Materials Horizons
·
2023
·Vol. 10
·期 6
·2262-2270
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IF 13.3
Renjie Ding,Jinhua Xiong,Qian Yan,Zhong Chen,Zonglin Liu,Xu Zhao,Qingyu Peng,Xiaodong He
Acid rain is a worldwide problem because of the emission of acidic gases into the atmosphere, leading to the acidification of first-order streams and aggravation of fresh water shortage. Therefore, it is of great importance to develop an environmentally friendly method for removing acid from water. Herein, an advanced technology that can achieve aqueous acid purification using solar energy is realized with Ti3C2Tx MXene/polyaniline (PANI) hybrid non-woven fabrics (MPs) through interfacial solar vapor generation, with PANI acting as an acid absorber through the doping process. Benefiting from the porous structure and crumpled micro-surface of MPs, a high evaporation rate of 2.65 kg m−2 h−1 with an efficiency of 93.7% can be achieved under one-sun illumination. Moreover, MPs present an even higher evaporation rate of 2.83 kg m−2 h−1 in high concentration aqueous acid and can generate clean water with a pH higher than 6.5. More importantly, thanks to the unique reversible doping process of PANI, when used as an aqueous acid purifier, MPs show good stability and reusability after dedoping. Our work sheds light on an efficient strategy for dealing with aqueous acid and acid rain.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Jiandong Wang,Yuxing Jiang,Zhuangzhuang Tian,Jun Li,Yang Jin,Jianjun Chen,Yubin Wang
The traditional wet-process phosphoric acid has higher economic benefits than the thermal-process phosphoric acid, but introduces many metal ion impurities, which limits the application of phosphoric acid. In highly concentrated phosphoric acid solutions, phosphoric acid mainly exists in molecular form. Due to the surface charge and appropriate pore size of the nanofiltration (NF) membrane, it exhibits high selectivity for phosphoric acid and its impurities. However, because of the uncontrolled diffusion of monomers and rapid polymerization, the pore size distribution becomes highly uneven. Meanwhile the extremely low pH and high viscosity of the phosphoric acid compromise the stability and permeance of commercial membranes. We identified that the organic monomer benzene-1,3-disulfonyl chloride (BDSC) exhibits a capping effect when reacting with the aqueous phase of branched polyethyleneimine (PEI) which allows the newly formed membrane to regulate the subsequent diffusion and reaction of hexamethylene diisocyanate (HDI), thereby optimizing the membrane structure. By adjusting the concentration of BDSC, the pore size of the membrane layer was optimized. The final average pore size was determined to be 0.33 nm. The membrane exhibited an average ion rejection of over 65 % when tested in a 20 wt% P 2 O 5 solution, while maintaining a very low rejection rate of only 1.74 % for phosphorus. The permeance reached 1.21 L/h m 2 bar, surpassing that of traditional commercial membrane operating at less than 1 L/h m 2 bar under 10 wt% P 2 O 5 conditions. This study employed the capping effect to adjust the membrane structure and pore size, demonstrating that spatial sieving is the main mechanism for ions purification in phosphoric acid. Long-term acid resistance tests confirmed the stability of the poly (sulfonamide-urea) NF membrane during phosphoric acid purification process. This work shows that this new nanofiltration membrane exhibits promising prospects for application within acidic high-viscosity systems.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 53
·33646-33652
·
IF 3.361
Limin He,Yangdong Wang,Huanxin Gao,Zhicheng Liu,Zaiku Xie
The purification of crude terephthalic acid was performed by the hydrogenation of 4-carboxybenzaldehyde (4-CBA) over activated carbon (AC) supported Pd catalysts in industry. However, traditional Pd/AC catalysts usually suffer from low hydrogenation activity and poor thermal stability. Herein, nitrogen was incorporated into AC via a simple hydrothermal treatment of AC with urea as the nitrogen resource. The N doped AC contained pyridinic N, pyrrolic N, graphitic N and oxidized N. Wide characterizations revealed that N doping not only effectively improved the dispersion of Pd NPs but also increased the proportion of Pd0. In addition, N doping also enhanced the dissociative adsorption capacity of molecular hydrogen. More importantly, the resistance to sintering of Pd NPs was efficiently suppressed after N doping. As a result, N doped AC supported Pd showed both higher activity and better thermal stability than the N-free one.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Binbin He,Yuanzhi Zhu,Yun Zu,Yunxiang Nie,Yi Mei
