Reactive distillation is a highly efficient process intensification technique, particularly suitable for reversible reactions. However, in the case of multi-step reversible reactions, mismatched reaction rates often result in low selectivity of intermediate products. This research proposes a reactive distillation approach with multiple reactive sections to address this challenge by incorporating an intermediate section within the reaction section. Using the synthesis of triethyl citrate as a case study, a reactive distillation with multiple reactive sections is designed, with process parameters optimized to minimize the total annual cost (TAC). Furthermore, a heat integration strategy is implemented, significantly reducing energy consumption. Compared to the reactive distillation with a single reaction section (RDC-SRS), the TAC is reduced by 7.5 % and 16.5 %, while the thermodynamic efficiencies are 13.82 % and 31.45 %, respectively. This configuration effectively decouples competing reactions, enhancing the selectivity of intermediate products. This work showcases multiple reactive sections of reactive distillation’s potential for complex, multi-step reversible reactions, offering insights into designing and optimizing sustainable, energy-efficient industrial processes.
{"title":"Reactive distillation with multiple reactive sections for the energy-efficient synthesis of triethyl citrate: process integration and optimization","authors":"Mingxin Hou, Qingjun Zhang, Hengyan Zhou, Chunjiang Liu, Wenyu Xiang","doi":"10.1016/j.seppur.2025.133181","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133181","url":null,"abstract":"Reactive distillation is a highly efficient process intensification technique, particularly suitable for reversible reactions. However, in the case of multi-step reversible reactions, mismatched reaction rates often result in low selectivity of intermediate products. This research proposes a reactive distillation approach with multiple reactive sections to address this challenge by incorporating an intermediate section within the reaction section. Using the synthesis of triethyl citrate as a case study, a reactive distillation with multiple reactive sections is designed, with process parameters optimized to minimize the total annual cost (TAC). Furthermore, a heat integration strategy is implemented, significantly reducing energy consumption. Compared to the reactive distillation with a single reaction section (RDC-SRS), the TAC is reduced by 7.5 % and 16.5 %, while the thermodynamic efficiencies are 13.82 % and 31.45 %, respectively. This configuration effectively decouples competing reactions, enhancing the selectivity of intermediate products. This work showcases multiple reactive sections of reactive distillation’s potential for complex, multi-step reversible reactions, offering insights into designing and optimizing sustainable, energy-efficient industrial processes.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"32 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-23DOI: 10.1016/j.seppur.2025.133184
Chenchen Song, Jian-Gang Guo, Xin-Ran Zhang
Graphene, an adsorbent material with excellent recyclability and large specific surface area, can effectively adsorb or desorb benzene-containing pollutant molecules in wastewater. In this study, we employed a combination of theoretical analysis, molecular dynamics simulations and atomic force microscopy experiments to elucidate the micromechanical mechanisms by which the ionic environment affects the π-π interactions between benzene and graphene. The results reveal that as the ion concentration increases, the adsorption behavior of graphene toward benzene rings is initially slightly enhanced but subsequently significantly inhibited. At the same ion concentration, higher ion valence promotes adsorption more effectively than lower ion valence. Comparative analysis demonstrates that ion concentration exerts a stronger influence on adsorption or desorption behavior than ion valence. The two primary mechanisms driving these phenomena are the impact of ions on the electrostatic potential charge distribution across the graphene surface and their competitive occupation of adsorption sites on graphene. These findings suggest that the amount of aromatic pollutant in wastewater can be precisely controlled by modulating the ionic environment. This study underscores graphene’s potential as a highly recyclable adsorbent material with significant promise for practical applications.
