Aptamer‐modified magnetic metal‐organic framework MIL‐101 for highly efficient and selective enrichment of ochratoxin A

A facile and efficient strategy is developed to modify aptamers on the surface of the magnetic metal‐organic framework MIL‐101 for the rapid magnetic solid‐phase extraction of ochratoxin A. To the best of our knowledge, this is the first attempt to create a robust aptamer‐modified magnetic MIL‐101 with covalent bonding for the magnetic separation and enrichment of ochratoxin A. The saturated adsorption of ochratoxin A by aptamer‐modified magnetic MIL‐101 was 7.9 times greater than that by magnetic metal‐organic framework MIL‐101 due to the former's high selective recognition as well as good stability. It could be used for extraction more than 12 times with no significant changes in the extraction efficiency. An aptamer‐modified magnetic MIL‐101‐based method of magnetic solid‐phase extraction combined with ultra high performance liquid chromatography with tandem mass spectrometry was developed for the determination of trace ochratoxin A with limit of detection of 0.067 ng/L. Ochratoxin A of 4.53–13.7 ng/kg was determined in corn and peanut samples. The recoveries were in the range 82.8–108% with a relative standard deviation (n = 5) of 4.5–6.5%. These results show that aptamer‐modified magnetic MIL‐101 exhibits selective and effective enrichment performance and have excellent potential for the analysis of ultra‐trace targets from complex matrices.     

Reconstruction of Block Copolymer Micelles to Long‐Range Ordered Dense Nanopatterns Via Light‐Tunable Hydrogen‐Bonding Association

Controlling the orientation and long‐range order of nanostructures is a key issue in the self‐assembly of block copolymer micelles. Herein, a versatile strategy is presented to transform one‐component oxime‐based block copolymer micelles into long‐range ordered dense nanopatterns. Photoisomerization provides a straightforward and versatile approach to convert the hydrogen‐bonding association from inward dimerization (E‐type oxime motifs, slightly desolvated in ethyl acetate) into outward interchain association (Z‐type ones, highly desolvated in ethyl acetate). This increases the glass transition temperature in bulk and converts swollen micelles into compact spherical micelles in solution. The reconstruction of these micelles on various substrates demonstrates that the phase transformation enables reconstruction of spherical micelles into mesoscopic sheets, nanorods, nanoworms, nanowires, networks, and eventually into long‐range ordered and densely packed textile‐like and lamellar nanopatterns on a macroscopic scale by adjusting E/Z‐oxime ratio and solvent‐evaporation rate.

     

Dispersive magnetic solid‐phase extraction of phthalate esters from water samples and human plasma based on a nanosorbent composed of MIL‐101(Cr) metal–organic framework and magnetite nanoparticles before their determination by GC–MS

In this study, a magnetic metal–organic framework was synthesized simply and utilized in the dispersive magnetic solid‐phase extraction of five phthalate esters followed by their determination by gas chromatography with mass spectrometry. First, MIL‐101(Cr) was prepared hydrothermally in water medium without using highly corrosive hydrofluoric acid, utilizing an autoclave oven heat supply. Afterward, Fe₃O₄ nanoparticles were decorated into the matrix of MIL‐101(Cr) to fabricate magnetic MIL‐101 nanocomposite. The nanocomposite was characterized by various techniques. The parameters affecting dispersive magnetic solid‐phase extraction efficiency were optimized and obtained as: a sorbent amount of 15 mg; a sorption time of 20 min; an elution time of 5 min; NaCl concentration, 10% w/v; type and volume of the eluent 1 mL n‐hexane/acetone (1:1 v/v). Under the optimum conditions detection limits and linear dynamic ranges were achieved in the range of 0.08–0.15 and 0.5–200 μg/L, respectively. The intra‐ and interday RSD% values were obtained in the range of 2.5–9.5 and 4.6–10.4, respectively. Ultimately, the applicability of the method was successfully confirmed by the extraction and determination of the model analytes in water samples, and human plasma in the range of microgram per liter and satisfactory results were obtained.     

