High Uptake Capacity Research Articles

ZrO2 nanoparticles embedded in biochar modified with layered double oxides nanosheets for phosphorus removal by capacitive deionization

Phosphorus in excessive levels can cause eutrophication and destroy the aquatic ecological balance. In this work, a novel capacitive deionization (CDI) anode material was successfully fabricated for phosphorus capture by innovatively embedding ZrO2 in layered double oxides (LDO) - modified biochar (ZrO2@LDO/BC). This approach can overcome the traditional drawbacks of the lack of active sites for phosphorus capture in biochar and the poor electrical conductivity of ZrO2 and LDO. The optimal ZrO2@LDO/BC electrode possessed a high phosphorus uptake capacity (20.36 mg P/g) and low energy consumption (0.0287 kWh/m3 (0.0406 kWh/kg)), owing to its rich mesoporous structure, appropriate conductive framework, excellent electrochemical behavior, and sufficient phosphorus trapping sites. Moreover, a few critical experimental parameters were investigated for their impact on phosphorus removal. The mechanisms revealed were mainly related to the memory effect, electrostatic attractions, and ligand exchange. This work delivered new insights into biomass waste resource utilization and phosphorus control in sewage by constructing modified bagasse-derived carbon anodes.

Injectable gelatin/glucosamine cryogel microbeads as scaffolds for chondrocyte delivery in cartilage tissue engineering

In this study, we fabricate squeezable cryogel microbeads as injectable scaffolds for minimum invasive delivery of chondrocytes for cartilage tissue engineering applications. The microbeads with different glucosamine concentrations were prepared by combining the water-in-oil emulsion and cryogelation through crosslinking of gelatin with glutaraldehyde in the presence of glucosamine. The physicochemical characterization results show the successful preparation of cryogel microbeads with uniform shape and size, high porosity, large pore size, high water uptake capacity, and good injectability. In vitro analysis indicates proliferation, migration, and differentiated phenotype of rabbit chondrocytes in the cryogel scaffolds. The seeded chondrocytes in the cryogel scaffold can be delivered by injecting through an 18G needle to fully retain the cell viability. Furthermore, the incorporation of glucosamine in the cryogel promoted the differentiated phenotype of chondrocytes in a dose-dependent manner, from cartilage-specific gene expression and protein production. The in vivo study by injecting the cryogel microbeads into the subcutaneous pockets of nude mice indicates good retention ability as well as good biocompatibility and suitable biodegradability of the cryogel scaffold. Furthermore, the injected chondrocyte/cryogel microbead constructs can form ectopic functional neocartilage tissues following subcutaneous implantation in 21 days, as evidenced by histological and immunohistochemical analysis.

Homolog of Human placenta-specific gene 8, PcPLAC8-10, enhances cadmium uptake by Populus roots

Cadmium (Cd) pollution of soil occurs worldwide. Phytoremediation is an effective approach for cleaning up Cd polluted soil. Fast growing Populus species with high Cd uptake capacities are desirable for phytoremediation. Thus, it is important to elucidate the molecular functions of genes involved in Cd uptake by poplars. In this study, PcPLAC8–10, a homolog of Human placenta-specific gene 8 (PLAC8) implicated in Cd transport was functionally characterized in Populus × canescens. PcPLAC8–10 was transcriptionally induced in Cd-treated roots and it encoded a plasma membrane-localized transporter. PcPLAC8–10 exhibited Cd uptake activity when expressed in yeast cells. No difference in growth was observed between wild type (WT) and PcPLAC8–10-overexpressing poplars. PcPLAC8–10-overexpressing poplars exhibited increases in net Cd2+ influxes by 192% and Cd accumulation by 57% in the roots. However, similar reductions in biomass were found in WT and transgenic poplars when exposed to Cd. The complete motif of CCXXXXCPC in PcPLAC8–10 was essential for its Cd transport activity. These results suggest that PcPLAC8–10 is a plasma membrane-localized transporter responsible for Cd uptake in the roots and the complete CCXXXXCPC motif of PcPLAC8–10 plays a key role in its Cd transport activity in poplars.

