Mohamed Gamal Mohamed , Yang‐Chin Kao , Shi-Quan Hong , Aya Farouk Farghal , Shiao-Wei Kuo
{"title":"无金属β-酮胺基共轭微孔聚合物:高效降解有机污染物的稳健光催化剂的合理设计","authors":"Mohamed Gamal Mohamed , Yang‐Chin Kao , Shi-Quan Hong , Aya Farouk Farghal , Shiao-Wei Kuo","doi":"10.1016/j.jtice.2025.106434","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>The rapid growth of industrialization has led to increased discharge of dye-laden wastewater, posing serious threats to aquatic ecosystems and water sustainability. Synthetic dyes like rhodamine B (RhB) and methylene blue (MB), known for their stable conjugated structures, resist biodegradation and persist in the environment. Their accumulation in water bodies harms aquatic life and can indirectly impact human health.</div></div><div><h3>Methods</h3><div>A series of metal-free β-ketoenamine-based conjugated microporous polymers (CMPs) was synthesized via Schiff-base polycondensation of an amine-terminated azobenzene monomer (AZO-2NH<sub>2</sub>), 2,4,6-triformylphloroglucinol (TFP), and a diamino-substituted dibenzothiophene dioxide monomer (DBTD-2NH<sub>2</sub>) under solvothermal conditions. By varying the molar feed ratio of AZO-2NH<sub>2</sub>:TFP:DBTD-2NH<sub>2</sub> (2:2:1, 1.5:2:1.5, and 1:2:2), three CMP (AZO<sub>2</sub>-TFP<sub>2</sub>-DBTD<sub>1</sub>, AZO<sub>1.5</sub>-TFP<sub>2</sub>-DBTD<sub>1.5</sub>, AZO<sub>1</sub>-TFP<sub>2</sub>-DBTD<sub>2</sub>) with tunable porosity, electronic structure, and morphology were obtained. Comprehensive spectroscopic characterization confirmed the complete formation of β-ketoenamine linkages, the successful incorporation of azo and DBTD motifs, and high chemical purity.</div></div><div><h3>Significant Findings</h3><div>Thermogravimetric analysis of AZO-TFP-DBTD CMPs revealed outstanding thermal stability (<em>T</em><sub>d10</sub> up to 461 °C, char yield up to 60.8 wt%). Nitrogen sorption studies demonstrated that our AZO-TFP-DBTD CMPs exhibited hierarchical micro- and mesoporosity, with Brunauer–Emmett–Teller (BET) surface areas ranging from 110 to 125 m<sup>2</sup> g<sup>−1</sup> and dominant pore diameters of 1.7-2.0 nm. Ultraviolet photoelectron spectroscopy (UPS) and Tauc plot analyses of AZO-TFP-DBTD CMPs revealed a progressive deepening of the highest occupied molecular orbital (HOMO) level and a narrowing of the optical bandgaps (2.12-2.19 eV) as the DBTD content increased, thereby enhancing visible-light absorption. Photocatalytic evaluation using methylene blue (MB) and rhodamine B (RhB) as model dyes under visible irradiation revealed that AZO<sub>1</sub>-TFP<sub>2</sub>-DBTD<sub>2</sub> outperformed its counterparts, achieving greater than 98% degradation within 60 min and pseudo-first-order rate constants of up to 0.067 min<sup>−1</sup>. Mechanistic studies identified singlet oxygen and photo-generated electrons as the primary reactive species. Recyclability tests of AZO<sub>1</sub>-TFP<sub>2</sub>-DBTD<sub>2</sub> confirmed excellent stability over three cycles with <10% loss in activity. This work highlights the effectiveness of molecular engineering and monomer stoichiometry in optimizing AZO-TFP-DBTD CMP photocatalysts for water remediation.</div></div>","PeriodicalId":381,"journal":{"name":"Journal of the Taiwan Institute of Chemical Engineers","volume":"179 ","pages":"Article 106434"},"PeriodicalIF":6.3000,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Metal-free β-ketoenamine-based conjugated microporous polymers: rational design of robust photocatalysts for efficient organic pollutant degradation\",\"authors\":\"Mohamed Gamal Mohamed , Yang‐Chin Kao , Shi-Quan Hong , Aya Farouk Farghal , Shiao-Wei Kuo\",\"doi\":\"10.1016/j.jtice.2025.106434\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Background</h3><div>The rapid growth of industrialization has led to increased discharge of dye-laden wastewater, posing serious threats to aquatic ecosystems and water sustainability. Synthetic dyes like rhodamine B (RhB) and methylene blue (MB), known for their stable conjugated structures, resist biodegradation and persist in the environment. Their accumulation in water bodies harms aquatic life and can indirectly impact human health.</div></div><div><h3>Methods</h3><div>A series of metal-free β-ketoenamine-based conjugated microporous polymers (CMPs) was synthesized via Schiff-base polycondensation of an amine-terminated azobenzene monomer (AZO-2NH<sub>2</sub>), 2,4,6-triformylphloroglucinol (TFP), and a diamino-substituted dibenzothiophene dioxide monomer (DBTD-2NH<sub>2</sub>) under solvothermal conditions. By varying the molar feed ratio of AZO-2NH<sub>2</sub>:TFP:DBTD-2NH<sub>2</sub> (2:2:1, 1.5:2:1.5, and 1:2:2), three CMP (AZO<sub>2</sub>-TFP<sub>2</sub>-DBTD<sub>1</sub>, AZO<sub>1.5</sub>-TFP<sub>2</sub>-DBTD<sub>1.5</sub>, AZO<sub>1</sub>-TFP<sub>2</sub>-DBTD<sub>2</sub>) with tunable porosity, electronic structure, and morphology were obtained. Comprehensive spectroscopic characterization confirmed the complete formation of β-ketoenamine linkages, the successful incorporation of azo and DBTD motifs, and high chemical purity.