MOLECULES
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2023
·Vol. 28
·期 14
·5310
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IF 4.6
Yanjun Zhao,Xintong Liu,Wenhui Li,Suyun Pei,Yifan Ren,Xinyang Li,Chen Qu,Chuandong Wu,Jiemin Liu
In this study, pristine kiwi peel (KP) and nitric acid modified kiwi peel (NA-KP) based adsorbents were prepared and evaluated for selective removal of cationic dye. The morphology and chemical structure of KP and NA-KP were fully characterized and compared, and results showed nitric acid modification introduced more functional groups. Moreover, the adsorption kinetics and isotherms of malachite green (MG) by KP and NA-KP were investigated and discussed. The results showed that the adsorption process of MG onto KP followed a pseudo-second-order kinetic model and the Langmuir isotherm model, while the adsorption process of MG onto NA-KP followed a pseudo-first-order kinetic model and the Freundlich isotherm model. Notably, the Langmuir maximum adsorption capacity of NA-KP was 580.61 mg g−1, which was superior to that of KP (297.15 mg g−1). Furthermore, thermodynamic studies demonstrated the feasible, spontaneous, and endothermic nature of the adsorption process of MG by NA-KP. Importantly, NA-KP showed superior selectivity to KP towards cationic dye MG against anionic dye methyl orange (MO). When the molar ratio of MG/MO was 1:1, the separation factor (αMG/MO) of NA-KP was 698.10, which was 5.93 times of KP. In addition, hydrogen bonding, π-π interactions, and electrostatic interaction played important roles during the MG adsorption process by NA-KP. This work provided a low-cost, eco-friendly, and efficient option for the selective removal of cationic dye from dyeing wastewater.Keywords:kiwi peel;acid-modified adsorbent;selective adsorption;malachite green;nitric acid modification
研究领域:
环境科学
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化学工程
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材料科学
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DOI
PubMed
高影响因子
Catalysts
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2022
·Vol. 12
·期 11
·1299
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IF 4.501
Yidi Zhou,Xin Min,Lijuan Wang,Yajing Zhao,Bozhi Yang,Xiaoxian Wu,Dan Zhang,Xifeng Hou,Yan’gai Liu,Minghao Fang,Zhaohui Huang
The critical need to enhance the quality of indoor air leads to the improvement of catalyst activity for the removal of formaldehyde. Sepiolite can be utilized in catalytic reactions for its unique structure, composition and high surface area. The adhesion between sepiolite fibers and the blocked microporous channel (by impurities) demands the activation of natural sepiolite through acid treatment. This treatment successfully produces acid-modified sepiolite Pt-supported samples. The impacts of different acid concentrations, Pt loading content and calcination temperature on catalytic activity for formaldehyde (HCHO) oxidation are studied. The catalytic activity of HCHO is characterized and evaluated by techniques including specific surface area, X-ray diffraction, Fourier transform infrared spectrum, X-ray photoelectron spectroscopy and transmission electron microscopy. The results show the maximum specific area of sepiolite at the optimized 0.06 M acid concentration. Among all the prepared samples, the 0.02Pt/Sep catalyst calcined at 500 °C exhibits the highest catalytic activity for the oxidation of HCHO.Keywords:HCHO;sepiolite;acid-modified;Pt nanoparticles
研究领域:
环境科学
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催化化学
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DOI
高影响因子
Journal of Central South University
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2021
·Vol. 28
·期 6
·1652-1664
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IF 1.716
Jiang Chun-lu,Wang Rui,Chen Xing,Zheng Liu-gen,Cheng Hua
Chitosan-coated fly ash (CWF) was prepared by the acid leaching-coating method. Chitosan and fly ash were crosslinked in the solution of acetic acid and sulfuric acid. The microstructure of CWF was conducted by scanning electron microscope (SEM) and X-ray diffraction (XRD). The removal of Cr(VI) from water by CWF was studied by adsorption experiments. The composite prepared by the experiment developed a pore structure and a crystal structure similar to SiO 2 and chitosan chain-like coating was formed on the surface of fly ash. The new modified material has larger surface roughness, specific surface area and more adsorption channels. The Cr(VI) was enriched in modified materials by electrostatic adsorption between CrO 4 2− , CrO 7 2− and —NH 3 + group and surface acid functional groups. The movement of Cr(VI) in solution is a diffusion process from the main body of the liquid phase to the surface of the liquid film.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Li Li,Guanzheng Zhuang,Peng Yuan
Sepiolite can form stable hybrid pigments by immobilizing organic dyes in its microporous structure. Previous investigations demonstrated that the micropores and coordinated water might be responsible for the exceptional color and stability of indigo-sepiolite hybrid pigments. This work reveals the roles of coordinated water in forming hybrid pigments by acid modification. Raw sepiolite was modified by nitric acid at different conditions before use. Then a series of indigo-sepiolite pigments were prepared by indigo and acid-modified sepiolite. Their microstructures were characterized and analyzed by X-ray diffraction, Fourier transform infrared, transmission electron microscopy , and N 2 adsorption-desorption. The color properties of hybrid pigments were evaluated by reflectance spectra and CIE color parameters. Investigations into the chemical stability of pigments were conducted using concentrated HNO 3 and dimethyl sulfoxide. In addition, the photostability of pigments exposed to simulated 30-year illumination in a typical museum was studied. Acid modification of sepiolite contributed to a larger specific surface area and pore volume. However, acid modification resulted in worse color properties and stability due to the removal of coordinated water bonded with octahedral Mg 2+ . These findings confirmed that coordinated water molecules were the key to stabilizing indigo-sepiolite hybrid pigments by forming hydrogen bonds .