Construction of camphor leaves-derived biochar@bismuth for the capture of gaseous iodine

Herein, Bi2O3 loaded with camphor leaves-derived biochar (Bi2O3@CLBC) was prepared to capture gaseous iodine. Bi2O3@CLBC was provided with a loose structure, high reactivity and relatively good thermal stability, leading to a high uptake capacity. The capture behavior of iodine on Bi2O3@CLBC was well described by the Pseudo-first-order and Langmuir models, demonstrating the occurrence of monolayer chemisorption on Bi2O3@CLBC. The maximum adsorption amount of Bi2O3@CLBC for iodine was 885.8 mg/g. The chemical uptake played a leading role in capturing volatile iodine, including the direct reaction between Bi2O3 particles and iodine vapor and the charge transfer between the –OH on biochar and iodine to generate a coordination complex. The pores on the surface of biochar could also capture some iodine through physical adsorption. In one word, this work was expected to offer a green treatment method for the excess of camphor leaves and an exceptional adsorbent for iodine uptake from spent fuel.

Reversed CO2/C2H2 separation with ultrahigh carbon dioxide adsorption capacity in Zn-based pillared metal-organic frameworks

The removal of CO2 impurities from CO2/C2H2 gas mixtures to obtain high-purity acetylene used for manufacturing of various commodity chemicals, is very important for the chemical purifying of acetylene. However, CO2 and C2H2 exhibit analogous physical properties as well as molecular sizes causing their separation to become an industrially challenging process, and developing energy-efficient CO2-selective adsorbents is a class of materials of vast value. In this work, a pillared-layer ultramicroporous metal-organic framework (MOF) constructed from zinc (Ⅱ) and triazolium planar layers with oxalic acid, which has been termed as CALF-20, can preferentially absorb CO2 from C2H2. Unique pore environment and electrostatic effects enable this material foremost capture CO2. CALF-20 shows higher affinities towards CO2 than C2H2 based on heats of adsorption computed from single-component adsorption isotherms. Grand Canonical Monte Carlo simulations confirm the affinity interactions and multiple host-guest interactions between CO2 and CALF-20. Sorption experiments revealed that CALF-20 has excellent trapping volume with extremely high CO2 uptake capacity (140.2 cm3 cm−3).

High-performance CO2 Capture from Air by Harnessing the Power of CaO- and Superbase Ionic Liquid-Engineered Sorbents.

Direct air capture (DAC) of CO2 by solid porous materials represents an attractive "negative emission" technology. However, state-of-the-art sorbents based on supported amines still suffer from unsolved high energy consumption and stability issues. Herein, taking clues from the CO2 interaction with superbase-derived ionic liquids (SILs), high-performance and tunable sorbents in DAC of CO2 was developed by harnessing the power of CaO- and SIL-engineered sorbents. Deploying mesoporous silica as the substrate, a thin CaO layer was first introduced to consume the surface-OH groups, and then active sites with different basicities (e.g., triazolate and imidazolate) were introduced as a uniformly distributed thin layer. The as-obtained sorbents displayed high CO2 uptake capacity via volumetric (at 0.4 mbar) and breakthrough test (400 ppm CO2 source), rapid interaction kinetics, facile CO2 releasing, and stable sorption/desorption cycles. Operando Diffuse Reflectance Infrared Fourier Transformation Spectroscopy (DRIFTS) analysis under simulated air atmosphere and solid-state Nuclear Magnetic Resonance (NMR) under 13CO2 atmosphere demonstrated the critical roles of the SIL species in low-concentration CO2 capture.The fundamental insights obtained in this work provide guidance on the development of high-performance sorbents in DAC of CO2 by leveraging the combined advantages of porous solid scaffolds and the unique features of CO2-philic ILs.

T-type capture site within highly stable bicarbazole-based metal–organic framework for C2H2 purification from CO2 and CH4

It is challenging to achieve high-purity acetylene (C2H2) from the methylene (CH4) and carbon dioxide (CO2), due to their similar molecular structure and physical properties. Adsorption utilized porous materials, such as metal–organic frameworks (MOFs), has been considered as cost- and energy-efficient technology to separate acetylene mixtures. Herein, we reported a highly stable MOF, [Zn6L4(Me2NH2+)4‧3H2O] (named FJU-83), featuring T-shaped functional capture sites explored for acetylene capture and separation. In addition, FJU-83a exhibits not only a high C2H2 uptake capacity of 122.9 cm3/g at 273 K, 1 bar, but also good C2H2/CH4 and C2H2/CO2 selectivity of 24 and 2.9 under moderate temperature and 1 bar, respectively. The high separation efficiency of the C2H2/CH4 and C2H2/CO2 are validated by dynamic fixed bed breakthrough experiments. The single crystal X-ray diffraction studies and Hirshfeld surface analysis revealed that T-type aromatic sites of FJU-83a can separate C2H2 from CH4 and CO2 through multiple C-H∙∙∙π and π∙∙∙π interactions.