Solubility Switching of Metallophthalocyanines and Their Larger Derivatives upon Encapsulation

Metallophthalocyanines (MPcs) are very useful pigments but scarcely soluble without appropriate functional groups in common solvents. Herein, we report that bent polyaromatic amphiphiles act as excellent solubilizing reagents for nonfunctionalized MPcs and larger MPc derivatives (e.g., CuPc, perhalogenated CuPcs, Cu‐naphthalocyanine, CuPc polymers, and double‐decker MPcs) in neutral water upon encapsulation. The resultant MPc nanocomposites display high stability towards heat and pH change. More importantly, the encapsulated MPcs can be released by simple protocols under mild conditions both into a bulk solvent and onto glass or polymer plates.     

A novel strategy for MALDI-TOF MS analysis of small molecules

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) does not work efficiently on small molecules (usually with molecular weight below 500 Da) because of the interference of matrix-related peaks in low m/z region. The previous methods developed for this problem focused on reducing the peaks caused by the traditional matrices. Here, we report a novel strategy to analyze small molecules in a high and interference-free mass range by using metal-phthalocyanines (MPcs) as matrices which should be capable of forming matrix-analyte adducts. The mass of the target analyte was calculated by subtracting the mass of MPc from the mass of the MPc-analyte adduct. MPcs were also detectable and could serve as internal standards. Various MPcs with aromatic or aliphatic groups and different metal centers were then synthesized and explored. Aluminum-phthalocyanines (AlPcs), gallium-phthalocyanines (GaPcs), and indium-phthalocyanines (InPcs) were efficient matrices to form MPc-analyte adducts in either the positive or negative ion mode. The detection limits varied from 17 to 75 fmol, depending on analyte types. The mechanism of adducts formation was also proposed. Collectively, our strategy provides a novel and efficient way to analyze small molecules by MALDI-TOF MS.     

Metallophthalocyanines Bearing Polymerizable {[5‐({(1E)‐[4‐(Diethylamino)phenyl]methylene}amino)‐ 1‐naphthy1]oxy} Groups as Electrochemical Pesticide Sensor

The synthesis and characterization of novel metallophthalocyanines (MPcs(ea)) carrying {[5‐({(1E)‐[4‐(diethylamino)phenyl]methylene}amino)‐1‐naphthyl]oxy} groups on four peripheral positions have been reported. These complexes have been characterized by a combination of FT‐IR, ¹H and ¹³C NMR, mass and UV‐Vis spectroscopy techniques. Redox active metal centers in the core of the Pc rings (Co (II) [CoPc(ea)], Mn(III) [Cl–MnPc(ea)], and Ti(IV)O [TiOPc(ea)]) and electropolymerizable substituents on the peripheral positions of Pc rings were used to increase redox activity and electrochemically polymerization ability of the complexes. The redox properties of MPcs(ea) were determined with voltammetry and in situ spectroelectrochemistry techniques. Then, GCE/MPc(ea) electrodes were constructed with the electropolymerization of MPcs and these electrodes were tested as the pesticide sensors. Sensing studies indicated that type of the metal center of the complexes effectively influenced the sensing activities. While all complexes showed interaction abilities for the fenitrothion, parathion and eserine, GCE/CoPc(ea) electrode detected the parathion selectively with LOD value of 4.52×10⁻⁷ mol dm⁻³ among studied three pesticides. Moreover, GCE/MnClPc(ea) electrode selectively detected eserine with LOD value of 6.43×10⁻⁷ mol dm⁻³ and GCE/TiOPc(ea) electrode detected parathion with LOD value of 8.64×10⁻⁷ mol dm⁻³. All GCE/MPcs(ea) electrodes showed high sensitivity and wide linear ranges for those pesticides. These sensing data illustrated the usability of these modified electrodes in real samples such as seawater with good selectivity and sensitivity.     

Thermo‐Responsive MOF/Polymer Composites for Temperature‐Mediated Water Capture and Release

We report an in situ polymerization strategy to incorporate a thermo‐responsive polymer, poly(N‐isopropylacrylamide) (PNIPAM), with controlled loadings into the cavity of a mesoporous metal–organic framework (MOF), MIL‐101(Cr). The resulting MOF/polymer composites exhibit an unprecedented temperature‐triggered water capture and release behavior originating from the thermo‐responsive phase transition of the PNIPAM component. This result sheds light on the development of stimuli‐responsive porous adsorbent materials for water capture and heat transfer applications under relatively mild operating conditions.     

