and pore size distribution of an electrocatalyst are important factors that influence the adsorption kinetics employed to measure the diffusion of the adsorbate into the pores. 36,37 surface area of 14.882 m 2 g −1 with a superior total pore volume of 0.1323 cm 3 g −1 as compared with previously reported Co 3 V 2 O 8 nanoparticles. 29 Due to the characteristic feature of mesopores, the prepared Co 3 V 2 O 8 has evenly distributed pore structures on its surface.…”

“…The surface area and pore size distribution of an electrocatalyst are important factors that influence the adsorption kinetics employed to measure the diffusion of the adsorbate into the pores. 36,37 Fig. 5 illustrates the specific Brunauer–Emmett–Teller (BET) surface area and total pore volume of the Co 3 V 2 O 8 nanofibers, affording a specific surface area of 14.882 m 2 g −1 with a superior total pore volume of 0.1323 cm 3 g −1 as compared with previously reported Co 3 V 2 O 8 nanoparticles.…”

Advances in Micro-/Mesopore Regulation Methods for Plant-Derived Carbon Materials

“…Ding et al [ 87 ] investigated the effect of different preparation processes on the properties of the materials and found that the material subjected to multi-step activation displayed higher specific surface area (1690 m 2 /g) and pore volume (0.93 cm 3 /g), while one-step activation yielded a relatively high microporosity (72.0%), which is about 1700, 162, and 72 times larger than that of the unactivated materials, respectively. Phothong [ 89 ] and Khuong [ 90 ] investigated the effect of CO 2 activation temperature and activation time on the pore structure of bamboo-derived carbon materials, respectively. The results showed ( Figure 8 b–d) that the carbon material had the maximum microporosity when the activation temperature was 850 °C.…”

“… ( a ) Schematic diagram of preparing wood-derived carbon materials by self-activation [ 95 ]; ( b – d ) Impact of temperature on physical activation effect [ 89 ]; ( e – g ) Impact of char/alkali mass ratio on NaHCO 3 activation effect [ 90 ]. …”

The Use of High Surface Area Mesoporous-Activated Carbon from Longan Seed Biomass for Increasing Capacity and Kinetics of Methylene Blue Adsorption from Aqueous Solution

“…The mesopore volume was estimated by subtracting the micropore volume from the total pore volume. The pore size distributions of the derived activated carbons were determined from the N 2 adsorption isotherms data by applying the Grand Canonical Monte Carlo (GCMC) simulation [25,28,29]. The average pore size (D av ) was computed based on the equation 4V T /S, where V T is the total pore volume and S is the BET surface area, assuming the pores are cylinder.…”