{"title":"Study on micromechanical mechanism of ionic environment affecting adsorption behavior between graphene and benzene","authors":"Chenchen Song, Jian-Gang Guo, Xin-Ran Zhang","doi":"10.1016/j.seppur.2025.133184","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133184","url":null,"abstract":"Graphene, an adsorbent material with excellent recyclability and large specific surface area, can effectively adsorb or desorb benzene-containing pollutant molecules in wastewater. In this study, we employed a combination of theoretical analysis, molecular dynamics simulations and atomic force microscopy experiments to elucidate the micromechanical mechanisms by which the ionic environment affects the π-π interactions between benzene and graphene. The results reveal that as the ion concentration increases, the adsorption behavior of graphene toward benzene rings is initially slightly enhanced but subsequently significantly inhibited. At the same ion concentration, higher ion valence promotes adsorption more effectively than lower ion valence. Comparative analysis demonstrates that ion concentration exerts a stronger influence on adsorption or desorption behavior than ion valence. The two primary mechanisms driving these phenomena are the impact of ions on the electrostatic potential charge distribution across the graphene surface and their competitive occupation of adsorption sites on graphene. These findings suggest that the amount of aromatic pollutant in wastewater can be precisely controlled by modulating the ionic environment. This study underscores graphene’s potential as a highly recyclable adsorbent material with significant promise for practical applications.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-22DOI: 10.1016/j.seppur.2025.133168
Jian Wang, Yonghong Wu, Yu Jiang, Bing Zhang
Here, a new kind of mixed matrix membranes (MMMs) were fabricated using Pebax1074 as continuous polymer matrix and poly (ethylene glycol)-modified montmorillonite (PEG-MMT) as dispersive dopant. The microscopic morphology, microstructure, surface functional groups, thermal stability, thermodynamic properties, and gas adsorption behaviors of the MMMs were characterized by scanning electron microscope, x-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimeter, and N2/CO2 adsorption, respectively. The effects of PEG-MMT amount, permeation temperature and permeation pressure on the microstructure and gas permeation properties of the as-prepared MMMs were mainly investigated. The results showed that the interlayer spacing of MMT is increased by intercalating with PEG. The resultant PEG-MMT presents an excellent dispersion and interfacial compatibility in Pebax membranes. The microstructure of the membrane tends to become more compact as the dopant content increases in the membrane. Meanwhile, both the CO2/N2 selectivity and CO2 permeability of MMMs show a trend of first growing and then descending. In addition, permeation at low pressure and low temperature is beneficial for the separation performance of the membrane for CO2/N2 system. Under the permeation condition of 30 °C and 0.1 MPa, an exceptional CO2/N2 selectivity is attained to 221.2 for the MMMs made of 2 % PEG-MMT dopant amount, along with the CO2 gas permeability of 148.3Barrer. Overall, the present MMMs hold a promising prospect with extremely commercial attractiveness in terms of CO2/N2 gas separation performance.
{"title":"Ultra-selective CO2/N2 separation membranes enabled by establishing delivery site-based CO2 transfer channels in Pebax membranes with PEG-montmorillonite","authors":"Jian Wang, Yonghong Wu, Yu Jiang, Bing Zhang","doi":"10.1016/j.seppur.2025.133168","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133168","url":null,"abstract":"Here, a new kind of mixed matrix membranes (MMMs) were fabricated using Pebax1074 as continuous polymer matrix and poly (ethylene glycol)-modified montmorillonite (PEG-MMT) as dispersive dopant. The microscopic morphology, microstructure, surface functional groups, thermal stability, thermodynamic properties, and gas adsorption behaviors of the MMMs were characterized by scanning electron microscope, x-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimeter, and N<sub>2</sub>/CO<sub>2</sub> adsorption, respectively. The effects of PEG-MMT amount, permeation temperature and permeation pressure on the microstructure and gas permeation properties of the as-prepared MMMs were mainly investigated. The results showed that the interlayer spacing of MMT is increased by intercalating with PEG. The resultant PEG-MMT presents an excellent dispersion and interfacial compatibility in Pebax membranes. The microstructure of the membrane tends to become more compact as the dopant content increases in the membrane. Meanwhile, both the CO<sub>2</sub>/N<sub>2</sub> selectivity and CO<sub>2</sub> permeability of MMMs show a trend of first growing and then descending. In addition, permeation at low pressure and low temperature is beneficial for the separation performance of the membrane for CO<sub>2</sub>/N<sub>2</sub> system. Under the permeation condition of 30 °C and 0.1 MPa, an exceptional CO<sub>2</sub>/N<sub>2</sub> selectivity is attained to 221.2 for the MMMs made of 2 % PEG-MMT dopant amount, along with the CO<sub>2</sub> gas permeability of 148.3Barrer. Overall, the present MMMs hold a promising prospect with extremely commercial attractiveness in terms of CO<sub>2</sub>/N<sub>2</sub> gas separation performance.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"37 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-22DOI: 10.1016/j.seppur.2025.133173
