Activation Energy Of Dehydration Research Articles

Strong absorption of silica over full solar spectrum boosted by interfacial junctions and light–heat–storage of Mg(OH)2–(CrOx–SiO2)

Strong absorption of near-infrared (NIR) light is essential for efficient solar energy applications. NIR absorption primarily depends on the surface plasmon resonance of incident light with free charge carriers (FCCs). We demonstrated that S-scheme interfacial junctions (IJs) can substantially enhance FCC density, light-harvesting, photocurrent intensity, long lifetime of the charge carriers and photothermal effects, paving a way for novel light-material design. Abundant S–scheme IJs are constructed in CrOx–SiO2 nanoparticles, which increase the FCCs outstandingly and enhance light absorption exceptionally over the entire solar spectrum. IJs’ construction enables silica to harvest solar energy strongly. Doped with multifunctional CrOx–SiO2 nanoparticles, the photothermal-dehydration conversion and the stored heat of Mg(OH)2 can be improved by 7.0- and 5.1-times upon 30-min irradiation, respectively. The reversibility of the photothermal charge–discharge cycles of Mg(OH)2 improves 19.3 times. The thermal-storage kinetics is substantially improved owing to the reduction of the dehydration activation energy (−15.2 %). Mg(OH)2–CrOx–SiO2 composite is an excellent one-step system of light–heat–storage.

Fe/LiNO3/TiN co–modified MgO for enhanced thermochemical energy storage performance in MgO/Mg(OH)2 cycles

MgO/Mg(OH)2 thermochemical energy storage can convert solar energy and industrial waste heat into forms that are easier to store and transport by cyclic hydration/dehydration reactions. To achieve excellent energy storage performance, cyclic stability and optical absorption capability of MgO/Mg(OH)2, Fe/LiNO3/TiN co–modified MgO were synthesized for energy storage cycles by wet-mixing method. The energy storage performance, cyclic stability and dehydration kinetics of Fe/LiNO3/TiN co–modified MgO were studied in dual fixed–bed system and simultaneous thermal analyzer. The experimental results show that the Fe and LiNO3 in the composite not only increase the hydration conversion of MgO by 6.3 times at 30 min, but also reduce the dehydration temperature and dehydration activation energy of Mg(OH)2 by 99.4 °C and 64 %, respectively. TiN overcomes aggregation of MgO and sustains the excellent porous structure, which results in only a 9 % decrease in energy storage performance of Fe/LiNO3/TiN co–modified MgO after 15 energy storage cycles. Subsequently, TiN significantly strengthens the optical absorption performance of Mg(OH)2 and photothermal temperature under xenon-lamp simulated sunlight radiation. Furthermore, density functional theory calculation reveals that Fe and Li enhance the adsorption of H2O on MgO model and reduce energy barrier for hydration reactions by 62.76 %, while TiN effectively inhibits MgO clusters migration within the material and enhances the optical absorption coefficient. Hence, Fe/LiNO3/TiN co–modified MgO shows significant research value in MgO/Mg(OH)2 energy storage process.

Study on the Mechanism of Antioxidants Affecting the Spontaneous Combustion Oxidation of Coal.

In this paper, in order to further reveal the mechanism of oxidation inhibitors inhibiting coal spontaneous combustion, the mechanism of typical antioxidants butylated hydroxytoluene (BHT) and vitamin C (VC) inhibiting coal low-temperature oxidation was studied by thermogravimetry (TG), Fourier transform infrared spectroscopy, and quantum chemical simulation. This paper studies the thermal reaction process of coal by TG. The experimental results showed that the characteristic temperature of coal samples increased significantly after adding an antioxidant, and the maximum exothermic peak temperature of coal samples with BHT was 36 °C higher than that of raw coal, and the dehydration activation energy was 1.22 times higher than that of raw coal. Then, through the Fourier transform infrared spectroscopy experiment, it is concluded that antioxidants have a great influence on the content of active groups in the process of oxidative heating of coal, and the hydroxyl structure changes in coal are the most obvious. After BHT and VC were added to the coal, the hydroxyl content in the coal was reduced by 5.90 and 4.20%, respectively. Finally, the molecular models of antioxidants and oxygen-containing functional groups (RCOOH, R-CHO, and R-CH2-CH2-OH) in coal are constructed using quantum chemical theory, and their frontier orbitals and thermodynamic data are calculated according to density functional theory. The reaction mechanisms of antioxidants reacting with hydroxyl groups and with hydroxyl groups and oxygen-containing functional groups were comparatively analyzed. The results of orbital gap analysis indicated that antioxidants react more easily with hydroxyl groups than with oxygen-containing functional groups, and the order of their reaction activity is BHT > VC > R-CH2-CH2-OH > R-CHO > RCOOH. Compared to reactions containing oxygen-containing functional groups and hydroxyl groups, the thermodynamic reaction of hydroxyl groups and antioxidants is more active. Because antioxidants preferentially react with hydroxyl radicals and inhibit part of the chain cycle reaction during spontaneous combustion of coal, antioxidants play a good inhibitory role in spontaneous combustion of coal.