A peptide-engineered alginate aerogel with synergistic blood-absorbing and platelet-binding capabilities to rapidly stop bleeding

Polysaccharide matrix infused with hemostasis-stimulating chemistry represents a critical medical need of bleeding management. Herein, we describe the development of a polysaccharide-peptide conjugate platform, an alginate engineered with fibrinogen-derived platelet-binding peptides (APE). The alginate backbone was found to allow for multivalent grafting of the peptides. Processing APE conjugate into crosslinked aerogels promoted platelet accumulation, leading to a significant reduction in the coagulation time of whole rabbit blood and improving the stability of the formed clot. The APE aerogels also exhibited a high porosity and fluid uptake capacity (>90 in weight ratio) as well as good biocompatibility in hemostasis. Furthermore, in vivo studies conducted in rat models of tail cut and hepatic hemorrhage showed that APE aerogels reduced bleeding time by >58 % and blood loss by >61 %. The platelet-enrichment capacity of the APE construct synergized by high absorbency in its aerogel form offers a prototype for customized polysaccharide hemostats.

“Functional connector” strategy on tunable organo-vermiculites: The superb adsorption towards Congo Red

With the increasingly worldwide concentration of environmental pollution, exploiting cost-effective adsorbents has been a research hotspot. Here we introduce novel “functional connector” amide-containing gemini surfactants (LDAB, LDAPP, LDAMP and LDABP) and apply to modify Na-vermiculite (Na-Vt) for Congo red (CR) removal. Chain amide as the functional connector in the modifier, increases 6.9 times of CR uptake than traditional organo-Vts, which is further enhanced by tunning the functional group of modifier spacers. Superb uptake of CR on organo-Vts reaches 1214.05, 1375.47 and 1449.80 mg/g, and the removal efficiencies achieve 80.94%, 91.70% and 96.65% on LDAB-Vt, LDAPP-Vt and LDAMP-Vt, respectively. Notably, the maximum experimental adsorption capacity of LDAPP-Vt is 1759.64 mg/g. These experimental values are among the highest reported CR adsorbents. A combination experimental and theoretical analysis is conducted to unveil the structure-adsorptivity relationship: (i) Adsorptivity enhancement of organo-Vts is more effectively by regulating functional chains than the functional spacer. (ii) para-substituted aromatic spacers own the best adsorptive configuration and strongest stability for π-π interaction. (iii) π-π interaction provided by isolated aromatic ring is stronger than biphenyl, whose steric hindrance depresses the adsorptivity. Results in this study not only explain a new “functional connector” strategy to Vt-based adsorbents, but also provide a practical designing strategy for organic adsorbents characterized with high uptake capacity.

Reticular Synthesis of Metal‐Organic Frameworks by 8‐Connected Quadrangular Prism Ligands for Water Harvesting

AbstractUtilization of rigid, highly connected organic linkers is critical for the reticular synthesis of functional metal–organic frameworks (MOFs). However, highly‐stable MOFs (e.g. Al/Cr/Zr‐based MOFs) based on rigid ligands with more than 6 coordinating functions have been rarely achieved thus far. Herein, we describe the construction of two bcu Zr‐based MOFs (named ZrMOF‐1 and ZrMOF‐2) from peripherally extended pentiptycene ligands (H8PEP‐1 and H8PEP‐2) with rigid quadrangular prism shape possessing 8 carboxylic groups at the prism vertices. Particularly, ZrMOF‐1 exhibits microporous structure with large Bruno‐Emmett‐Teller surface area and high water stability, endowing it a promising water harvesting material with a high water uptake capacity of 0.83 gH2O gMOF−1 at P/P0=0.90 and 25 °C, a steep uptake at a low P/P0 of 0.30, and excellent durability over 500 water adsorption‐desorption cycles. Moreover, self‐consistent charge density functional tight‐binding calculations were carried out, rationalizing the water adsorbing process and amount in ZrMOF‐1.

Reticular Synthesis of Metal-Organic Frameworks by 8-Connected Quadrangular Prism Ligands for Water Harvesting.