Wenkang Niv, Xu Sun, Xiaoyan Zhang, Zizhong Zhang, Ke Wang, Wenxin Dai, Xianzhi Fu Resource
Photocatalytic CO2 reduction offers a promising solution to both the energy crisis and environmental issues. However, existing photocatalysts for simulating photosynthesis at ambient temperature exhibit limited conversion efficiency. In this study, we leveraged the photothermal effect of MnO2 to significantly increase the surface temperature of the catalyst under full-spectrum irradiation, thereby markedly enhancing CO2 conversion efficiency. Photocatalytic performance evaluations and characterization results revealed that the temperature elevation accelerated the generation and transfer of photogenerated electrons. Furthermore, Cd single atoms (Cd SAs) were successfully incorporated onto the MnO2 surface through in-situ redox reaction. Various characterizations and first-principles calculations demonstrated that the incorporation of Cd SAs in Cd-MnO2 created effective atomic-level site for water adsorption and dissociation, providing abundant *H species for CO2 reduction. Cd SAs also modulate the local electronic environment, facilitating CO2 adsorption at adjacent Mn sites and lowering the energy barrier for *COOH formation. Moreover, the spin polarization induced by Cd SAs suppresses photogenerated charge recombination while promoting cyclic regeneration of active Mn sites. Furthermore, the weak adsorption of CO on the catalyst hinders its hydrogenation to CH4, achieving exceptional CO selectivity (98 %) with a production rate of 318.2 μmol·g−1·h−1. These advantages enhanced thermally-assisted photocatalytic performance, providing valuable insights for improving the efficiency of photocatalytic CO2 reduction.
{"title":"Cadmium single atoms enhance full-spectrum solar photothermal-driven photocatalytic CO2 reduction in H2O vapor","authors":"Wenkang Niv, Xu Sun, Xiaoyan Zhang, Zizhong Zhang, Ke Wang, Wenxin Dai, Xianzhi Fu Resource","doi":"10.1016/j.seppur.2025.133173","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133173","url":null,"abstract":"Photocatalytic CO<sub>2</sub> reduction offers a promising solution to both the energy crisis and environmental issues. However, existing photocatalysts for simulating photosynthesis at ambient temperature exhibit limited conversion efficiency. In this study, we leveraged the photothermal effect of MnO<sub>2</sub> to significantly increase the surface temperature of the catalyst under full-spectrum irradiation, thereby markedly enhancing CO<sub>2</sub> conversion efficiency. Photocatalytic performance evaluations and characterization results revealed that the temperature elevation accelerated the generation and transfer of photogenerated electrons. Furthermore, Cd single atoms (Cd SAs) were successfully incorporated onto the MnO<sub>2</sub> surface through in-situ redox reaction. Various characterizations and first-principles calculations demonstrated that the incorporation of Cd SAs in Cd-MnO<sub>2</sub> created effective atomic-level site for water adsorption and dissociation, providing abundant *H species for CO<sub>2</sub> reduction. Cd SAs also modulate the local electronic environment, facilitating CO<sub>2</sub> adsorption at adjacent Mn sites and lowering the energy barrier for *COOH formation. Moreover, the spin polarization induced by Cd SAs suppresses photogenerated charge recombination while promoting cyclic regeneration of active Mn sites. Furthermore, the weak adsorption of CO on the catalyst hinders its hydrogenation to CH<sub>4</sub>, achieving exceptional CO selectivity (98 %) with a production rate of 318.2 μmol·g<sup>−1</sup>·h<sup>−1</sup>. These advantages enhanced thermally-assisted photocatalytic performance, providing valuable insights for improving the efficiency of photocatalytic CO<sub>2</sub> reduction.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"6 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The light-driven conversion of CO2 to dimethyl carbonate (DMC) represents a promising green and sustainable pathway for achieving dual-carbon goals. However, the inherent difficulty in activating CO2 molecules results in low DMC yields when synthesizing DMC from CO2 and methanol (CH3OH) under light-driven conditions. In this study, the activation of CO2 and CH3OH is enhanced by modulating the number of hydroxyl groups and the concentration of oxygen vacancies on the surface of spindle-like CeO2-x through the introduction of cetyltrimethylammonium bromide (CTAB). Photothermal catalytic experiments show that the optimal CTAB-modified CeO2-x achieves excellent DMC yield of 5.26 mmol·g−1 under mild conditions (0.1 MPa, 120℃). The X-ray photoelectron spectroscopy and CO2 temperature-programmed desorption results demonstrate that CTAB modification increases the number of hydroxyl groups and oxygen vacancies on the CeO2-x surface, which improves the effective activation of CO2 to form the reactive intermediates such as *HCO3– and *CO2. Notably, the increased hydroxyl groups promote the dissociation of CH3OH into *CH3O. Meanwhile, isotopic labeling and in situ infrared characterization confirm the light-driven reaction pathway of CO2 and CH3OH, involving the oxidation of CH3OH to *CH2OH via photogenerated holes, followed by rapid coupling with *CO2 to generate the reactive intermediate (CH3OCOO*). These findings provide new insights into the rational design and construction of CeO2-based catalysts to achieve high yields of DMC under mild conditions.
