Separation and Purification Technology最新文献_第2页

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

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133166

Guoqiang Zhang , Xiya Zhao , Xiushuai Guan , Xiaokun Wang , Xiaoyang Wang , Xiaochao Zhang

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 CeO_2-x through the introduction of cetyltrimethylammonium bromide (CTAB). Photothermal catalytic experiments show that the optimal CTAB-modified CeO_2-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 CeO_2-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.

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引用次数: 0

Cadmium single atoms enhance full-spectrum solar photothermal-driven photocatalytic CO2 reduction in H2O vapor

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133173

Wenkang Ni , Xu Sun , Xiaoyan Zhang , Zizhong Zhang , Ke Wang , Wenxin Dai , Xianzhi Fu

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 Ni , Xu Sun , Xiaoyan Zhang , Zizhong Zhang , Ke Wang , Wenxin Dai , Xianzhi Fu","doi":"10.1016/j.seppur.2025.133173","DOIUrl":"10.1016/j.seppur.2025.133173","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"369 ","pages":"Article 133173"},"PeriodicalIF":8.1,"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}

引用次数: 0

Crystal plane engineering of BiOCl for enhanced chloride-ion storage and saline water deionization performances 为提高氯离子储存和盐水去离子性能而进行的生物OCl 晶体平面工程设计

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 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":"10.1016/j.seppur.2025.133170","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"369 ","pages":"Article 133170"},"PeriodicalIF":8.1,"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}

引用次数: 0

Novel S-scheme heterojunction of red mud-based Fe2O3/Co-Al-LDH for the photo-Fenton degradation of gatifloxacin under visible light

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133160

Yuliang He , Guangtao Wei , Ni Wang, Junchi Gu, Linye Zhang, Wenhui Mu

Gatifloxacin (GAT), as one of the fourth-generation fluoroquinolone antibiotics, has been widely used in the medical industry to treat bacterial infections, while also was increasingly detected in aquatic environments. Red Mud (RM) was one kind of industrial solid waste residue discharged from the extraction process of alumina by Bayer technology. In this study, a novel RM-based heterojunction catalyst composed of Fe₂O₃ and Co-Al layered double hydroxide (Fe/Co-Al-LDH/RM) was fabricated using RM as raw material through a simple Mechanochemical Synthesis (MCS) method, and Fe/Co-Al-LDH/RM was then used as catalyst for photo-Fenton system to degrade GAT in aquatic environments under visible light (Vis + Fe/Co-Al-LDH/RM + H₂O₂ system). After reacting for 120 min, 94.0 % of GAT (20 mg/L, 300 mL) could be removed with the optimum reaction conditions as follows: [Fe/Co-Al-LDH/RM] = 0.03 g/L, [H₂O₂] = 90 mmol/L and initial pH = 6.5. The constructed reaction system was proven to be effective in degrading GAT in various natural water sources. The characterizations revealed that the action of MCS could significantly improve the physicochemical and photoelectrochemical properties of Fe/Co-Al-LDH/RM, and density functional theory (DFT) calculation proved that Fe/Co-Al-LDH/RM exhibited an unique S-type charge transfer pathway under visible light. The quenching experiments showed that Co(IV) and Fe(IV) were the predominant active species for GAT degradation in the weak acidic system of Vis + Fe/Co-Al-LDH/RM + H₂O₂, while h⁺ and ·OH were the predominant active species for GAT degradation in the strong acidic system of Vis + Fe/Co-Al-LDH/RM + H₂O₂. This study not only uses industrial waste RM as raw material to successfully synthesize a catalyst with S-scheme heterojunctions though a simple MCS method, but also advances the development of GAT degradation technology in photo-Fenton system, achieving the goal of “using waste to treat waste”.