Utilization of rigid, highly connected organic linkers is critical for the reticular synthesis of functional metal-organic frameworks (MOFs). However, highly-stable MOFs (e.g. Al/Cr/Zr-based MOFs) based on rigid ligands with more than 6 coordinating functions have been rarely achieved thus far. Herein, we describe the construction of two bcu Zr-based MOFs (named ZrMOF-1 and ZrMOF-2) from peripherally extended pentiptycene ligands (H8 PEP-1 and H8 PEP-2) with rigid quadrangular prism shape possessing 8 carboxylic groups at the prism vertices. Particularly, ZrMOF-1 exhibits microporous structure with large Bruno-Emmett-Teller surface area and high water stability, endowing it a promising water harvesting material with a high water uptake capacity of 0.83 gH2O gMOF -1 at P/P0 =0.90 and 25 °C, a steep uptake at a low P/P0 of 0.30, and excellent durability over 500 water adsorption-desorption cycles. Moreover, self-consistent charge density functional tight-binding calculations were carried out, rationalizing the water adsorbing process and amount in ZrMOF-1.

Sodium tungstate as green cross‐linker to improve water absorbency of superabsorbent polymer

AbstractSuperabsorbent polymers (SAPs) are attracting more research interests in many fields mainly due to its distinguished water‐absorbing performance. Among all the factors that severely affecting water absorption of SAPs, cross‐linkers play a non‐negligible role in shaping the stable cross‐linked networks of SAPs. As for cross‐linking agents, previous studies have focused on the chemical cross‐linker as well as functional nanoparticle cross‐linker. Though their corresponding SAPs can achieve high water uptake capacity, the sustainable development of such SAPs was still limited by the natural defects of these cross‐linkers. Herein, we reported small‐molecule sodium tungstate (STD) as one novel cross‐linker to optimize water‐holding capabilities of SAPs. STD shows a high affinity to polymeric chains mainly via multiple hydrogen bonding interactions. The resultant poly(acrylic acid)/STD SAP exhibited a satisfactory water‐absorbing capacities with swelling ratios of 7527 g/g in distilled water, 95 g/g in 0.9 wt% NaCl solution and 2210 g/g in 3 wt% urea solution, respectively. In addition, such high water absorbency was achieved within SAP system just made up of a sole polymer and a sole cross‐linker, implying that STD can be used as novel cross‐linker to promote the green development of SAPs.

Triazine-containing polytriphenylimidazolium network for heterogeneous catalysis of CO2 conversion to cyclic carbonates

In this work, novel triazine-linked triphenylimidazole (TPIM) and triphenylimidazolium (TPIM-IL) monomers have been synthesized and fully characterized. Subsequently, their corresponding networks, namely PTPIM and PTPIM-IL, respectively, have been synthesized by Friedel-Crafts alkylation reaction. Owing to the dendritic-like, bulky and rigid structure of the two monomers, the resultant PTPIM and PTPIM-IL networks display relatively high specific surface areas of 982 m2/g and 570 m2/g, respectively. More importantly, PTPIM network can be readily transformed into PTPIM-IL network via a facile post-modification process. The presence of abundant CO2-affinity sites, i.e., imidazolium and triazine rings, together with high nucleophilicity of iodine anion endows PTPIM-IL network with not only high CO2 uptake capacity (2.69 mmol g−1), but also high activity toward the cycloaddition of CO2 to epoxides. For example, PTPIM-IL network has proven very effective in converting epibromohydrin to its corresponding cyclic carbonate under mild conditions (60 °C, 0.1 MPa), yielding quantitative conversion (99%) and selectivity (99%). The catalytic activity of PTPIM-IL network is superior to most previously reported imidazolium-based heterogeneous catalysts.

Novel Porous Organic Polymer for High-Performance Pb(II) Adsorption from Water: Synthesis, Characterization, Kinetic, and Isotherm Studies