{"title":"Photothermal catalytic synthesis of DMC from CO2 and CH3OH at atmospheric pressure: Synergistic effect of surface hydroxyl groups and oxygen vacancies on spindle-like CeO2-x","authors":"Guoqiang Zhang, Xiya Zhao, Xiushuai Guan, Xiaokun Wang, Xiaoyang Wang, Xiaochao Zhang","doi":"10.1016/j.seppur.2025.133166","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133166","url":null,"abstract":"The light-driven conversion of CO<sub>2</sub> to dimethyl carbonate (DMC) represents a promising green and sustainable pathway for achieving dual-carbon goals. However, the inherent difficulty in activating CO<sub>2</sub> molecules results in low DMC yields when synthesizing DMC from CO<sub>2</sub> and methanol (CH<sub>3</sub>OH) under light-driven conditions. In this study, the activation of CO<sub>2</sub> and CH<sub>3</sub>OH is enhanced by modulating the number of hydroxyl groups and the concentration of oxygen vacancies on the surface of spindle-like CeO<sub>2-x</sub> through the introduction of cetyltrimethylammonium bromide (CTAB). Photothermal catalytic experiments show that the optimal CTAB-modified CeO<sub>2-x</sub> achieves excellent DMC yield of 5.26 mmol·g<sup>−1</sup> under mild conditions (0.1 MPa, 120℃). The X-ray photoelectron spectroscopy and CO<sub>2</sub> temperature-programmed desorption results demonstrate that CTAB modification increases the number of hydroxyl groups and oxygen vacancies on the CeO<sub>2-x</sub> surface, which improves the effective activation of CO<sub>2</sub> to form the reactive intermediates such as *HCO<sub>3</sub>– and *CO<sub>2</sub>. Notably, the increased hydroxyl groups promote the dissociation of CH<sub>3</sub>OH into *CH<sub>3</sub>O. Meanwhile, isotopic labeling and in situ infrared characterization confirm the light-driven reaction pathway of CO<sub>2</sub> and CH<sub>3</sub>OH, involving the oxidation of CH<sub>3</sub>OH to *CH<sub>2</sub>OH via photogenerated holes, followed by rapid coupling with *CO<sub>2</sub> to generate the reactive intermediate (CH<sub>3</sub>OCOO*). These findings provide new insights into the rational design and construction of CeO<sub>2</sub>-based catalysts to achieve high yields of DMC under mild conditions.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"52 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-22DOI: 10.1016/j.seppur.2025.133170
Xingyu Wang, Jie Zhou, Shuangjia Weng, Xiaoxiao Lu, Yang Xia
BiOCl-based materials are promising for chloride-ion storage and saline water deionization; however, their limited intercalation contributions and slow reaction kinetics hinder cyclability and chloride-ion storage capacities. In this work, crystal plane engineering using a simple pH adjustment method optimizes the crystallographic orientation and grain sizes of BiOCl, resulting in improved chloride-ion storage performances in aqueous-based electrochemical systems. When paired with an Ag electrode, samples demonstrate an exceptional chloride-ion storage capacity of 122.61 mAh g−1 at 0.3 A g−1 with excellent capacity retention of 90.1 % after 120 cycles and exhibit a rate capacity of 85.12 mAh g−1 at 2 A g−1. In desalination systems (paired with a Prussian blue electrode), they achieve a desalination capacity of 74.75 mg g−1 at 1.2 V and maintain a capacity of 58.47 mg g−1 after 30 cycles. DFT calculations and experiments reveal that increased exposure of the (110) crystal plane could slightly reduce chloride ion diffusion coefficients and hinder charge transfer while enhancing pseudocapacitive contributions. In-situ XRD results further confirm that crystallographic orientation promotes a higher proportion of intercalation reactions, improving electrode utilization and reversibility. This trade-off between ion diffusion, pseudocapacity, and reaction reversibility leads to superior electrochemical performances, providing insights for optimizing BiOCl-based anodes for long-term stability and multifunctional applications in chloride-ion storage and saline water deionization.