{"title":"Novel S-scheme heterojunction of red mud-based Fe2O3/Co-Al-LDH for the photo-Fenton degradation of gatifloxacin under visible light","authors":"Yuliang He , Guangtao Wei , Ni Wang, Junchi Gu, Linye Zhang, Wenhui Mu","doi":"10.1016/j.seppur.2025.133160","DOIUrl":"10.1016/j.seppur.2025.133160","url":null,"abstract":"<div><div>Gatifloxacin (GAT), as one of the fourth-generation fluoroquinolone antibiotics, has been widely used in the medical industry to treat bacterial infections, while also was increasingly detected in aquatic environments. Red Mud (RM) was one kind of industrial solid waste residue discharged from the extraction process of alumina by Bayer technology. In this study, a novel RM-based heterojunction catalyst composed of Fe2O3 and Co-Al layered double hydroxide (Fe/Co-Al-LDH/RM) was fabricated using RM as raw material through a simple Mechanochemical Synthesis (MCS) method, and Fe/Co-Al-LDH/RM was then used as catalyst for photo-Fenton system to degrade GAT in aquatic environments under visible light (Vis + Fe/Co-Al-LDH/RM + H2O2 system). After reacting for 120 min, 94.0 % of GAT (20 mg/L, 300 mL) could be removed with the optimum reaction conditions as follows: [Fe/Co-Al-LDH/RM] = 0.03 g/L, [H2O2] = 90 mmol/L and initial pH = 6.5. The constructed reaction system was proven to be effective in degrading GAT in various natural water sources. The characterizations revealed that the action of MCS could significantly improve the physicochemical and photoelectrochemical properties of Fe/Co-Al-LDH/RM, and density functional theory (DFT) calculation proved that Fe/Co-Al-LDH/RM exhibited an unique S-type charge transfer pathway under visible light. The quenching experiments showed that Co(IV) and Fe(IV) were the predominant active species for GAT degradation in the weak acidic system of Vis + Fe/Co-Al-LDH/RM + H2O2, while h+ and ·OH were the predominant active species for GAT degradation in the strong acidic system of Vis + Fe/Co-Al-LDH/RM + H2O2. This study not only uses industrial waste RM as raw material to successfully synthesize a catalyst with S-scheme heterojunctions though a simple MCS method, but also advances the development of GAT degradation technology in photo-Fenton system, achieving the goal of “using waste to treat waste”.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"369 ","pages":"Article 133160"},"PeriodicalIF":8.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869931","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}

引用次数: 0

Efficient recovery of iron and alumina from red mud by alkali-enhanced magnetization reduction

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133146

Yafei Qi, Xiaolin Pan, Haozhuo Zheng, Zhicheng Zhang, Haiyan Yu

In order to achieve the efficient abatement of red mud and recover its valuable metals, the thermodynamics, mineral transformation and reaction mechanism of alkali-enhanced magnetization reduction were systematically investigated. The thermodynamic results indicate that the reaction sequence of iron oxides with the increasing CO partial pressure follows: Fe₂O₃ → Fe₃O₄ → FeO → Fe, and NaOH exhibits stronger reactivity than Na₂CO₃, which can react more easily with the non-ferrous oxides of red mud. The increase of roasting temperature and NaOH dosage promotes the conversation of Na_1.75Al_1.75Si_0.25O₄ to Na_1.95Al_1.95Si_0.05O₄, and the excessive NaOH and coal additions lead to the transformation of Fe₃O₄ to NaFe_0.75Al_0.25O₂ and FeO, which significantly deteriorates the iron recovery property. The non-magnetic compounds of SiO₂ and CaTiO₃ can be separated by the magnetic separation. The optimal conditions for the magnetization reduction were obtained, and the Al₂O₃ and Na₂O recovery efficiencies of roasting product are 81.56 % and 90.97 %. The TFe, Al₂O₃ and Na₂O contents of iron concentrate are 55.21 %, 3.87 % and 0.82 %, while the corresponding yield and iron recovery efficiency are 87.97 % and 90.37 %.

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引用次数: 0

Constructing high activity Cu/Cu2O via nitrate-assisted directed evolution for enhanced electro catalytic nitrate-to-ammonia conversion

IF 8.6 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133165

Zhun You, Jiao Shen, Senhao Wang, Yuan Wang, Ying Liang, Shaojun Yuan

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 (Cu_xO) 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_xO/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.