研究领域:
材料科学
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化学
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DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
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IF 5.4
Kang Jing,Sen Chen,Qianru Shi,Luping Lu,Hui Liu
Ag@Ti 3 C 2 -TA nanocomposite catalyst was elaborately constructed by a simple and green method with Ti 3 C 2 as the carrier, tannic acid (TA) as the modifier, and silver nitrate as the precious metal precursor. A series of characterizations were used to analyze morphology and microstructure of the resulting catalyst. The degradation behaviors of the catalyst were studied with rhodamine B (RB) and methyl orange (MO) as the model dyes. The result demonstrated that Ag@Ti 3 C 2 -TA exhibited efficient catalytic degradation performance toward both RB and MO, and the degradation percentage increased with the growth of TA content in the catalyst. The catalytic degradation process conformed to the quasi-level kinetic model, and catalytic reaction rate constants of Ag@Ti 3 C 2 -TA for RB and MO were 0.972 and 1.478 min −1 , respectively. The catalytic degradation percentage of Ag@Ti 3 C 2 -TA toward RB and MO still remained above 80% even after 10 catalytic cycles, indicating high degradation percentage and considerable catalytic stability.
研究领域:
材料科学
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环境科学
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催化化学
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产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
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2020
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IF 5.715
Xiangping Li,Chuanbin Wang,Jingnan Tian,Juping Liu,Guanyi Chen
Using biochar to remove heavy metals from water is environmentally beneficial. In this study, three kinds of chemical reagents, including ZnCl 2 , H 3 PO 4 and KMnO 4 , were introduced to modify the biochar derived from Enteromorpha prolifera . The performance of these modified biochar in removing Cadmium ions (Cd(II)) from water was investigated. The physicochemical properties of activated biochars were characterized by N 2 -sorption, thermal gravity and differential thermal gravity (TG/DTG), scanning electron microscopy (SEM), elemental analysis and Fourier transform infrared spectroscopy (FTIR). The results showed that the removal rate of Cd(II) from water by EP biochar modified with H 3 PO 4 was significantly increased, and the maximum adsorption capacity of Cd(II) reached to 423 mg/g for PBC. Moreover, the adsorption of Cd(II) from water by phosphoric acid modified biochar was very fast, and the saturation adsorption of Cd(II) was reached within 1 h. Compared with pseudo first-order model, pseudo secondary-order model was much more suitable for analyzing the adsorption kinetics data of Cd(II) onto KBC or ZBC. The adsorption of Cd(II) onto PBC was analyzed by the intra-particle diffusion kinetic model, where the value of R 2 was high as 0.98. The Langmuir model was fit for phosphoric acid modified biochar.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
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2022
·
IF 3.475
Maoyou Ye,Yi Fang,Hongjing Xiang,Hui Liu,Huimin Yan,Bingmin Wang,Xinle Lin,Jialin Liang,Wei Qian
Currently, ofloxacin (OFX) is widely used in various medical treatment and aquaculture industries. However, its production and application produces waste which pollutes the natural environment and causes ecological damage. The application of biochar is a crucial way to remove OFX antibiotics from wastewater. In this paper, bagasse was used as the material to be pyrolyzed to obtain bagasse biochar (BC). BC was modified with HNO3 and KOH to prepare acid-modified sugarcane biochar (HBC) and alkali-modified sugarcane biochar and subsequently applied to the treatment of ofloxacin wastewater. The results showed that the adsorption capacity of HBC was 2.2 times higher than that of BC, and it had better adsorption performance. When the dosage of acid-modified biochar was 1 g/L and the initial pH of the solution was 7.0, the OFX removal rate reached 88.5% after 90 min of reaction. HBC has good stability, and the OFX removal efficiency is still up to 78.5% after 5 cycles. According to the adsorption simulation results, the adsorption of the three biochar materials is more consistent with the Freundlich adsorption model, and the simulated linear correlation coefficient is higher than 0.99. The Kfr value of HBC is 6.6042, which exhibits the highest adsorption capacity. Moreover, the three biochars exhibit better simulation results in pseudo-second-order kinetics fitting, and the linear correlation coefficients are above 0.99. The adsorption mechanism of bagasse biochar for ofloxacin in wastewater was π-π electron donor–acceptor interactions. The results show that bagasse biochar has good feasibility in the treatment of ofloxacin wastewater.