Experimental study on the oxidation kinetics of coal in typical coal mining areas of the Southern Junggar coalfield, Xinjiang, China

Coal spontaneous combustion (CSC) is a disaster associated with coal mining that leads to loss of coal resources and environmental and human health issues. To investigate kinetic characteristics for oxidation of coal, three coal samples were collected from different coal mining areas in the Southern Junggar coalfield. Subsequently, the collected coal samples were ground into different particle sizes and tested using microscopic and macroscopic methods, including thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, and temperature-programmed oxidation. The results obtained are as follows: the sharpest absorption peak (002) indicates that graphitization is high. Furthermore, the results show that the SKS coal sample is prone to spontaneous combustion; the greater the aromatic hydrocarbon content is, the more difficult it is for CSC to occur, while the opposite is true for oxygen-containing functional groups. The SKS data confirmed this conclusion; the rate for generation of CO and CO2 controlled the possibility of SKS oxidation at 110 °C and provided an indication of the temperature. During the dehydration stage, the WD sample had the lowest activation energy, indicating that it was most susceptible to spontaneous combustion. During the combustion stage, the lowest activation energy was found for the SKS sample with particle sizes < 0.075 mm, indicating that particle size was one of the factors affecting spontaneous combustion. The activation energy for dehydration was significantly lower than that for combustion, which showed that the coal oxygen reaction was more likely to occur in the dehydration stage. Based on DSC curves, the SKS sample had the largest exothermicity, indicating that it would ignite more readily.

Study on ZSM-5 catalytic pyrolysis mechanism of cellulose based on the Py-GC/MS and the density functional theory

In this study, Py-GC/MS and density functional theory (DFT) were used to analyze products and reaction mechanisms of cellulose undergone non-catalytic and catalytic pyrolysis by ZSM-5. The results showed that the main products of non-catalytic pyrolysis are furans, furfurals, aldehydes, ketones, carboxylic acids, esters and carbohydrate. While, in catalytic pyrolysis, the furan content decreased noticeably, and a new class of components (aromatic hydrocarbons) appeared. DFT studies exhibited that a hydrogen proton at acid sites of the catalyst was directly involved in most of the pyrolysis reactions of cellulose. Catalytic pyrolysis reduces the activation energy of dehydration and de-carbonylation by 40–70 kcal/mol and 86.05 kcal/mol, respectively, compared with non-catalytic pyrolysis.

Ionic liquid-assisted production of high-porosity biochar with more surface functional groups: Taking cellulose as attacking target

• Ionic liquid pretreating biomass produced high-porosity biochar at low temperature. • Ionic liquid modification enhanced the O-containing functional groups on biochar. • In pyrolysis ionic liquid attacked cellulose reducing its dehydration activation energy. • The recyclability of the used ionic liquid was high as 87.6% with less pollution. • Ionic liquid-modified biochar achieved higher Pb adsorption (99.4%) than control. Biochar has been widely used as a multifunctional environmental material, mainly attributing to its porous structure and O-containing functional groups. However, it is hard to simultaneously improve these two properties, because pyrolysis at high temperature (600–700 °C) usually causes loss of functional groups while low temperature (300–400 °C) is adverse to form porous structure. Ionic liquid (IL) is an organic solvent, which is regarded to have catalysis on biomass during pyrolysis. In this study, a representative IL, 1-butyl-2,3-dimethylimidazolium triflate was selected to co-pyrolysis with wastepaper, and a biochar with high-porosity and more functional groups was produced at low temperature (350 °C). With incorporation of IL, the wastepaper biochar’s surface area and pore volume were increased from 19.8 to 52.8 m 2 g −1 and from 0.033 to 0.174 cm 3 g −1 , respectively. Meanwhile, more O-containing functional groups were retained. In order to reveal the mechanisms, cellulose and lignin, as two model main compositions of wastepaper, were mixed with IL respectively to produce biochar. It was found that during thermal process, IL preferred to attack cellulose rather than lignin. Before 250 °C, IL induced cellulose cleaving to monosaccharides, including levoglucosan, furanoglucose and monocyclic furfural; between 250 °C and 300 °C, IL promoted monosaccharides dehydration by reducing dehydration activation energy, leading to a decrease of decomposition temperature. Adsorption experiments showed that this IL-modified biochar had a significantly higher Pb adsorbing capacity (99.4%) than the routine biochar (25.7%). This study provides a simple method to produce high-porosity biochar with more O-containing functional groups, which would maximize and broaden its environmental application.