Detection of S‐adenosylhomocysteine and methylation index in blood by capillary electrophoresis

This work proposes an approach to the direct analysis of S‐adenosylhomocysteine (SAH) and the methylation index in blood using CE with UV detection (CE‐UV). After application of meglumine postinjection, we achieved SAH in‐capillary preconcentration in the HClO₄ extracts of erythrocytes, which improved the detection limit (S/N = 3) of SAH up to 3 fmol or 180 nmol/L at the injection volume of 50 nL, taking into account the sample dilution rate. CE‐UV was carried out in 30 mM glycine and 45 mmol/L HCl (pH ～1.8) at 17 kV in a capillary 48 cm in length and 50 μm id. Accuracy of the technique was 101% and reproducibility was about 12%.     

Rapid screening and identification of antioxidants in the leaves of Malus hupehensis using off‐line two‐dimensional HPLC–UV–MS/MS coupled with a 1,1′‐diphenyl‐2‐picrylhydrazyl assay

The leaves of Malus hupehensis have a strong antioxidant activity and are commonly consumed as a healthy tea. However, detailed information about its antioxidants is incomplete. Herein, we developed an effective strategy based on combining off‐line two‐dimensional high‐performance liquid chromatography with ultraviolet and tandem mass spectrometry detection with a 1,1′‐diphenyl‐2‐picrylhydrazyl assay to rapidly screen and identify the antioxidants from the leaves of M. hupehensis. In the orthogonal two‐dimensional liquid chromatography system, a Venusil HILIC column was used for the first dimension, while a Universil XB‐C₁₈ column was installed in the second dimension. As a result, 32 antioxidants, including ten dihydrochalcones, two flavanones, nine flavonols, four flavones, and seven phenolic acids were tentatively identified, out of which 23 compounds, as far as we know, were isolated and characterized from the leaves of M. hupehensis for the first time. To the best of our knowledge, this is the first systematic investigation of the antioxidants from the leaves of M. hupehensis. The results indicated that the proposed method is an efficient technique to rapidly investigate antioxidants, especially for coeluted and minor compounds in a complex system.     

Preparative isolation and purification of 12 main antioxidants from the roots of Polygonum multiflorum Thunb. using high‐speed countercurrent chromatography and preparative HPLC guided by 1,1′‐diphenyl‐2‐picrylhydrazyl‐HPLC

A hyphenated strategy by off‐line coupling of 1,1′‐diphenyl‐2‐picrylhydrazyl‐high‐performance liquid chromatography, high‐speed countercurrent chromatography, and preparative high‐performance liquid chromatography was established to screen and separate antioxidants from ethyl acetate fraction of the roots of Polygonum multiflorum. Under the targeted guidance of 1,1′‐diphenyl‐2‐picrylhydrazyl‐high‐performance liquid chromatography experiment, 12 compounds were identified as potential antioxidants and readily isolated by high‐speed counter‐current chromatography and preparative high‐performance liquid chromatography. Ultraviolet spectroscopy, mass spectrometry, and ¹H NMR spectroscopy were employed to identify their structures, which were assigned as gallic acid ( 1 , 6.2 mg, 98.28%), catechin ( 2 , 8.8 mg, 90.69%), epicatechin ( 3 , 4.1 mg, 96.71%), polydatin ( 4 , 5.3 mg, 94.91%), 2,3,5,4′‐tetrahydroxy stilbene‐2‐Ο‐β‐D‐glucoside ( 5 , 20.2 mg, 95.23%), piceatannol ( 6 , 5.3 mg, 96.85%), rutin ( 7 , 5.4 mg, 97.92%), resveratrol ( 8 , 5.2 mg, 96.94%), isorhapontigenin ( 9 , 11.4 mg, 94.81%), hyperoside ( 10 , 9.7 mg, 98.52%), rhein ( 11 , 4.9 mg, 97.46%), and emodin ( 12 , 8.2 mg, 95.74%). Notably, compounds 6 and 9 were isolated from Polygonum multiflorum for the first time. In addition, antioxidant activity of compounds 1–12 were evaluated, and compounds 1–8 and 10 exhibited stronger antioxidant activity than ascorbic acid (positive control). These results indicated that the proposed method is a highly efficient strategy to screen and isolate antioxidants from complex natural products.     