{"title":"Crystal plane engineering of BiOCl for enhanced chloride-ion storage and saline water deionization performances","authors":"Xingyu Wang, Jie Zhou, Shuangjia Weng, Xiaoxiao Lu, Yang Xia","doi":"10.1016/j.seppur.2025.133170","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133170","url":null,"abstract":"BiOCl-based materials are promising for chloride-ion storage and saline water deionization; however, their limited intercalation contributions and slow reaction kinetics hinder cyclability and chloride-ion storage capacities. In this work, crystal plane engineering using a simple pH adjustment method optimizes the crystallographic orientation and grain sizes of BiOCl, resulting in improved chloride-ion storage performances in aqueous-based electrochemical systems. When paired with an Ag electrode, samples demonstrate an exceptional chloride-ion storage capacity of 122.61 mAh g<sup>−1</sup> at 0.3 A g<sup>−1</sup> with excellent capacity retention of 90.1 % after 120 cycles and exhibit a rate capacity of 85.12 mAh g<sup>−1</sup> at 2 A g<sup>−1</sup>. In desalination systems (paired with a Prussian blue electrode), they achieve a desalination capacity of 74.75 mg g<sup>−1</sup> at 1.2 V and maintain a capacity of 58.47 mg g<sup>−1</sup> after 30 cycles. DFT calculations and experiments reveal that increased exposure of the (110) crystal plane could slightly reduce chloride ion diffusion coefficients and hinder charge transfer while enhancing pseudocapacitive contributions. <em>In-situ</em> XRD results further confirm that crystallographic orientation promotes a higher proportion of intercalation reactions, improving electrode utilization and reversibility. This trade-off between ion diffusion, pseudocapacity, and reaction reversibility leads to superior electrochemical performances, providing insights for optimizing BiOCl-based anodes for long-term stability and multifunctional applications in chloride-ion storage and saline water deionization.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"7 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The electrochemical reduction of nitrate (NO3−RR) is a promising strategy for producing value-added ammonia while addressing water pollution and promoting sustainable nitrogen management. Inspired by the reduction process from CuO to Cu, we proposed a novel electrochemically driven NO3−-assisted directed evolution strategy to construct Cu/Cu2O heterojunctions for enhanced NO3−RR performance. A copper foam-supported copper oxides (CuxO) catalyst was synthesized via an electrochemical reconstruction method in the presence of nitrate. Comprehensive characterization using SEM, XPS, and XRD demonstrated that nitrate concentration plays a crucial role in tuning the structure, surface chemistry, and oxidation state of CuxO/CF. In a 0.5 M Na2SO4 solution containing 0.01 M KNO3, the optimized Cu-0.1 catalyst exhibited significantly enhanced NO3−RR activity, achieving a high NH4+ yield rate of 4.33 mg·h−1·cm−2 at –1.0 V vs. RHE and a Faradaic efficiency of 78.0 % at –0.8 V vs. RHE. Furthermore, DFT calculations revealed that nitrate concentration was the critical factor in regulating Cu2O content and controlling its growth during the formation of Cu/Cu2O heterojunctions. The enhanced NO3−RR activity was attributed to the synergistic effect between NO3− adsorption on the Cu2O(111) crystal plane and NH3 desorption on the Cu(111) plane.