Dehydration and Rehydration Mechanisms of Pharmaceutical Crystals: Classification Of Hydrates by Activation Energy

Dehydration strongly influences the stability of hydrate drug substances. Consequently, the ability to predict dehydration of crystalline hydrate using the intermolecular interactions of water molecules contained in the crystals is essential for drug development. The conventional method employed to predict the propensity for dehydration uses the dehydration temperature, which is related to how tightly water molecules are bound in the crystal lattice. However, it is difficult to predict the dehydration propensity of a particular hydrate using only the dehydration temperature because other kinetic factors affect dehydration behavior, such as intermolecular interactions, and drug-substance-to-water molar ratio in a hydrate. In this study, we explored the use of the dehydration activation energy Ea and rehydration behavior to classify 11 pharmaceutical hydrates into three classes according to their kinetic behavior related to the thermodynamic factors of hydrates. There is good agreement between these classes and hydrate crystal structures determined from single-crystal X-ray diffraction, and thus, the classification reflects their crystal structural features. We compared Ea to the dehydration temperatures for each class and found that Ea plays a crucial role and is better than the temperature for quantitative differentiation of the dehydration propensities in these hydrates.

Water sorption and heat storage in CaCl2 impregnated aluminium fumarate MOFs

Composite materials based on aluminium fumarate (AF) and CaCl2 have been developed for the storage of energy from renewable and waste sources. Composite Salt-Porous Matrix (CSPM) was synthesized by impregnating aluminium fumarate MOF host matrix with various relative CaCl2 salt contents (25–60 wt%). The resulting CSPMs were fully characterized by X-ray diffraction, N2 and H2O sorption isotherms at −196 and 25 °C, respectively, scanning electron microscopy and thermal analysis. The high surface area of the AF matrix (959 m2 g−1) drastically decreases upon the addition of salt, to about 50 m2 g−1. The heat storage performance of the composites was found to depend on the added amount of salt to the MOF matrix, with higher amounts of salt leading to better performance. The maximum water sorption capacity of 0.68 kgH2O kg−1, coupled with a high heat of water sorption (1840 kJ kg−1), makes these composites interesting when used at a rehydration level not exceeding CaCl2.4H2O to avoid any deliquescence and washing out of the salt. A kinetic study of the hydration demonstrated that salt deposition increases the water sorption rate in comparison with the host matrix. Moreover, the impact of salt deposition on the activation energy of dehydration of the host matrix was also determined by applying integral isoconversional methods.

Study on decomposition kinetics of activated alunite concentrate from copper tailings and leaching behavior of valuable elements

Alunite flotation concentrate extracted from copper tailings is considered to be a resource for recovery of potassium, aluminum and gallium, which mainly contains alunite, quartz, dickite and pyrite phases by the X-ray diffraction analysis. The calcination temperature and time affect not only the decomposition ratio of alunite but also the phase change of alumina. The effects of mechanical activation on thermal decomposition and leaching behavior of the alunite concentrate are investigated. The decomposition reactions of pyrite and alunite happen at 400–500 °C and 500–800 °C respectively, and the decomposition of alunite involves two stages, dehydration and desulphation. The mechanical activation produces some amorphisation and structural disordering, which is responsible for the decrease of apparent activation energy of dehydration as well as desulphation. The leaching ratio of potassium, aluminum and gallium increases with activation time.