Novel amorphous perfluorocopolymeric system: Copolymers of perfluoro‐2‐methylene‐1,3‐dioxolane derivatives

Perfluorotetrahydro‐2‐methylene‐furo[3,4‐d][1,3]dioxole (monomer I ) and perfluoro‐2‐methylene‐4‐methoxymethyl‐1,3‐dioxolane (monomer II ) are soluble in perfluorinated or partially fluorinated solvents and readily polymerize in solution or in bulk when initiated by a free‐radical initiator, perfluorodibenzoyl peroxide. The copolymerization parameters have been determined with in situ ¹⁹F NMR measurements. The copolymerization reactivity ratios are r _I = 1.80 and r _II = 0.80 in 1,1,2‐trichlorotrifluoroethane at 41 °C and r _I = 0.97 and r _II = 0.85 for the bulk polymerization. These data show that this copolymerization pair has a good copolymerization tendency and yields nearly ideal random copolymers. The copolymers have only one glass‐transition temperature from 101 to 168 °C, depending on the copolymer compositions. Melting endotherms have not been observed in their differential scanning calorimetry traces, and this indicates that all the copolymers with different compositions are completely amorphous. These copolymers are thermally stable (the initial decomposition temperatures are higher than 350 °C under an N₂ atmosphere) and have low refractive indices and high optical transparency from UV to near‐infrared. Copolymer films prepared by casting were flexible and tough. These properties make the copolymers ideal candidates as optical and electrical materials. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1613–1618, 2006     

Surfactant‐assisted electromembrane extraction combined with cyclodextrin‐modified capillary electrophoresis for the separation and quantification of Tranylcypromine enantiomers in biological samples

Surfactant‐assisted electromembrane extraction coupled with cyclodextrin‐modified capillary electrophoresis was developed for the separation and determination of Tranylcypromine enantiomers in biological samples. This combination would provide a new strategy for selective and sensitive determination of target analytes. The addition of surfactant in the donor solution improved the analyte transport into the lumen of hollow fiber that resulted in an enhancement in the analytes migration into acceptor solution. Optimization of the variables, affecting proposed method, was carried out and best results were achieved with a 175 V potential as driving force of the electromembrane extraction, 2‐nitrophenyloctylether as the supported liquid membrane, donor solution containing 0.2 mM Triton X‐100 with pH 3 and 0.1 M HCl for acceptor solution. Then, the extract was analyzed using cyclodextrin‐modified capillary electrophoresis method for separation of Tranylcypromine enantiomers. The best results were obtained with a phosphate running buffer (100 mM, pH 2.0) containing 7% w/v hydroxypropyl‐α‐cyclodextrin. Under the optimum conditions, a low limit of detection (3.03 ng/mL), good linearity (R² > 0.9953), and relative standard deviations below 4.0% (n = 5) were obtained. Finally, this procedure was applied to determine the concentration of Tranylcypromine enantiomers in urine samples with satisfactory results.     

Facile Synthesis of a Furan–Arylamine Hole‐Transporting Material for High‐Efficiency,Mesoscopic Perovskite Solar Cells

A novel hole‐transporting molecule (F101) based on a furan core has been synthesized by means of a short, high‐yielding route. When used as the hole‐transporting material (HTM) in mesoporous methylammonium lead halide perovskite solar cells (PSCs) it produced better device performance than the current state‐of‐the‐art HTM 2,2′,7,7′‐tetrakis‐(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD). The F101‐HTM‐based device exhibited both slightly higher J_sc (19.63 vs. 18.41 mA cm^?2) and V_oc (1.1 vs. 1.05 V) resulting in a marginally higher power conversion efficiency (PCE) (13.1 vs. 13 %). The steady‐state and time‐resolved photoluminescence show that F101 has significant charge extraction ability. The simple molecular structure, short synthesis route with high yield and better performance in devices makes F101 an excellent candidate for replacing the expensive spiro‐OMeTAD as HTM in PSCs.     

Encapsulation of a Porous Organic Cage into the Pores of a Metal–Organic Framework for Enhanced CO2 Separation

We present a facile approach to encapsulate functional porous organic cages (POCs) into a robust MOF by an incipient‐wetness impregnation method. Porous cucurbit[6]uril (CB6) cages with high CO₂ affinity were successfully encapsulated into the nanospace of Cr‐based MIL‐101 while retaining the crystal framework, morphology, and high stability of MIL‐101. The encapsulated CB6 amount is controllable. Importantly, as the CB6 molecule with intrinsic micropores is smaller than the inner mesopores of MIL‐101, more affinity sites for CO₂ are created in the resulting CB6@MIL‐101 composites, leading to enhanced CO₂ uptake capacity and CO₂/N₂, CO₂/CH₄ separation performance at low pressures. This POC@MOF encapsulation strategy provides a facile route to introduce functional POCs into stable MOFs for various potential applications.     