{"title":"Constructing high activity Cu/Cu2O via nitrate-assisted directed evolution for enhanced electro catalytic nitrate-to-ammonia conversion","authors":"Zhun You, Jiao Shen, Senhao Wang, Yuan Wang, Ying Liang, Shaojun Yuan","doi":"10.1016/j.seppur.2025.133165","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133165","url":null,"abstract":"The electrochemical reduction of nitrate (NO<sub>3</sub><sup>−</sup>RR) is a promising strategy for producing value-added ammonia while addressing water pollution and promoting sustainable nitrogen management. Inspired by the reduction process from CuO to Cu, we proposed a novel electrochemically driven NO<sub>3</sub><sup>−</sup>-assisted directed evolution strategy to construct Cu/Cu<sub>2</sub>O heterojunctions for enhanced NO<sub>3</sub><sup>−</sup>RR performance. A copper foam-supported copper oxides (Cu<sub>x</sub>O) catalyst was synthesized via an electrochemical reconstruction method in the presence of nitrate. Comprehensive characterization using SEM, XPS, and XRD demonstrated that nitrate concentration plays a crucial role in tuning the structure, surface chemistry, and oxidation state of Cu<sub>x</sub>O/CF. In a 0.5 M Na<sub>2</sub>SO<sub>4</sub> solution containing 0.01 M KNO<sub>3</sub>, the optimized Cu-0.1 catalyst exhibited significantly enhanced NO<sub>3</sub><sup>−</sup>RR activity, achieving a high NH<sub>4</sub><sup>+</sup> yield rate of 4.33 mg·h<sup>−1</sup>·cm<sup>−2</sup> at –1.0 V vs. RHE and a Faradaic efficiency of 78.0 % at –0.8 V vs. RHE. Furthermore, DFT calculations revealed that nitrate concentration was the critical factor in regulating Cu<sub>2</sub>O content and controlling its growth during the formation of Cu/Cu<sub>2</sub>O heterojunctions. The enhanced NO<sub>3</sub><sup>−</sup>RR activity was attributed to the synergistic effect between NO<sub>3</sub><sup>−</sup> adsorption on the Cu<sub>2</sub>O(111) crystal plane and NH<sub>3</sub> desorption on the Cu(111) plane.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"32 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-22DOI: 10.1016/j.seppur.2025.133158
R. Priyadharshini, S.SD. Elanchezhiyan, Subbaiah Muthu Prabhu, S. Meenakshi
In an aqueous environment, chromium is often recognized as a toxic oxyanion that poses a significant threat to living organisms because of its carcinogenic nature. The removal of hexavalent chromium (Cr(VI)) from an aqueous medium is essential to protect the environment and human health. This investigation explores the elimination of Cr(VI) ions from water by employing an adsorption technique utilizing a biopolymeric hybrid composite consisting of copper-incorporated lanthanum oxide@Chitosan (CuxLa2-xO3@Chi). The as-prepared materials were comprehensively analyzed using SEM, EDX, FTIR, XRD, BET, TGA, and XPS analysis. A systematic approach was used to optimize the batch adsorption parameters in order to ensure the maximum adsorption capacity of prepared adsorbent materials. The prepared CuxLa2-xO3@Chi composite exhibited a prominent adsorption capacity of 123.45 mg/g at pH 4.0 within 120 min. Adsorption kinetics and isotherm studies reveal that the adsorption of Cr(VI) process follows pseudo-second-order kinetics and Langmuir isotherm models, respectively. This suggests that the adsorption process occurs in a monolayer formation and involves a chemisorption mechanism. Mechanistic investigations reveal that the synergistic effect of electrostatic attraction, surface complexation, and adsorption-coupled reduction mechanism enhanced the adsorption of Cr(VI) ions from aqueous media. The selectivity and stability of the CuxLa2-xO3@Chi composite were investigated through competing and reusability experiments. The findings demonstrated outstanding selectivity in the presence of various competing ions and maintained good stability over five consecutive cycles. Therefore, the prepared CuxLa2-xO3@Chi composite proved outstanding adsorption ability against Cr(VI) ions and can be used as a technological reference in real-world water treatment.