Thermodynamic and kinetic studies on the polymorphic transformations of puerarin hydrates

Puerarin (PUE), a bioactive flavonoid from the plant Pueraria lobata, exists in two hydrated forms: monohydrate (PUEMH) and dihydrate (PUEDH). The aim of the present work was to explore the thermodynamic and kinetic mechanism of the polymorphic transformation of PUE, including the solvent-mediated polymorphic transformation (SMPT) of PUEMH to PUEDH and the solid-state polymorphic transformations (SSPTs) of PUEMH and PUEDH. PUEMH and PUEDH were identified as isolated and channel hydrate, respectively. The thermodynamic parameters (ΔG < 0, ΔH < 0, and ΔS < 0) indicated that the SMPT was a spontaneous, exothermic and entropy-decreased reaction. The facilitating roles of stirring rate and temperature on the SMPT were favored by the primary and secondary nucleation process of PUEDH. In addition, the results of SSPTs suggested that PUEMH and PUEDH would transform to two different anhydrates (PUEAH-I and PUEAH-II) upon heating, respectively. The dehydration rate of PUEMH was slower than that of PUEDH due to the stronger hydrogen bond interactions. The rate-limiting step for the dehydration of PUEMH was the diffusion of water molecules, resulting in the increased dehydration activation during the dehydration process, while the dehydration activation energy of PUEDH showed opposite trend due to the complicated crystallization process of PUEAH-II.

Interfacial polarization triggered by glutamate accelerates dehydration of hydrated zinc ions for zinc-ion batteries

The huge activation energy barrier during the dehydration of hydrated zinc ions ([Zn(H2O)6]2+ → 6H2O + Zn2+) of aqueous zinc-ion batteries (ZIBs) has limited their capacity and hindered their development. Here, we report a novel and efficient method for accelerating the dehydration of hydrated zinc ions through interfacial polarization triggered by glutamate. Using MoS2 as a research model, the specific capacity of the MoS2 adsorbed by glutamate (Glu-MoS2) increased from 72 mAh g−1 to 182 mAh g−1, which is 2.5 times the original specific capacity. Different from changing the structure of materials, surface treatment also can significantly improve performance. In addition, there is a reversible phase conversion from the 2H phase to the 1 T phase during the charging and discharging process of Glu-MoS2, which plays an important role in optimizing the performance. The interfacial polarization caused by glutamate to reduce the activation energy of dehydration provides a new strategy to increase the capacity of ZIBs.

Effects of microwaves on the dehydration characteristics of santite

In this paper, by using the microwave irradiation, the dehydration curves of santite (KB5O8·4H2O) were obtained and modeled. By using a different mathematical model, the kinetic parameters of the dehydration process were determined. The dehydration of santite was completed at 180, 105 and 60 min for 360, 600 and 800 W, respectively. The characterization techniques of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy were applied to the obtained santite mineral and dehydrated santite mineral. From the obtained XRD analysis, santite, its powder diffraction file number is 01-072-1688 transformed into an amorphous phase after the microwave dehydration process. From the FT-IR and Raman analyses, it can be said that partial dehydration was achieved due to the disappearance of structural H2O bands but remaining some hydroxyl bands. For the modeling results, Verma model best fits the experimental data obtained from the dehydration and the dehydration activation energy was calculated as 11.92 kW × g–1.

Some Thermodynamic Properties of White Yam (Dioscorea rotundata) Slices Dehydrated in a Refractance WindowTM Dryer

The objective of this study is to estimate the changes in Enthalpy, Entropy and Gibbs Free Energy of yam slices dehydrated at different temperatures using a Refractance WindowTM dryer. Dehydration of 1.5, 3.0 and 4.5 mm thick yam slices, was performed with water temperatures of 65, 75, 85 and 95oC in the flume of a Refractance WindowTM dryer. During the dehydration operations, the moisture-content history data were recorded. For the process conditions considered, the moisture content history data was used to calculate the moisture diffusivity and the activation energy of dehydration of the samples. Subsequently, changes in Enthalpy, , Entropy, , and Gibbs Free Energy, ), were calculated. For the process conditions studied, the changes in, , , and, varied from 20,381.33 to 25,217.05 J.mol-1., -140.69 to -122.29 J.mol-1.K-1.and 67,934.80 to 70,220.15 J.mol-1, respectively. This study is essential as knowledge of these thermodynamic parameters are useful for the optimal design and sizing of preservation dryers for argo-products. Keywords— Enthalpy; Entropy; Gibbs Free Energy; Refractance WindowTM Dryer; Yam

Moisture Diffusivity and Activation Energy Estimation of White Yam (Dioscorea rotundata) Slices Using Drying Data from a Refractance WindowTM Dryer