An efficient,green, and easy‐to‐scale‐up strategy for target‐oriented isolating cadinene sesquiterpenoids from Eupatorium adenophorum Spreng

A green and efficient strategy was established and optimized for target‐oriented extraction, enrichment and separation of cadinene sesquiterpenoids from Eupatorium adenophorum Spreng., using the combination of supercritical fluid extraction, molecular distillation, and industrial preparative chromatography for the first time. The extraction conditions of supercritical fluid extraction were initially optimized by orthogonal experimental design. Under the optimum conditions, the contents of 9‐oxo‐10,11‐dehydroageraphorone and 10Hβ‐9‐oxo‐ageraphorone, which were 55.00% and 6.01%, respectively, were much higher than conventional extraction methods. Then, the molecular distillation enrichment method was established and investigated by response surface methodology technology, which showed strong specificity for enriching target compounds and removing impurities from crude extracts. Under the optimum conditions of molecular distillation, total contents of cadinene sesquiterpenoids were increased to 89.19%. Finally, a total of 146 mg of 9‐oxo‐10,11‐dehydroageraphorone and 29 mg of 10Hβ‐9‐oxo‐ageraphorone were easily obtained by industrial preparative chromatography, from 200 mg of distillation fraction, with purities over 99%. The contents of target components were analyzed by HPLC, and structures of them were identified by high‐resolution MS, ¹H‐NMR, and ¹³C‐NMR spectroscopy. These results indicate that it is a simple, effective, and eco‐friendly strategy, which is easily converted into industrial scale.     

Determination of polychlorinated biphenyls by liquid chromatography–atmospheric pressure photoionization–mass spectrometry

This study presents the atmospheric pressure photoionization (APPI) of high‐chlorinated (five or more chlorine atoms) polychlorinated biphenyls (PCBs) using toluene as dopant, after liquid chromatographic separation. Mass spectra of PCB 101, 118, 138, 153, 180, 199, 206 and 209 were recorded by using liquid chromatography‐APPI‐tandem mass spectrometry (LC‐APPI‐MS/MS) in negative ion full scan mode. Intense peaks appeared at m/z that correspond to [M ? Cl + O]^? ions, where M is the analyte molecule. Furthermore, a detailed strategy, which includes designs of experiments, for the development and optimization of LC‐APPI‐MS/MS methods is described. Following this strategy, a sensitive and accurate method with low instrumental limits of detection, ranging from 0.29 pg for PCB 209 to 8.3 pg for PCB 101 on column, was developed. For the separation of the analytes, a Waters XSELECT HSS T3 (100 mm × 2.1 mm, 2.5 µm) column was used with methanol/water as elution system. This method was applied for the determination of the above PCBs in water samples (surface water, tap water and treated wastewater). For the extraction of PCBs from water samples, a simple liquid–liquid extraction with dichloromethane was used. Method limits of quantification, ranged from 4.8 ng l^?1, for PCB 199, to 9.4 ng l^?1, for PCB 180, and the recoveries ranged from 73%, for PCB 101, to 96%, for PCB 199. The estimated analytical figures were appropriate for trace analysis of high‐chlorinated PCBs in real samples. Copyright © 2014 John Wiley & Sons, Ltd.     

Comparisons of glyphosate adsorption properties of different functional Cr‐based metal–organic frameworks

A Cr‐based metal–organic framework, namely, MIL‐101(Cr), was modified with amino (NH₂–) and urea (UR₂–) groups, and the materials were evaluated as adsorbents for glyphosate, and a comparison with commercial activated carbon was also discussed. The effects of the adsorption factors, such as adsorbent concentration, adsorption time, pH and ionic strength were mainly investigated. The results showed that a pseudo‐second‐order rate equation described the adsorption kinetics mechanisms well, while the Langmuir model and the Freundlich model fitted different adsorption isotherms, respectively. Among the adsorbents we studied, NH₂‐MIL‐101(Cr) showed the maximum adsorbing capacity, which is 64.25 mg/g when pH = 3.0, while UR₂‐MIL‐101(Cr) did not reach the best adsorption performance due to the steric hindrance. The work opens up a new way for the modification of metal–organic frameworks for adsorption process.     