研究领域:
环境科学
·
废水处理
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DOI
PubMed
高影响因子
TOPICS IN CATALYSIS
·
2024
·
IF 2.8
Wang Xinyu,Xu Xin,Xiong Wuwan,Ye Daiqi,Chen Peirong
Catalytic oxidation is an effective solution for the control of methane (CH 4 ) emission in exhausts from natural gas vehicles. Pd-based small-pore zeolites (such as Pd-SSZ-13) are considered to be the most active catalysts for CH 4 oxidation, but H 2 O in the exhausts tends to induce deactivation of Pd catalysts. In this work, we tuned the hydrophobicity of Pd-SSZ-13 as a representative to improve its H 2 O resistance in CH 4 oxidation. Pd-SSZ-13 catalysts with different Si/Al ratios were obtained by dealuminizing the pristine SSZ-13 zeolite with acid followed by Pd ion exchange, and a reduction of T 50 (i.e. the temperature to reach 50% conversion of CH 4 ) by 20 ℃ was achieved in CH 4 oxidation in the presence of 10 vol.% H 2 O. Detailed physicochemical characterizations showed that the fraction of highly dispersed PdO species (highly active in CH 4 oxidation) increased, whereas that of less inactive PdO x clusters decreased, in the Pd-SSZ-13 after acid modification. In addition, the increase of zeolite hydrophobicity after acid modification alleviated the H 2 O inhibition effect on the active PdO phase, leading to a less activity loss of Pd-SSZ-13 in CH 4 oxidation. The improved hydrophobicity also favored C 3 H 8 combustion over Pd-SSZ-13. These results suggested that simple acid modification could tune effectively the Si/Al ratio and hydrophobicity of zeolite supports, and eventually the physicochemical properties and oxidation performance of the supported Pd catalysts.
研究领域:
催化化学
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环境科学
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DOI
高影响因子
FUEL
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2022
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IF 8.035
Yujie Hou,Zongqing Bai,Hao Lu,Zhihao Feng,Tingting Zhang,Yuxing Jia,Zhenxing Guo,Lingxue Kong,Jin Bai,Wen Li
Low-cost kaolin was modified by calcination at different temperatures, followed by HCl leaching, and used as catalyst for in-situ upgrading of Hami coal pyrolysis volatiles in a fixed-bed reactor. The catalyst characteristics, pyrolysis product distributions and tar properties were investigated by multiple methods to understand the relationship between catalyst properties and tar quality. The results indicated that calcination of kaolin promoted the formation of amorphous metakaolin, then the HCl leaching removed most metakaolin framework Al, leading to the production of abundant micro-/mesopores and acid sites. As the rising calcination temperature, the specific surface area and pore volume of acid-modified kaolin (AMK) showed a trend of increasing and then decreasing, and the Brønsted acid sites (BAS) displayed an increasing trend. Compared to non-catalytic pyrolysis, the high specific surface area and certain acid sites of AMKs enhanced the light tar fraction from 37.81 wt% to 43.00–48.45 wt%, and the relative content of aromatics in tar increased from 9.76% to 16.65–22.11%, with monocyclic aromatics, naphthalenes and polycyclic aromatics increasing to 3.5–4.2, 1.2–1.8 and 2.1–3.3 times higher, respectively. AMKs also reduced the content of element O in tar by 17.92–31.54% by promoting the deoxygenation reaction. The tar upgrading performance was determined by the BAS amount and the pore structure of AMKs together. Among all AMKs, AMK800 (calcined at 800 °C and treated by HCl) exhibited the optimum performance for heavy tar conversion, aromatics generation and oxygen removal due to its highest specific surface area and the maximum BAS except AMK900. The acid-modified kaolin has the potential to be an inexpensive and efficient catalyst for future practical applications of upgrading coal pyrolysis tar.