Fluorine (F) is a high-value resource that has been overlooked in the production of wet process phosphoric acid (WPA) due to its high susceptibility to complexation with metal cationic impurities, hindering F efficient recovery and subsequent phosphoric acid purification. This paper firstly emphasizes on investigating the competitive complexation behavior between F species and metal cations (M = Al 3+ , Fe 3+ , Ca 2+ and Mg 2+ ) by designing a series of F-containing model solutions (as HF and/or H 2 SiF 6 ) with fixed combinations of metal cations. The results reveal that the complexation ability between metal cations and “free” F - species from HF dissociation and/or SiF 6 2- hydrolysis follows the order: Al 3+ > Fe 3+ > Ca 2+ > Mg 2+ . DFT calculation further confirms that the acid-soluble AlF 4 - and FeF 3 species with lower binding energies are the main obstacle to difficult recovery of F species in the WPA. Given the above facts, an efficient F recovery strategy is proposed by increasing initial F concentration (as HF and H 2 SiF 6 ) in industrial WPA for preferentially removing metal impurities in the forms of M−F precipitates (e.g., AlF 3 and CaF 2 ), according to the variations in distributions of M−F species under different n(F)/n(M) ratios predicted through establishment of mathematical models. The ultimate F recovery rate is greater than 95% by stripping process when initial HF concentration added is about 7.49 mol/L. This novel strategy has been successfully applied in phosphoric acid purification process.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chunling Chen,Hui Long,Yangyang Luo,Kuantao Zhang,Chongyu Du,Hongyan Pan,Qian Lin,Zheng Chen
The purification of wet-process phosphoric acid has always posed a challenge for both academic and industrial researchers. In order to address this issue, a treatment unit was developed to mitigate magnesium and aluminum impurities from industrial semi-aqueous wet process phosphoric acid (SWPPA) (39.4 wt% P 2 O 5 ) through ralstonite precipitation using Na + /F − as the precipitator (F − provided by HF). Thermodynamic analysis, DFT calculation and separation experiments results were used to investigate the impact of sodium sources properties on impurities removal rates and H 3 PO 4 yield. Additionally, the effects of reaction temperature, reaction time, precipitating agent dosage, and aging time on precipitation efficiency were also examined. The results show that the ability of sodium source to ionize Na + and react with H 3 PO 4 and HF plays a crucial role in determining the impurity removal performance of magnesium and aluminum. The precipitants NaCl and Na 2 CO 3 exhibit the highest removal rates for magnesium and aluminum, which is attributed to the easy ionization of Na + ions. In comparison to Na 2 CO 3 , the higher H 3 PO 4 yield with NaCl as precipitator can be achieved due to its lower nucleation rate and higher crystal growth rate in the phosphoric acid system. NaCl and HF as precipitants effectively reduces the concentrations of magnesium and aluminum in the untreated SWPPA solution from 23.47 g MgO/kg P 2 O 5 to 3.29 g MgO/kg P 2 O 5 , 48.98 g Al 2 O 3 /kg P 2 O 5 to 15.54 g Al 2 O 3 /kg P 2 O 5 . The removal rates for magnesium and aluminum are found to be 85.98% and 68.27%, respectively, with minimal residue of Na + /F − .
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Xiaoling Duan,Cunwen Wang,Tielin Wang,Xiaolin Xie,Xingping Zhou,Yunsheng Ye
Comb-shaped polysulfone anion exchange membranes (AEMs) containing various pendant alkyl side chains were synthesized and characterized. Ionic clusters aggregation is observed in transmission electron microscopy (TEM) image and small-angle X-ray scattering (SAXS). The comb-shaped quaternized ammonium polysulfone (Cx-QAPSU) membranes show enhanced dimensional stability and ultra-low membrane area resistance ( R m ). Notably, the C16-QAPSU with 16 carbon atoms has the best hydrophilic-hydrophobic phase separation structure and lowest R m of 2.5 Ω cm 2 despite low ion exchange capacity ( IEC ) of 1.55 mmol/g and swelling ratio of 5.3%. Moreover, comb-shaped AEMs show much higher tensile strength ( TS ) compared to QAPSU membrane under the same IEC level. The C16-QAPSU with lowest R m of 2.5 Ω cm 2 exhibits the highest TS of 16.7 MPa. These results indicate that the long alkyl side chains especially the length of the pendant side chain of Cx-QAPSU up to C16 achieve an electrochemical-mechanical balance of AEMs. In electro-electrodialysis systems, the comb-shaped AEMs exhibit higher purification efficiency of wet phosphoric acid than non-comb-shaped AEMs.
研究领域:
材料科学
·
化学工程
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）