{"title":"Bimetallic oxide integrated chitosan matrix for adsorption coupled reduction of Cr(VI) from aqueous solution","authors":"R. Priyadharshini, S.SD. Elanchezhiyan, Subbaiah Muthu Prabhu, S. Meenakshi","doi":"10.1016/j.seppur.2025.133158","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133158","url":null,"abstract":"In an aqueous environment, chromium is often recognized as a toxic oxyanion that poses a significant threat to living organisms because of its carcinogenic nature. The removal of hexavalent chromium (Cr(VI)) from an aqueous medium is essential to protect the environment and human health. This investigation explores the elimination of Cr(VI) ions from water by employing an adsorption technique utilizing a biopolymeric hybrid composite consisting of copper-incorporated lanthanum oxide@Chitosan (Cu<sub>x</sub>La<sub>2-x</sub>O<sub>3</sub>@Chi). The as-prepared materials were comprehensively analyzed using SEM, EDX, FTIR, XRD, BET, TGA, and XPS analysis. A systematic approach was used to optimize the batch adsorption parameters in order to ensure the maximum adsorption capacity of prepared adsorbent materials. The prepared Cu<sub>x</sub>La<sub>2-x</sub>O<sub>3</sub>@Chi composite exhibited a prominent adsorption capacity of 123.45 mg/g at pH 4.0 within 120 min. Adsorption kinetics and isotherm studies reveal that the adsorption of Cr(VI) process follows pseudo-second-order kinetics and Langmuir isotherm models, respectively. This suggests that the adsorption process occurs in a monolayer formation and involves a chemisorption mechanism. Mechanistic investigations reveal that the synergistic effect of electrostatic attraction, surface complexation, and adsorption-coupled reduction mechanism enhanced the adsorption of Cr(VI) ions from aqueous media. The selectivity and stability of the Cu<sub>x</sub>La<sub>2-x</sub>O<sub>3</sub>@Chi composite were investigated through competing and reusability experiments. The findings demonstrated outstanding selectivity in the presence of various competing ions and maintained good stability over five consecutive cycles. Therefore, the prepared Cu<sub>x</sub>La<sub>2-x</sub>O<sub>3</sub>@Chi composite proved outstanding adsorption ability against Cr(VI) ions and can be used as a technological reference in real-world water treatment.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"25 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-22DOI: 10.1016/j.seppur.2025.133124
Miao Sun, Xinyao Ji, Meichen Li, Yuan Yu, Kai Zhang, Chengyu Wang, Haiyue Yang
Solar-driven evaporation technology is considered an effective approach for obtaining fresh water. However, unnecessary heat loss and inefficient energy utilization decrease evaporation rate of solar evaporator. Herein, a multifunctional integrated aerogel-based evaporator is fabricated with anisotropic porous structure and low thermal diffusivity by the freeze-casting method, which not only reduces heat loss in evaporation process but also enables the formation of a power generation system and a desalination and cultivation system. The oriented pores of the aerogel-based evaporator enhance light refraction, promoting light absorption, which is beneficial for capillary action in seawater desalination. Additionally, the aerogel-based evaporator with anisotropic low thermal conductivities (0.066 W m−1 K−1 at axial direction and 0.058 W m−1 K−1 at radial direction) effectively minimizes thermal loss to the surrounding water. Under 1 sun irradiation (1 kW m−2), the aerogel-based evaporator exhibits the evaporation rate of 2.00 kg m−2h−1 and 92.83 % evaporation efficiency. This effectiveness of the power generation system strategy in thermoelectric generation results in an output power of 1.14 W m−2, with a voltage of 92.9 mV and a current of 11.04 mA. Furthermore, a desalination and cultivation system are designed to enable concurrent evaporation, condensation, and collection of freshwater, demonstrating its potential for agriculture applications. This work demonstrates the feasibility of achieving high evaporation rates in seawater desalination through the design of an insulating aerogel evaporator with low thermal conductivity and provides a solution for alleviating freshwater shortages in remote coastal areas.