研究领域:
化学工程
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能源科学
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DOI
高影响因子
KINETICS AND CATALYSIS
·
2024
·Vol. 65
·期 3
·298-307
·
IF 1.3
Liu Wei,Wu Fengqin,Liu Jingwei,Meng Jie,Gao Bingying,Zuo Shixiang,Yao Chao
The specific surface area of attapulgite was significantly enhanced (from 128 to 212 m 2 /g) by its purification with sodium hexametaphosphate and nitric acid. Subsequently, an acid modification method was employed to prepare a coated attapulgite cordierite honeycomb with a specific surface area approximately 39 times larger than that of the bare cordierite honeycomb. SEM images showed that the surface of the cordierite was rough and uneven, with the attapulgite filling the large pores on its surface, forming a “nail-like” interaction between the coating and the carrier. After loading the catalyst, no significant mass loss was observed after 1 h of ultrasonic testing, indicating good adhesion stability of the coating. Furthermore, under test conditions of GHSV (Gas Hourly Space Velocity) = 10 000 h –1 and a toluene concentration of 1500 ppm, the prepared integrated catalyst exhibited excellent activity for the catalytic oxidation of toluene, with T 50 and T 90 values of 261 and 290°C, respectively, suggesting broad application prospects.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 51
·77536-77552
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IF 5.19
Xue Yun,Cheng Wanting,Cao Meng,Gao Jianzhang,Chen Jiaqi,Gui Yunyang,Zhu Wenmin,Ma Fuqiu
In this paper, nitric acid-modified activated carbon was used as an electrode in the electrosorption process for the removal of Co 2+ , Mn 2+ , and Ni 2+ from wastewater. The effects of applied voltage, initial pH, and coexisting ions on removal efficiency were investigated. The adsorption process was evaluated by adsorption isotherm models. The results indicated that the electrosorption process was consistent with the Langmuir model, proving that the electrosorption process was a monolayer adsorption process. The maximum adsorption capacities of Co 2+ , Mn 2+ , and Ni 2+ were 131.58 mg/g, 102.04 mg/g, and 103.09 mg/g. Electrochemical tests revealed that the specific capacitance of AC-HNO 3 was 54.11 F/g when the scanning rate was 5 mV/s, while the specific capacitance of AC was 36.51 F/g. The Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) confirmed that the content of oxygen groups on the surface of activated carbon increased after modification, which provided more adsorption sites for electrosorption. When the selected concentration of HCl was used as the eluent, the elution efficiency of Co 2+ , Mn 2+ , and Ni 2+ could reach 94.23%, 93.65%, and 90.61%. The removal efficiency could reach more than 95% after three cycles. The results of the study can be used as a reference significance for the removal of cobalt, manganese, and nickel ions from heavy metal wastewater by electrosorption.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
POLYMER TESTING
·
2025
·
IF 6
Ruizhi Zheng,Renjie Chen,Feng Wu,Delong Xie,Yi Mei
This study developed form-stable phase change materials (FSPCMs) with high energy storage density, superior flame retardancy, and effective smoke suppression by incorporating boric acid-grafted octadecanol (BO) as the phase change material and expanded graphite (EG)/low-density polyethylene (LDPE) as the supporting matrix. To further enhance flame retardancy, ammonium polyphosphate (APP) and pentaerythritol (PER) were introduced as synergistic flame retardants. The optimized FSPCMs (60 wt% BO, 27 wt% LDPE, 3 wt% EG, 6 wt% APP, and 3 wt% PER) exhibited outstanding performance, achieving a latent heat of 122.6 J/g, a limiting oxygen index (LOI) of 23.3% (UL-94 V-0 rating), a 78.5% reduction in smoke production rate, a 68.3% decrease in smoke density, and a 77.2% photo-thermal conversion efficiency. A systematic analysis of BO’s molecular structure revealed its significant influence on phase change behavior and flame-retardant properties. The boric acid grafting strategy notably enhanced BO’s char-forming capability, elucidating its synergistic flame-retardant and smoke-suppression mechanisms. The developed FSPCMs hold promise to applied in energy storage and safety-critical applications.
研究领域:
材料科学
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能源存储
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阻燃技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）