硝酸盐的电化学还原（NO3-RR）是一种生产高附加值氨的可行策略，同时还能解决水污染问题并促进可持续的氮管理。受从 CuO 到 Cu 的还原过程的启发，我们提出了一种新型的电化学驱动 NO3 辅助定向进化策略，以构建 Cu/Cu2O 异质结，从而提高 NO3-RR 的性能。在硝酸盐存在下，通过电化学重构方法合成了泡沫铜支撑的铜氧化物（CuxO）催化剂。利用 SEM、XPS 和 XRD 进行的综合表征表明，硝酸盐浓度在调整 CuxO/CF 的结构、表面化学性质和氧化态方面起着至关重要的作用。在含有 0.01 M KNO3 的 0.5 M Na2SO4 溶液中，优化的 Cu-0.1 催化剂表现出显著增强的 NO3-RR 活性，在-1.0 V 相对于 RHE 时，NH4+ 产率高达 4.33 mg-h-1-cm-2，在-0.8 V 相对于 RHE 时，法拉第效率为 78.0%。此外，DFT 计算显示，在 Cu/Cu2O 异质结的形成过程中，硝酸盐浓度是调节 Cu2O 含量和控制其生长的关键因素。NO3-RR 活性的增强归因于 NO3- 在 Cu2O(111) 晶面上的吸附和 NH3 在 Cu(111) 平面上的解吸之间的协同效应。

{"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 (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.","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}

引用次数: 0

Efficient glycolysis of polyurethane (PU) foam using biobased crude glycerol for oil–water separation sponge and rigid PU foam preparation: Optimization and techno-economic evaluation

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133174

Kai Fu , Liutao Hou , Xingchen Yang , Yucheng Lin , Huijuan Tian , Shiqiang Zhao , Chun Chang , Xiuli Han

Tremendous efforts have been dedicated to recycling waste polyurethane foam (WPUF) and developing an efficient and eco-friendly method for separating oil–water mixtures. However, the research on the application of high-value WPUF was insufficient. Herein, we proposed using biobased crude glycerol (CG) for split-phase glycolysis of WPUF. The upper polyol (Pol A) was used to prepare a porous sponge for the field of oil–water separation, and the lower-phase product (LPP) was converted into rigid polyurethane (PU) foam with thermal insulation properties. The research investigated the effects of various reaction conditions on the glycolysis of PU foam and optimized the formulations of the porous hydrophobic sponge and rigid PU foam. The porous sponge demonstrated a high degree of porosity and a remarkably low density of 31.9 kg/m³, along with a notably efficient affinity for absorbing oils and organic solvents. It could absorb oil and organic solvents up to 27–94 times its weight, achieve rapid absorption within 5 s, and demonstrate superior reusability for 100 cycles. The prepared rigid PU foam showed compressive strengths exceeding 150 kPa and met the standards for thermal insulation materials. Besides, a techno-economic evaluation of the glycolysis process demonstrates the project’s profitability and viability. These results showed that CG could achieve efficient glycolysis and high-value application of WPUF. This study provides a new method for producing porous sponges for oil–water separation and rigid PU foam with thermal insulation properties.

{"title":"Efficient glycolysis of polyurethane (PU) foam using biobased crude glycerol for oil–water separation sponge and rigid PU foam preparation: Optimization and techno-economic evaluation","authors":"Kai Fu , Liutao Hou , Xingchen Yang , Yucheng Lin , Huijuan Tian , Shiqiang Zhao , Chun Chang , Xiuli Han","doi":"10.1016/j.seppur.2025.133174","DOIUrl":"10.1016/j.seppur.2025.133174","url":null,"abstract":"<div><div>Tremendous efforts have been dedicated to recycling waste polyurethane foam (WPUF) and developing an efficient and eco-friendly method for separating oil–water mixtures. However, the research on the application of high-value WPUF was insufficient. Herein, we proposed using biobased crude glycerol (CG) for split-phase glycolysis of WPUF. The upper polyol (Pol A) was used to prepare a porous sponge for the field of oil–water separation, and the lower-phase product (LPP) was converted into rigid polyurethane (PU) foam with thermal insulation properties. The research investigated the effects of various reaction conditions on the glycolysis of PU foam and optimized the formulations of the porous hydrophobic sponge and rigid PU foam. The porous sponge demonstrated a high degree of porosity and a remarkably low density of 31.9 kg/m3, along with a notably efficient affinity for absorbing oils and organic solvents. It could absorb oil and organic solvents up to 27–94 times its weight, achieve rapid absorption within 5 s, and demonstrate superior reusability for 100 cycles. The prepared rigid PU foam showed compressive strengths exceeding 150 kPa and met the standards for thermal insulation materials. Besides, a techno-economic evaluation of the glycolysis process demonstrates the project’s profitability and viability. These results showed that CG could achieve efficient glycolysis and high-value application of WPUF. This study provides a new method for producing porous sponges for oil–water separation and rigid PU foam with thermal insulation properties.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"369 ","pages":"Article 133174"},"PeriodicalIF":8.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869933","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}