The objective of this study was to estimate the moisture diffusivity of different sizes of white yam slices at different temperatures using a Refractance WindowTM dryer. To achieve this objective, dehydration of 1.5, 3.0 and 4.5 mm thick yam slices was performed with water temperatures of 65, 75, 85 and 95 oC in the flume of a Refractance WindowTM dryer. Variation of moisture content with dehydration time data were obtained during the dehydration operations. The activation energies of dehydration for different sizes of yam slices were estimated for the temperatures considered. For the process conditions studied, the effective moisture diffusivities varied from 5.35 x 10-08 to 1.45 x 10-07 m2/s. The effective moisture diffusivity, Deff, at a specified temperature was observed to increase with increasing yam slice size. The effective moisture diffusivity, Deff, at a specified yam slice size is observed to increase with increasing dehydrating temperature. The activation energy, Ea, for the yam slices, ranged from 23.21 to 28.30 (kJ/mol) and it was observed to increase with increasing thickness of the yam slices. The activation energy values estimated were within the range observed for other equipment. This study is important in that, the moisture diffusivities and activation energy parameters estimated will be useful in the design, modelling, and optimization of such dryers. Keywords: Yams; Moisture Diffusivity; Activation Energy; Refractance WindowTM Dryer

Effect of LiOH Addition on Dehydration Reaction of Mg(OH)&lt;sub&gt;2&lt;/sub&gt;

The dehydration behavior of LiOH-modified Mg(OH)2 (LiOH/Mg(OH)2), as a new chemical heat storage material, was investigated. Structural analysis of LiOH/Mg(OH)2 was carried out using an X-ray diffraction (XRD) meter. The profile of the dehydration reaction of LiOH/Mg(OH)2 was observed to analyze the dehydration kinetics of the LiOH/Mg(OH)2 samples. The XRD patterns of the LiOH/Mg(OH)2 samples shifted toward higher angles than that of Mg(OH)2. This indicated that the lattice parameter might have changed and lattice defects such as oxygen vacancies might have been generated on the surface of Mg(OH)2. The rate of the dehydration reaction increased as the amount of added LiOH increased; therefore, LiOH/Mg(OH)2 could be a potential chemical heat storage material. We concluded that LO20 (Mg(OH)2 containing 20 mol% LiOH) was the combination with the most optical mixing mole ratio. This result was determined by analyzing the dehydration activation energy values. When the dehydration reactions of the LiOH/Mg(OH)2 samples were considered to be first-order reactions, the calculated mole fraction of Mg(OH)2 could not be reproduced. However, the calculated mole fractions of Mg(OH)2 were in agreement with those measured considering the reactions to be zero- and first-order reactions. Therefore, the kinetics of the dehydration reaction of the LiOH/Mg(OH)2 samples included both zero- and first-order reactions.

Ab-initio and experimental study of pentose sugar dehydration mechanism in the gas phase

In this work pentose sugar (D-xylose, D-ribose and D-arabinose) gas phase dehydration reaction was investigated by means of mass spectrometric techniques and theoretical calculations. The ionic species derived from the dehydration reaction of protonated D-ribose and D-arabinose were structurally characterized by their fragmentation patterns and the relative dehydration energies measured by energy resolved CAD mass spectra. The results were compared with those recently obtained for D-xylose in the same mass spectrometric experimental conditions. Dehydration of C1-OH protonated sugars was theoretically investigated at the CCSD(T)/cc-pVTZ//M11/6-311++G(2d,2p) level of theory. Protonated pentoses are not stable and promptly lose a water molecule giving rise to the dehydrated ions at m/z 133. D-xylose, D-ribose and D-arabinose dehydration follows a common reaction pathway with ionic intermediates and transition states characterized by similar structures. Slightly different dehydration energies were experimentally measured and the relative trend was theoretically confirmed. The overall dehydration activation energy follows the order arabinose < ribose < xylose. Gas-phase pentose sugar dehydration leads to the formation of protonated 2-furaldehyde as final product. Based on the experimental and theoretical evidence a new mechanistic hypothesis starting from C1-OH protonation was proposed.