Yolk–shell microspheres assembled from Preyssler‐type NaP5W30O11014− polyoxometalate and MIL‐101(Cr) metal–organic framework: A new inorganic–organic nanohybrid for fast and selective removal of cationic organic dyes from aqueous media

Novel inorganic–organic yolk–shell microspheres based on Preyssler‐type NaP₅W₃₀O₁₁₀^14? polyoxometalate and MIL‐101(Cr) metal–organic framework (P₅W₃₀/MIL‐101(Cr)) were synthesized by reaction of K_12.5Na_1.5[NaP₅W₃₀O₁₁₀], Cr(NO₃)₃·9H₂O and terephthalic acid under hydrothermal conditions at 200°C for 24 h. The as‐prepared yolk–shell microspheres were fully characterized using various techniques. All analyses confirmed the incorporation of the Preyssler‐type NaP₅W₃₀O₁₁₀^14? polyoxometalate into the three‐dimensional porous MIL‐101(Cr) metal–organic framework. The results revealed that P₅W₃₀/MIL‐101(Cr) demonstrated rapid adsorption of cationic methylene blue (MB) and rhodamine B (RhB) with ultrahigh efficiency and capacity, as well as achieving rapid and highly selective adsorption of MB from MB/MO (MO = methyl orange), MB/RhB and MB/RhB/MO mixtures. The P₅W₃₀/MIL‐101(Cr) adsorbent not only exhibited a high adsorption capacity of 212 mg g^?1, but also could quickly remove 100% of MB from a dye solution of 50 mg l^?1 within 8 min. The effects of some key parameters such as adsorbent dosage, initial dye concentration and initial pH on dye adsorption were investigated in detail. The equilibrium adsorption data were better fitted by the Langmuir isotherm. The adsorption kinetics was well modelled using a pseudo‐second‐order model. Also, the inorganic–organic hybrid yolk–shell microspheres could be easily separated from the reaction system and reused up to four times without any change in structure or adsorption ability. The stability and robustness of the adsorbent were confirmed using various techniques.     

High breakdown strength and low loss binary polymer blends of poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) and poly(methyl methacrylate)

Dielectric materials with high breakdown strength and low loss are of crucial importance in capacitive energy storage electronics. Herein, a kind of polymer blend composed of poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) ferroelectric terpolymer and linear dielectric poly(methyl methacrylate) (PMMA) is presented. The polymer blend shows a breakdown strength of 733 MV/m and a charge‐discharge efficiency over 90% at 200 MV/m with optimized PMMA content, which are 101% and 28% higher than that of neat terpolymer. Moreover, microsecond discharge time of 2.26 μs, along with a power density that is 3.6 times that of the current commercially available biaxially oriented polypropylene, as well as great cyclic performance, has been achieved under an electric field of 200 MV/m. The findings of this research demonstrate that the incorporation of linear dielectric PMMA into poly(vinylidene fluoride)‐based ferroelectric polymer provides a new strategy in designing high breakdown strength low loss dielectric materials for reliable compact flexible film capacitors.     

Lithium‐Doped Silica‐Rich MIL‐101(Cr) for Enhanced Hydrogen Uptake

Metal‐organic frameworks (MOFs) show promising characteristics for hydrogen storage application. In this direction, modification of under‐utilized large pore cavities of MOFs has been extensively explored as a promising strategy to further enhance the hydrogen storage properties of MOFs. Here, we described a simple methodology to enhance the hydrogen uptake properties of RHA incorporated MIL‐101 (RHA‐MIL‐101, where RHA is rice husk ash—a waste material) by controlled doping of Li⁺ ions. The hydrogen gas uptake of Li‐doped RHA‐MIL‐101 is significantly higher (up to 72 %) compared to the undoped RHA‐MIL‐101, where the content of Li⁺ ions doping greatly influenced the hydrogen uptake properties. We attributed the observed enhancement in the hydrogen gas uptake of Li‐doped RHA‐MIL‐101 to the favorable Li⁺ ion‐to‐H₂ interactions and the cooperative effect of silanol bonds of silica‐rich rice‐husk ash incorporated in MIL‐101.