Annual Review: CIQTEK BET Series Contributes to Multiple Research Publications

Results Brief

Appl. Catal. B：Porous graphitized carbon-supported FeOCl as a bifunctional adsorbent-catalyst for the wet peroxide oxidation of chlorinated volatile organic compounds: Effect of mesopores and mechanistic study

Wet scrubbing combined with adsorption-enhanced heterogeneous advanced oxidation processes (AOPs) is an effective method to treat chlorinated volatile organic compounds (CVOCs). A porous graphitized carbon (PGC)-loaded FeOCl catalyst was developed by the group of Mr. Jinjun Li from Wuhan University for the effective removal of gaseous dichloroethane, trichloroethylene, dichloromethane, and chlorobenzene. The PGC-loaded FeOCl catalyst was characterized by BET and analyzed for adsorption performance, and it was found that the PGC-loaded FeOCl catalyst had a well-developed mesoporous structure, which could accelerate the diffusion of organic molecules within the particles, and showed better removal performance for CVOCs.

CIQTEK EASY-V series products used in the study

Chem. Eng. J：Micro-mesoporous graphitized carbon fiber as hydrophobic adsorbent that removes volatile organic compounds from air

Activated carbon fibers (ACFs) are a popular class of adsorbents for volatile organic compounds (VOCs). Mr. Jinjun Li's group at Wuhan University prepared hydrophobicity-enhanced porous graphitized carbon fibers (PGCFs) by KOH-catalyzed graphitization and studied their adsorption capacity of representative VOCs, which was characterized to show that PGCFs have a high specific surface area of more than 2,200 m²/g and a micromediaturized pore structure, and that selective adsorption capacity of organics was improved under humid conditions.

CIQTEK EASY-V series products used in the study

Chem. Eng. J：Bamboo-derived hydrophobic porous graphitized carbon for adsorption of volatile organic compounds

Hydrophobic bamboo-based porous graphitized carbons (BPGCs) were prepared by a composite catalytic graphitization method to study their adsorption performance on toluene, cyclohexane and ethanol, and the specific surface area sizes and micromesopore ratios of the carbon materials prepared at different synthesis temperatures were tested by BET characterization, which provides some theoretical support for evaluating the adsorption performance of carbon materials.

CIQTEK EASY-V series products used in the study

Material Adsorption Property Testing Technology

Photocatalytic-driven CO₂ reduction coupled with photo-oxidative conversion of plastic wastes into value-added chemicals is an effective strategy to address the greenhouse and environmental crises. The porous graphitized carbons (PGCs) and PGC-loaded FeOCl catalysts (FeOCl/PGCs) synthesized at different ratios were characterized by a specific surface and pore size analyzer, and the N₂ adsorption and desorption isotherms are shown below in Fig.1d. The adsorption of N₂ by PGC0 and FeOCl/PGC0 was mainly in the low relative pressure band at P/P₀< 0.1, which is a typical microporous material characteristics.

In contrast, the N₂ adsorption of the other PGCs and FeOCl/PGCs increased consistently with relative pressure, and the hysteresis loops were present in all isotherms, suggesting the presence of mesoporous structures in the materials. The isothermal characteristics of the FeOCl/PGC catalysts were very similar to those of their corresponding PGC carriers, with the difference of a slight decrease in the amount of nitrogen adsorbed only, which suggests that catalyst loading did not significantly alter the carbon materials' porosity of the carbon material. From the NLDFT pore size distribution in Fig. 1e below and the detailed data in Table 1, it can be seen that the percentage of mesopores of the materials increased after graphitization, and the specific surface area of the carbon materials gradually decreased with the increase of graphitization. The DCE removal efficiencies of PGC0, PGC1, PGC3, PGC4, and PGC8 were 26.5%, 25.0%, 22.2%, 19.7%, and 16.5%, respectively. The order of DCE removal efficiency was consistent with the order of specific surface area of PGCs, which was attributed to the fact that with the gradual occupation of adsorption sites during wet washing of DCE by adsorption method, the more adsorption sites were available for materials with larger specific surface area, the better the removal effect.

Fig. 1. (d) Nitrogen adsorption–desorption isotherms and (e) pore size distribution curves of different material

The following figure shows the N₂ adsorption and desorption isotherms and NLDFT pore size distribution data obtained from the characterization of different carbon materials. Viscose-based activated carbon fibers (VACFs) showed an I-type isotherm, whose nitrogen adsorption increased dramatically in the low relative pressure section of P/P₀ < 0.05, and the isotherm tended to flatten out at higher P/P₀, which indicated that the material was dominated by micropores. In contrast, the isotherms of porous graphitized carbon fibers (PGCFs) showed a gradual increase in adsorption with increasing P/P₀, in addition to significant nitrogen adsorption in the low P/P₀ section, indicating the presence of both micropores and mesopores in PGCFs. From the NLDFT data, it can be seen that most of the pore widths of VACF are less than 2 nm, whereas PGCF has a distribution in the microporous range and a concentrated distribution in the mesoporous range larger than 2 nm. In addition, by comparing the detailed data of specific surface area and pore volume of the materials, it can be found that the specific surface area increases from 1304 m2/g to more than 2200 m2/g after converting VACF to PGCF, and the pore volume, especially the mesopore volume, increases dramatically, and the mesopore volume accounts for more than half of its total pore volume. The higher specific surface area of the PGCFs than that of the VACFs further explains that the PGCFs are more sensitive to toluene and cyclohexane. The higher specific surface area of PGCFs than VACFs further explains the enhanced adsorption of toluene and cyclohexane by PGCFs.