The aim of the current study was to develop a novel triphenylaniline-based porous organic polymer (TPABPOP-1) by the Friedel–Crafts reaction for the efficient elimination of Pb(II) from an aqueous environment. XPS, FTIR, SEM, TGA, and 13C CP/MAS NMR analyses were applied to characterize the synthesized TPABPOP-1 polymer. The BET surface area of the TPABPOP-1 polymer was found to be 1290 m2/g. FTIR and XPS techniques proved the uptake of Pb(II) was successfully adsorbed onto TPABPOP-1. Using batch methods, Pb(II) ion adsorption on the TPABPOP-1 was studied at different equilibrium times, pH values, initial Pb(II) concentration, adsorption mass, and temperature. The outcomes exhibited that the optimum parameters were t: 180 min, m: 0.02 g, pH: 5, T: 308 K, and [Pb(II)]: 200 mg/L. Nonlinear isotherms and kinetics models were investigated. The Langmuir isotherm model suggested that the uptake of Pb(II) was favorable on the homogeneous surface of TPABPOP-1. Adsorption kinetics showed that the PFO model was followed. Pb(II) removal mechanisms of TPABPOP-1 may include surface adsorption and electrostatic attraction. The uptake capacity for Pb(II) was identified to be 472.20 mg/g. Thermodynamic factors exhibited that the uptake of Pb(II) was endothermic and spontaneous in standard conditions. Finally, this study provides effective triphenylaniline-based porous organic polymers (TPABPOP-1) as a promising adsorbent with high uptake capacity.

Green and sustainable nanoformulation of tebuconazole based on capsules of bionanocomposites halloysite/alginate

In this work, the synthesis of bionanocomposites based on halloysite/alginate with the fungicide tebuconazole (Tbz), as an active ingredient and its application as nanoformulation, was studied. The resultant nanoformulations were friendly to the environment and can be an alternative to increase the yiel of agricultural fields. To achieve this, the surface of the halloysite (Hal) was modified by the adsorption of five surfactants (one cationic and four nonionic) to obtain an organophilic organohalloysites (OHal). Adsorption isotherms and FTIR characterization demonstrated that OHal was obtained due to hydrogen bonding interactions between the nonionic surfactants and the Si-OH and Al-OH groups of the Hal, as well as due to cation exchange with the cationic surfactant. The Tbz was encapsulated in the OHal by adsorption. The mass of Tbz adsorbed was 6.73, 2.92, 4.41, 2.19, and 1.86 mg/g for the OHal with Span 20, Span 80, Tween 80, Tween 85, and HDTMA, respectively. This demonstrated that the surfactants with the highest uptake capacity in OHal have the lowest HLB (hydrophilic–lipophilic balance). The release kinetics of Tbz in the OHal occurred rapidly (approximately in 2 days), regardless of the surfactant type. Once encapsulated the Tbz with the alginate, the release time occurred between 5 and 15 days, decreasing the released quantity between 50 and 75%, evidencing a slow release and greater kinetics control. The confrontation of nanoformulations vs. Fusarium spp. delayed the fungus growth, like commercial tebuconazole does, corroborating the antifungal effect of the material, even though the nanopesticide synthesized in this work has 20 times less Tbz.

Efficient cavity-enhanced adsorption and recovery of low-concentration ammonia on pillar[5]arenes

Ammonia (NH3) capture has great implications for environmental protection and resource recovery. Developing effective and recyclable adsorbent materials to remove low-concentration NH3 in industrial waste gas is critical. Here, solid adsorbents per-hydroxylated pillar[5]arene (OHP[5]) and pillar[5]quinone (P[5]Q) with well-designed functional groups were synthesized and evaluated for NH3 adsorption. The results showed that both materials have high NH3 uptake capacity and excellent cycle stability. P[5]Q showed higher NH3 capacity (15.4 mmol/g) than OHP[5] (11.5 mmol/g) at ambient conditions (293.2 K and 1.0 bar). Dynamic breakthrough experiments showed that P[5]Q had good separation performance on low concentration NH3. Characterizations (including FTIR, SEM, and XPS) and density functional theory (DFT) studies revealed that the adsorption strength for NH3 on P[5]Q possessing CO groups was stronger than OHP[5] composed of phenolic hydroxyls. Also, the electron-accepting CO groups on P[5]Q could change the intramolecular charge distribution, in which an amount of NH3 enters and stores in the electron-deficient internal cavity of P[5]Q. It is demonstrated that P[5]Q with the suitable cavity has good potential for separating low concentration NH3 from industrial waste gas.

Field Calibration and PAS-SIM Model Evaluation of the XAD-Based Passive Air Sampler for Semi-Volatile Organic Compounds.