</div></div><div><h3>Significant Findings</h3><div>Thermogravimetric analysis of AZO-TFP-DBTD CMPs revealed outstanding thermal stability (<em>T</em><sub>d10</sub> up to 461 °C, char yield up to 60.8 wt%). Nitrogen sorption studies demonstrated that our AZO-TFP-DBTD CMPs exhibited hierarchical micro- and mesoporosity, with Brunauer–Emmett–Teller (BET) surface areas ranging from 110 to 125 m<sup>2</sup> g<sup>−1</sup> and dominant pore diameters of 1.7-2.0 nm. Ultraviolet photoelectron spectroscopy (UPS) and Tauc plot analyses of AZO-TFP-DBTD CMPs revealed a progressive deepening of the highest occupied molecular orbital (HOMO) level and a narrowing of the optical bandgaps (2.12-2.19 eV) as the DBTD content increased, thereby enhancing visible-light absorption. Photocatalytic evaluation using methylene blue (MB) and rhodamine B (RhB) as model dyes under visible irradiation revealed that AZO<sub>1</sub>-TFP<sub>2</sub>-DBTD<sub>2</sub> outperformed its counterparts, achieving greater than 98% degradation within 60 min and pseudo-first-order rate constants of up to 0.067 min<sup>−1</sup>. Mechanistic studies identified singlet oxygen and photo-generated electrons as the primary reactive species. Recyclability tests of AZO<sub>1</sub>-TFP<sub>2</sub>-DBTD<sub>2</sub> confirmed excellent stability over three cycles with <10% loss in activity. This work highlights the effectiveness of molecular engineering and monomer stoichiometry in optimizing AZO-TFP-DBTD CMP photocatalysts for water remediation.</div></div>\",\"PeriodicalId\":381,\"journal\":{\"name\":\"Journal of the Taiwan Institute of Chemical Engineers\",\"volume\":\"179 \",\"pages\":\"Article 106434\"},\"PeriodicalIF\":6.3000,\"publicationDate\":\"2025-09-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of the Taiwan Institute of Chemical Engineers\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1876107025004845\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, CHEMICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Taiwan Institute of Chemical Engineers","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1876107025004845","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
Metal-free β-ketoenamine-based conjugated microporous polymers: rational design of robust photocatalysts for efficient organic pollutant degradation
Background
The rapid growth of industrialization has led to increased discharge of dye-laden wastewater, posing serious threats to aquatic ecosystems and water sustainability. Synthetic dyes like rhodamine B (RhB) and methylene blue (MB), known for their stable conjugated structures, resist biodegradation and persist in the environment. Their accumulation in water bodies harms aquatic life and can indirectly impact human health.
Methods
A series of metal-free β-ketoenamine-based conjugated microporous polymers (CMPs) was synthesized via Schiff-base polycondensation of an amine-terminated azobenzene monomer (AZO-2NH2), 2,4,6-triformylphloroglucinol (TFP), and a diamino-substituted dibenzothiophene dioxide monomer (DBTD-2NH2) under solvothermal conditions. By varying the molar feed ratio of AZO-2NH2:TFP:DBTD-2NH2 (2:2:1, 1.5:2:1.5, and 1:2:2), three CMP (AZO2-TFP2-DBTD1, AZO1.5-TFP2-DBTD1.5, AZO1-TFP2-DBTD2) with tunable porosity, electronic structure, and morphology were obtained. Comprehensive spectroscopic characterization confirmed the complete formation of β-ketoenamine linkages, the successful incorporation of azo and DBTD motifs, and high chemical purity.
Significant Findings
Thermogravimetric analysis of AZO-TFP-DBTD CMPs revealed outstanding thermal stability (Td10 up to 461 °C, char yield up to 60.8 wt%). Nitrogen sorption studies demonstrated that our AZO-TFP-DBTD CMPs exhibited hierarchical micro- and mesoporosity, with Brunauer–Emmett–Teller (BET) surface areas ranging from 110 to 125 m2 g−1 and dominant pore diameters of 1.7-2.0 nm. Ultraviolet photoelectron spectroscopy (UPS) and Tauc plot analyses of AZO-TFP-DBTD CMPs revealed a progressive deepening of the highest occupied molecular orbital (HOMO) level and a narrowing of the optical bandgaps (2.12-2.19 eV) as the DBTD content increased, thereby enhancing visible-light absorption. Photocatalytic evaluation using methylene blue (MB) and rhodamine B (RhB) as model dyes under visible irradiation revealed that AZO1-TFP2-DBTD2 outperformed its counterparts, achieving greater than 98% degradation within 60 min and pseudo-first-order rate constants of up to 0.067 min−1. Mechanistic studies identified singlet oxygen and photo-generated electrons as the primary reactive species. Recyclability tests of AZO1-TFP2-DBTD2 confirmed excellent stability over three cycles with <10% loss in activity. This work highlights the effectiveness of molecular engineering and monomer stoichiometry in optimizing AZO-TFP-DBTD CMP photocatalysts for water remediation.
期刊介绍:
Journal of the Taiwan Institute of Chemical Engineers (formerly known as Journal of the Chinese Institute of Chemical Engineers) publishes original works, from fundamental principles to practical applications, in the broad field of chemical engineering with special focus on three aspects: Chemical and Biomolecular Science and Technology, Energy and Environmental Science and Technology, and Materials Science and Technology. Authors should choose for their manuscript an appropriate aspect section and a few related classifications when submitting to the journal online.