Structure and Stability of Racemic and Enantiopure Pimobendan Monohydrates: On the Phenomenon of Unusually High Stability

Study of structures and physicochemical properties of racemic (rac-H) and enantiopure (enant-H) hydrates of the active pharmaceutical ingredient pimobendan revealed that both hydrates have highly similar crystal structures and exhibit unusually high stability. Both structures contain identical two-dimensional layers and very similar conformations. The most significant difference is the stacking of these layers. The high stability of both hydrates appeared as extremely low solubility over a wide temperature range as well as an exceptionally high dehydration temperature and melting point. Study of the dehydration process showed that both hydrates have different activation energies of dehydration and kinetic model. Intermolecular interaction energy calculations showed that the dispersion interactions provide a highly significant stabilizing force in both pimobendan hydrates, while their exceptionally high stability can be associated with an efficient interplay between the hydrogen bonding and the dispersion ...

In‐situ isothermal micro‐Raman spectroscopy reveals the activation energy of dehydration in α‐FeOOH

A real‐time, isothermal micro‐Raman spectroscopy was developed as a single technique for monitoring the solid state kinetics of dehydration and measuring its activation energy. The technique comprises of acquisition and numerical analysis of a set of isothermal time‐dependent Raman spectra. α‐FeOOH transformation to Fe2O3 in N2 atmosphere was continuously monitored for up to 16 h at three temperatures. Dehydration activation energy of 1.4(1) eV was estimated. The Raman band evolution of two modes with different symmetries (B1g ~ 240 cm−1 and Ag ~ 400 cm−1) and the intensity decay of B1g mode at ~540 cm−1 are analyzed independently utilizing kinetic model‐free approach. The study opens new possibilities for developing versatile solid state chemical and bio‐chemical Raman sensors and advances the field of analytical micro‐Raman spectroscopy. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Synthesis of belite cement from nano-silica extracted from two rice husk ashes

Nano-silicas extracted from a pure rice husk ash calcined in the laboratory (RHA) and ash from an impure industrial rice husk waste (BRHA), were used to form belite cement by firing with two different calcium sources (calcium carbonate and calcium nitrate). The nano-silica extracted from RHA was highly reactive due to its high pore volume and low activation energy of dehydration. The formation of belite cement from both nano-silicas was studied by firing with two different calcium sources, Ca(NO3)2 and CaCO3 at 800–1100 °C. Both nano-silicas formed the principal phase in belite cement (larnite or β-C2S) at temperatures as low as 800 °C, especially with calcium nitrate as the calcium source. Thus, highly impure BRHA is shown to be very suitable as a starting material for the low-temperature production of belite cement, especially in conjunction with calcium nitrate as the calcium source.

Aqueous Grafting Ionic Liquid on Graphene Oxide for CO2 Cycloaddition

In this study, a facile and environment-friendly approach was developed to immobilize water-soluble imidazolium- and pyridinium-based ionic liquids (ILs), i.e. [SmIm]X (X = Cl and I) and [SPy]I, on graphene oxide (GO) sheets in aqueous medium by controlling the grafting temperature. Several characterizations including OEA, FT-IR and XPS techniques have been applied to investigate the effects of the grafting temperature on the preparation for GO-ILs in aqueous medium. As-prepared composites were employed as heterogeneous catalysts for CO2 cycloaddition. Results showed that the amount of [SmIm]I on GO sheets reached a high level (about 1.7 mmol/g GO) under the mild temperature (i.e. 40–60 °C), owing to the inhibition of the self-condensations among ILs molecules in water under the mild temperature. The resulting composites exhibited excellent catalytic activity to CO2 cycloaddition, affording the maximum conversion of propylene oxide (PO) as about 93% in 4 h, much higher than that on [SmIm]I. It could be explained that the abundant hydrogen bonding donor (hydroxyl groups) on GO sheets assisted in the ring opening of PO, which promoted the reaction. These heterogeneous catalysts could be reused for at least five runs without significant loss in activity, implying the stable and reusable capability of as-prepared catalysts. The aqueous grafting mechanism was proposed here, which went through a two-step reaction. ILs with silane coupling agent are firstly hydrolyzed to silanol in water, and grafting reaction then happens by removing H2O molecules under the mild temperature due to the low activation energy for dehydration. It differs greatly from the traditional grafting mechanism in organic solvents, which involves the direct dealcoholization under the high temperature because of the high activation energy for the reaction. Water-soluble [SmIm]I were efficiently grafted on GO sheets in water under the mild temperature (30–60 °C); while the predominant self-condesation happened among [SmIm]I molecules under the high temperature (beyond 60 °C) in comparison.