Specific surface and pore size characterization of biomass-based activated carbons (BACs) and bamboo-based porous graphitized carbons (BPGCs) prepared by different methods showed that the adsorption of N₂ by BACs mainly occurred at low relative pressures (P/P₀<0.05), which showed a typical I-type isotherm, indicating that BACs were predominantly microporous. In contrast, in addition to adsorption at P/P₀<0.05, nitrogen adsorption by BPGCs still increased with the increase of P/P₀, and there was a hysteresis loop, indicating the presence of both micropores and mesopores in BPGCs. As shown in Table 1 below, by comparing the detailed data of specific surface area and pore size distribution of different carbon materials, it can be seen that the mesopore volume of BAC only accounts for 20% of its total pore volume, while the mesopore volume of BPGCs generally accounts for more than 44%, of which BPGC-500 has the largest surface area (2181 m2/g) and the highest mesopore volume, and the larger mesopore volume of BPGC ensures that the condensate will have enough porous volume after the absorption of The large mesopore volume of BPGC ensures that there is enough space for the condensate to expand after the absorption of ethanol.

CIQTEK BET Surface Area & Porosimetry Analyzer

EASY-V 3220 & 3210 are the BET specific surface area and pore size analysis instruments developed independently by CIQTEK, using the static volumetric method.

▪  Specific surface area testing, range 0.0005 (m²/g) and above.

▪  Pore size analysis: 0.35 nm-2 nm (micropore), micropore size distribution analysis; 2 nm-500 nm (mesopore or macropore).

▪  Two analysis stations. EASY-V 3220: simultaneous testing of 2 samples; EASY-V 3210: alternate testing of 2 samples.

▪  Equipped with the molecular pump.

Articles published using CIQTEK products

1.Porous graphitized carbon-supported FeOCl as a bifunctional adsorbent-catalyst for the wet peroxide oxidation of chlorinated volatile organic compounds: Effect of mesopores and mechanistic study. Applied Catalysis B: Environmental（2023）

2.Micro-mesoporous graphitized carbon fiber as hydrophobic adsorbent that removes volatile organic compounds from air. Chemical Engineering Journal（2023）

3.Bamboo-derived hydrophobic porous graphitized carbon for adsorption of volatile organic compounds. Chemical Engineering Journal（2023）

4.Chiral Nanosilica Drug Delivery Systems Stereoselectively Interacted with the Intestinal Mucosa to Improve the Oral Adsorption of Insoluble Drugs. ACS Nano（2023）

5.A facile“thick to thin”strategy for integrating high volumetric energy density and excellent flexibility into MXene/wood free-standing electrode for supercapacitors. Chemical Engineering Journal（2023）

6.The efficiency and mechanism of excess sludge-based biochar catalyst in catalytic ozonation of landfill leachate. Journal of Hazardous Materials（2023）

7.Aqueous Zn-ion batteries using amorphous Zn-buserite with high activity and stability. Journal of Materials Chemistry A（2023）

8.Rapid complete reconfiguration induced actual active species for industrial hydrogen evolution reaction. Nature Communications（2022）

9.Catalytic aromatic ring hydrogenation over ruthenium nanoparticles supported on α-Al₂O₃ at room temperature. Applied Catalysis B: Environmental（2022）

10.Engineered neutrophil apoptotic bodies ameliorate myocardial infarction by promoting macrophage efferocytosis and inflammation resolution. Bioactive Materials（2022）

11.Role and significance of co-additive of biochar and nano-magnetite on methane production from waste activated sludge: Non-synergistic rather than synergistic effects. Chemical Engineering Journal（2022）

12.Micro-mesoporous graphitized carbon fiber as hydrophobic adsorbent that removes volatile organic compounds from air. Chemical Engineering Journal（2022）

13.Mercerization of tubular bacterial nanocellulose for control of the size and performance of small-caliber vascular grafts. Chemical Engineering Journal（2022）

14.Experimental and theoretical research on pore-modified and K-doped Al2O3 catalysts for COS hydrolysis: The role of oxygen vacancies and basicity. Chemical Engineering Journal（2022）

15.Novel Zn-Fe engineered kiwi branch biochar for the removal of Pb(II) from aqueous solution. Journal of Hazardous Materials（2022）

16.Efficient with low-cost removal and adsorption mechanisms of norfloxacin, ciprofloxacin and ofloxacin on modified thermal kaolin: experimental and theoretical studies. Journal of Hazardous Materials（2022）

17.α-MoB₂ Nanosheets for Hydrogen Evolution in Alkaline and Acidic Media. ACS Applied Nano Materials（2022）

18.COD inhibition alleviation and anammox granular sludge stability improvement by biochar addition. Journal of Cleaner Production（2022）

19.In situ construction of FeNi2Se4-FeNi LDH heterointerfaces with electron redistribution for enhanced overall water splitting. Royal Society of Chemistry（2022）

20.Role and significance of water and acid washing on biochar for regulating methane production from waste activated sludge. Science of The Total Environment（2022）

21.Soil properties affect vapor-phase adsorption to regulate dimethyl disulfide diffusion in soil. Science of The Total Environment（2022）

22.Removal of lead (Pb⁺²) from contaminated water using a novel MoO3-biochar composite: Performance and mechanism. Environmental Pollution（2022）

23.Acid washed lignite char supported bimetallic Ni-Co catalyst for low temperature catalytic reforming of corncob derived volatiles. Energy Conversion and Management（2022）