{"title":"Anisotropic solar evaporator with low thermal conductivity for desalination, thermoelectric generation and cultivation","authors":"Miao Sun, Xinyao Ji, Meichen Li, Yuan Yu, Kai Zhang, Chengyu Wang, Haiyue Yang","doi":"10.1016/j.seppur.2025.133124","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133124","url":null,"abstract":"Solar-driven evaporation technology is considered an effective approach for obtaining fresh water. However, unnecessary heat loss and inefficient energy utilization decrease evaporation rate of solar evaporator. Herein, a multifunctional integrated aerogel-based evaporator is fabricated with anisotropic porous structure and low thermal diffusivity by the freeze-casting method, which not only reduces heat loss in evaporation process but also enables the formation of a power generation system and a desalination and cultivation system. The oriented pores of the aerogel-based evaporator enhance light refraction, promoting light absorption, which is beneficial for capillary action in seawater desalination. Additionally, the aerogel-based evaporator with anisotropic low thermal conductivities (0.066 W m<sup>−1</sup> K<sup>−1</sup> at axial direction and 0.058 W m<sup>−1</sup> K<sup>−1</sup> at radial direction) effectively minimizes thermal loss to the surrounding water. Under 1 sun irradiation (1 kW m<sup>−2</sup>), the aerogel-based evaporator exhibits the evaporation rate of 2.00 kg m<sup>−2</sup>h<sup>−1</sup> and 92.83 % evaporation efficiency. This effectiveness of the power generation system strategy in thermoelectric generation results in an output power of 1.14 W m<sup>−2</sup>, with a voltage of 92.9 mV and a current of 11.04 mA. Furthermore, a desalination and cultivation system are designed to enable concurrent evaporation, condensation, and collection of freshwater, demonstrating its potential for agriculture applications. This work demonstrates the feasibility of achieving high evaporation rates in seawater desalination through the design of an insulating aerogel evaporator with low thermal conductivity and provides a solution for alleviating freshwater shortages in remote coastal areas.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"219 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Visible-light-driven CO2 conversion into industry-beneficial chemicals is regarded as a sustainable environmental technology. However, its effectiveness was hindered by poor CO2 adsorption activation and high rates of electron-hole recombination. To address these challenges, novel Z-scheme Ni(OH)2/CoTiO3 (NO/CTO) heterostructure photocatalysts are synthesized via a facile chemical precipitation method, which demonstrate significant photocatalytic activity potential under visible light. In this study, the incorporation of Ni(OH)2 enhances the specific surface area of the photocatalyst, thereby augmenting its CO2 adsorption capacity. The optimized NO/CTO (0.2NO/CTO) photocatalysts exhibit the highest activity and CO selectivity, with CO production rates and selectivity reaching 10441 mmol·g−1·h−1 and 85.2 %, respectively, which are 4.0 and 5.8 times higher than those of pristine CoTiO3. In-situ Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFT) analysis reveals effective CO2 adsorption on the NO/CTO surface and the formation mechanism of intermediates in the reaction. X-ray photoelectron spectroscopy (XPS) analysis indicates strong electronic coupling between Ni(OH)2 and CoTiO3. Density Functional Theory (DFT) simulations further elucidate the generation of interfacial electric field (IEF), facilitating the formation of an effective Z-scheme heterojunction. This study provides a promising strategy to produce low-cost transition metal based nanocomposites for efficient CO2 photoreduction.
{"title":"Efficient visible-light-driven CO2 reduction on Z-scheme Ni(OH)2/CoTiO3 nanocomposites with robust interfacial electric field","authors":"Lanyang Wang, Chao Qu, Fanwei Meng, Decai Yang, Zezhong Zhao, Qing Ye","doi":"10.1016/j.seppur.2025.133169","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133169","url":null,"abstract":"Visible-light-driven CO<sub>2</sub> conversion into industry-beneficial chemicals is regarded as a sustainable environmental technology. However, its effectiveness was hindered by poor CO<sub>2</sub> adsorption activation and high rates of electron-hole recombination. To address these challenges, novel Z-scheme Ni(OH)<sub>2</sub>/CoTiO<sub>3</sub> (NO/CTO) heterostructure photocatalysts are synthesized via a facile chemical precipitation method, which demonstrate significant photocatalytic activity potential under visible light. In this study, the incorporation of Ni(OH)<sub>2</sub> enhances the specific surface area of the photocatalyst, thereby augmenting its CO<sub>2</sub> adsorption capacity. The optimized NO/CTO (0.2NO/CTO) photocatalysts exhibit the highest activity and CO selectivity, with CO production rates and selectivity reaching 10441 mmol·g<sup>−1</sup>·h<sup>−1</sup> and 85.2 %, respectively, which are 4.0 and 5.8 times higher than those of pristine CoTiO<sub>3</sub>. In-situ Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFT) analysis reveals effective CO<sub>2</sub> adsorption on the NO/CTO surface and the formation mechanism of intermediates in the reaction. X-ray photoelectron spectroscopy (XPS) analysis indicates strong electronic coupling between Ni(OH)<sub>2</sub> and CoTiO<sub>3</sub>. Density Functional Theory (DFT) simulations further elucidate the generation of interfacial electric field (IEF), facilitating the formation of an effective Z-scheme heterojunction. This study provides a promising strategy to produce low-cost transition metal based nanocomposites for efficient CO<sub>2</sub> photoreduction.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"35 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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