引用次数: 0

Synergistic boron doping and Tin-Bismuth bimetallic interface for lowering the two Free-Energy barriers in electrocatalytic CO2 reduction to formate

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133175

Junying Yi, Xiaomin Wu, Bihong Lv, Huawang Zhao, Guohua Jing

Bismuth-based catalysts for the electrocatalytic reduction of CO₂ to formate are regarded as a highly promising strategy for the conversion of surplus CO₂ into valuable chemical commodities. Currently, lowering the free-energy barriers of the activation of CO₂ and *OCHO is highly desirable and challenging. In this study, a catalyst rich in boron (B)-doped and Sn-Bi bimetallic interface is constructed. The utilisation of X-ray photoelectron spectroscopy (XPS), Bader charge analysis and projected density of states (PDOS) analysis reveal that the Bi sites adjacent to boron exhibited a positive valence state. This valence characteristic significantly facilitates the adsorption of CO₂ on the surface, resulting in the generation of the *CO₂^– intermediate. Meanwhile, the bismetallic interface between Bi and Sn induces an electron-rich Bi sites, which subtly enhances the interaction between the active sites and the *OCHO intermediate, thereby reducing the free-energy barrier. The synergistic effect of B doping and the bimetallic interface strategically modulates the local electronic structure of Bi to reduce the two free-energy barriers, including the rate-determining step. Comprehensive electrochemical analysis, coupled with corresponding characterization tests and theoretical calculations, demonstrates that it significantly lowers the two free-energy barriers, achieving an impressive maximum Faraday efficiency of 98.4 % at −1.0 V vs. RHE.

{"title":"Synergistic boron doping and Tin-Bismuth bimetallic interface for lowering the two Free-Energy barriers in electrocatalytic CO2 reduction to formate","authors":"Junying Yi, Xiaomin Wu, Bihong Lv, Huawang Zhao, Guohua Jing","doi":"10.1016/j.seppur.2025.133175","DOIUrl":"10.1016/j.seppur.2025.133175","url":null,"abstract":"<div><div>Bismuth-based catalysts for the electrocatalytic reduction of CO2 to formate are regarded as a highly promising strategy for the conversion of surplus CO2 into valuable chemical commodities. Currently, lowering the free-energy barriers of the activation of CO2 and *OCHO is highly desirable and challenging. In this study, a catalyst rich in boron (B)-doped and Sn-Bi bimetallic interface is constructed. The utilisation of X-ray photoelectron spectroscopy (XPS), Bader charge analysis and projected density of states (PDOS) analysis reveal that the Bi sites adjacent to boron exhibited a positive valence state. This valence characteristic significantly facilitates the adsorption of CO2 on the surface, resulting in the generation of the *CO2– intermediate. Meanwhile, the bismetallic interface between Bi and Sn induces an electron-rich Bi sites, which subtly enhances the interaction between the active sites and the *OCHO intermediate, thereby reducing the free-energy barrier. The synergistic effect of B doping and the bimetallic interface strategically modulates the local electronic structure of Bi to reduce the two free-energy barriers, including the rate-determining step. Comprehensive electrochemical analysis, coupled with corresponding characterization tests and theoretical calculations, demonstrates that it significantly lowers the two free-energy barriers, achieving an impressive maximum Faraday efficiency of 98.4 % at −1.0 V vs. RHE.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"369 ","pages":"Article 133175"},"PeriodicalIF":8.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869934","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}

引用次数: 0

Improving electron-ion transportation in BiOI via Fe-doping for efficient I− extraction by photo-assisted electrochemically switched ion exchange

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 10.1016/j.seppur.2025.133171

Shangjun Wang , Xiaowei An , Huixin Zhang , Jing Zhang , Peifen Wang , Xuli Ma , Xiao Du , Xiaogang Hao , Guoqing Guan , Abuliti Abudula , Gang Yang