The use of passive air samplers (PAS) for semi-volatile organic compounds (SVOCs) continues to expand. To advance quantitative understanding of uptake kinetics, we calibrated the XAD-PAS, using a styrene-divinylbenzene sorbent, through a year-long side-by-side deployment with an active sampler. Twelve XAD-PASs, deployed in June 2020, were retrieved at 4-week intervals, while gas phase SVOCs were quantified in 48 consecutive week-long active samples taken from June 2020 to May 2021. Consistent with XAD's high uptake capacity, even relatively volatile SVOCs, such as hexachlorobutadiene, displayed linear uptake throughout the entire deployment. Sampling rates (SRs) range between 0.1 and 0.6 m3 day-1 for 26 SVOCs, including brominated flame retardants, organophosphate esters, and halogenated methoxylated benzenes. SRs are compared with experimental SRs reported previously. The ability of the existing mechanistic uptake model PAS-SIM to reproduce the observed uptake and SRs was evaluated. Agreement between simulated and measured uptake curves was reasonable but varied with compound volatility and the assumed stagnant air layer boundary thickness. Even though PAS-SIM succeeds in predicting the SR range for the studied SVOCs, it fails to capture the volatility dependence of the SR by underestimating the length of the linear uptake period and by failing to consider the kinetics of sorption.

Adsorption of toxic gases by metal-organic frameworks


 
 
 
 Along with global economic development and population growth, the discharge of highly toxic and corrosive anthropogenic byproducts into the atmosphere or aquatic habitats creates a serious threat to human health. In order to remove such byproducts, more attention should be paid to innovative materials with high uptake capacity and performance. Metal-organic frameworks (MOFs) are crystalline, porous, hybrid materials that are made up of organic ligands as linkers and metal cluster-based nodes. Because of their beneficial features such as their large surface area, tailorable pore sizes, structural diversity, catalytic activity, and wide range of chemical and physical properties, MOFs offer significant potential as adsorbents. As a result, these materials have drawn a significant amount of attention for the capture and/or detoxification of hazardous and toxic chemicals. This review will focus on recent advancements on MOF based experimental and computational studies related to the capture of toxic gases including hydrogen sulfide (H2S), ammonia (NH3) sulfur dioxide (SO2) carbon monoxide (CO), and nitrogen oxides (NOx).
 
 
 

Light Triggered Pore Size Tuning in Photoswitching Covalent Triazine Frameworks for Low Energy CO2 Capture.

Recently, photo switching porous materials have been widely reported for low energy costed CO2 capture and release via simply remoted light controlling method. However, most reported photo responsive CO2 adsorbents relied on metal organic framework (MOFs) functionalisation with photochromic moieties, and MOF adsorbents still suffered from chemically and thermally unstable issues. Thus, further metal free and highly stable organic photoresponsive adsorbents are necessary to be developed. CTFs, because of their high porosity and stability, have attracted great attention for CO2 capture. Considering the high CO2 uptake capacity and structural tunability of CTFs, it suggests high potential to fabricate the photoswitching CTF materials by the same functionalisation method as MOFs. Herein, the first series of photo switching CTFs were developed for low energy CO2 capture and release. Apart from that, the CO2 switching efficiency could be doubled either through the azobenzene numbers adjusting method or through the previously reported structural alleviation strategy. Furthermore, the pore size distribution of azobenzene functionalised PCTFs also could be tuned under UV exposure, which may contribute to the UV light induced decrease of CO2 uptake capacity. These photoswitching CTFs represented a new kind of porous polymers for low energy costed CO2 capture.

Light Triggered Pore Size Tuning in Photoswitching Covalent Triazine Frameworks for Low Energy CO2 Capture

AbstractRecently, photo switching porous materials have been widely reported for low energy costed CO2 capture and release via simply remoted light controlling method. However, most reported photo responsive CO2 adsorbents relied on metal organic framework (MOFs) functionalisation with photochromic moieties, and MOF adsorbents still suffered from chemically and thermally unstable issues. Thus, further metal free and highly stable organic photoresponsive adsorbents are necessary to be developed. CTFs, because of their high porosity and stability, have attracted great attention for CO2 capture. Considering the high CO2 uptake capacity and structural tunability of CTFs, it suggests high potential to fabricate the photoswitching CTF materials by the same functionalisation method as MOFs. Herein, the first series of photo switching CTFs were developed for low energy CO2 capture and release. Apart from that, the CO2 switching efficiency could be doubled either through the azobenzene numbers adjusting method or through the previously reported structural alleviation strategy. Furthermore, the pore size distribution of azobenzene functionalised PCTFs also could be tuned under UV exposure, which may contribute to the UV light induced decrease of CO2 uptake capacity. These photoswitching CTFs represented a new kind of porous polymers for low energy costed CO2 capture.