Low electronic and ionic conductivity of intrinsic BiOI limit its application in iodide ion (I⁻) extraction via photo-assisted electrochemically switched ion exchange (P-ESIX). Herein, we prepared a Fe-doped BiOI (Fe-BiOI) photoelectric film electrode using a facile grinding method to enhance I⁻ extraction performance via P-ESIX. Physicochemical characterization combined with density functional theory (DFT) calculations reveal that Fe substitutes part of Bi in BiOI, resulting in stronger Fe-O-Bi bonds compared to Bi-O-Bi, which causes contraction of the BiOI lattice. Additionally, the d electron-rich Fe increases the density of delocalized electrons, enhancing the electronic conductivity of BiOI. DFT calculations also confirm that Fe-doping reduces the I⁻ migration energy barrier, thereby increasing ionic conductivity. As a result of improved electron–ion transportation, under optimized conditions with an Fe doping ratio of 0.5 wt% and an applied adsorption potential of 0.6 V (vs. Ag/AgCl), the Fe-BiOI film electrode demonstrated I⁻ adsorption capacities of 172 mg·g⁻¹ in the conventional ESIX process and 312 mg·g⁻¹ in the P-ESIX process. The photo-assisted efficiency reached 81.4 %, which is significantly higher than the 59.3 % efficiency of pristine BiOI. Moreover, the Fe-BiOI film electrode demonstrates high selectivity for I⁻ over competing anions, with separation factors of 4.28 for I⁻/F⁻, 4.72 for I⁻/Cl⁻, and 1.69 for I⁻/Br⁻, respectively. After 10 consecutive adsorption–desorption cycles, the I⁻ adsorption capacity retains 87.7 % of its initial value, indicating good regeneration performance and cycling stability. This research provides new insights into the design of photoelectric materials for iodine extraction from aqueous solutions.

{"title":"Improving electron-ion transportation in BiOI via Fe-doping for efficient I− extraction by photo-assisted electrochemically switched ion exchange","authors":"Shangjun Wang , Xiaowei An , Huixin Zhang , Jing Zhang , Peifen Wang , Xuli Ma , Xiao Du , Xiaogang Hao , Guoqing Guan , Abuliti Abudula , Gang Yang","doi":"10.1016/j.seppur.2025.133171","DOIUrl":"10.1016/j.seppur.2025.133171","url":null,"abstract":"<div><div>Low electronic and ionic conductivity of intrinsic BiOI limit its application in iodide ion (I−) extraction via photo-assisted electrochemically switched ion exchange (P-ESIX). Herein, we prepared a Fe-doped BiOI (Fe-BiOI) photoelectric film electrode using a facile grinding method to enhance I− extraction performance via P-ESIX. Physicochemical characterization combined with density functional theory<svg><path></path></svg> (DFT) calculations reveal that Fe substitutes part of Bi in BiOI, resulting in stronger Fe-O-Bi bonds compared to Bi-O-Bi, which causes contraction of the BiOI lattice. Additionally, the d electron-rich Fe increases the density of delocalized electrons, enhancing the electronic conductivity of BiOI. DFT calculations also confirm that Fe-doping reduces the I− migration energy barrier, thereby increasing ionic conductivity. As a result of improved electron–ion transportation, under optimized conditions with an Fe doping ratio of 0.5 wt% and an applied adsorption potential of 0.6 V (vs. Ag/AgCl), the Fe-BiOI film electrode demonstrated I− adsorption capacities of 172 mg·g−1 in the conventional ESIX process and 312 mg·g−1 in the P-ESIX process. The photo-assisted efficiency reached 81.4 %, which is significantly higher than the 59.3 % efficiency of pristine BiOI. Moreover, the Fe-BiOI film electrode demonstrates high selectivity for I− over competing anions, with separation factors of 4.28 for I−/F−, 4.72 for I−/Cl−, and 1.69 for I−/Br−, respectively. After 10 consecutive adsorption–desorption cycles, the I− adsorption capacity retains 87.7 % of its initial value, indicating good regeneration performance and cycling stability. This research provides new insights into the design of photoelectric materials for iodine extraction from aqueous solutions.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"369 ","pages":"Article 133171"},"PeriodicalIF":8.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870007","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}

引用次数: 0

Bimetallic oxide integrated chitosan matrix for adsorption coupled reduction of Cr(VI) from aqueous solution 吸附耦合还原水溶液中六价铬的双金属氧化物集成壳聚糖基质

IF 8.6 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2025-04-22 DOI: 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 (Cu_xLa_2-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 Cu_xLa_2-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 Cu_xLa_2-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 Cu_xLa_2-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 (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.","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}

引用次数: 0