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Fat grafting is an efficient and safe procedure for the correction of upper eyelid sulcus deepening. Stromal vascular fraction (SVF) gel has been proven to be an ideal fat derivative and can be widely used for facial augmentation. We aimed to determine the efficacy of SVF gel for the correction of a mild-to-moderate sunken superior sulcus among Asian patients.Patients with a mild-to-moderate sunken superior sulcus underwent SVF gel grafting of the sunken upper periorbital area. The primary result was the quantitative volume difference in the superior sulcus region before and after grafting. This was evaluated through three-dimensional VECTRAThirty-one patients with mild-to-moderate sunken upper eyelids were included in this study. The average unilateral injected amount was 1.235 mL (± 0.171 mL). The 1-year delta volume was 0.801 ± 0.086 mL, and the effective survival volume was 65.3% (± 6.1%). The median preoperative pretarsal space and upper lid area ratio was 1.010 (± 0.150). The median postoperative pretarsal space and upper lid area ratio at 1 year was 0.159 (± 0.031) (n = 62; P 0.0001), indicating a significantly reduced sunken appearance. The average GAIS score was 2.174 (± 0.391). All patients were satisfied with their surgical outcomes. The reoperation rate was 12.9%.SVF gel is safe and effective for the treatment of a mild-to-moderate sunken superior sulcus and is associated with satisfactory clinical outcomes and short recovery times.

Atractylodes macrocephala Koidz. (AM), an herb of traditional Chinese medicine, is well-known for anti-oxidant, anti-tumor and immune regulation potential. However, it is low bioactive compound content that restricts the application of this species. Elicitation is considered as an effective method to enhance biomass and bioactive compound in plants. Our precious study found that polysaccharide of Chrysanthemun indicum L. could promote plant growth by triggering plant defense. In the present study, polysaccharide of Chrysanthemun indicum L. is used to stimulate the accumulation of biomass and bioactive compound with different concentration in Atractylodes macrocephala Koidz. during pot, plot and field experiments. The results suggested that polysaccharide of Chrysanthemun indicum L. could significantly enhance the accumulation of biomass, atractylenolides and polysacchrides. Moreover, 2 mg/mL is determined and verified to be the appropriate concentration during field experiments. In addition, RT-qPCR revealed that CIP-induced terpenoid synthesis in AM mainly depended on mevalonate (MVA) pathway. This is the first report on the discovery of polysaccharide of Chrysanthemun indicum L. for the enhanced accumulation of biaomass and bioactive compound and the use of its for agricultural production.

Highly dispersed molybdenum trioxide were loaded in three-dimensional dendritic mesoporous silica nanospheres (MoO3@3D-DMSNs) by one-pot method. The mesoporous silica nanospheres with central radical channels were obtained through the interaction of bisurfactant and molybdenum source and the as-synthesized MoO3@3D-DMSNs were characterized by specific tests. As a result, the as-prepared MoO3@3D-DMSNs exhibited better catalytic performance for epoxidation of olefins. When the molar ratio value of Mo and Si is 5%, the specific surface area (SBET = 185.8 m2/g) and pore volume (Vp = 0.46 cm3/g) of MoO3@3D-DMSNs reach a maximum, and the catalytic activity is the best for the epoxidation of cyclooctene. The conversion could reach 84% with a selectivity above 98% after 6 h. The better catalytic performance can be maintained after five reaction-regeneration cycles. The dendritic mesoporous structure can be well preserved after recycling. Additionally, olefins with electron-absorbing group exhibit better catalytic activity with MoO3@3D-DMSNs-5 as catalyst. Hence, MoO3@3D-DMSNs catalysts with the center-radial oriented channel exhibit good activity and stability. The central radial channel can effectively disperse the active center MoO3 and play a key role in the transmission and accessibility of substrates, and it would have a good application prospect in the catalytic reactions.

In order to develop functional energy storage device, it is necessary to improve the energy and power density. As a potential candidate that can synergistically harmonize energy and power density, lithium ion capacitor (LIC) has shown exciting promises in recent years. However, in the recent years, alternative metal has been explored to replace lithium in such metal-ion capacitor system. Hence, in this work we present zinc ion capacitor (ZIC) in which zinc acts as negative electrode and Metal Organic framework (MOF) derived carbon as positive electrode. The assembled ZIC was able to demonstrate exceptional power density of 85.5 kW kg-1 and a maximal energy density of 36.4 W h kg-1, together with 99 % capacitance retention after cycling for 20 000 cycles.

Hypertrophic scar (HS) is a fibroproliferative disorder that causes cosmetic as well as functional problems; however, to our knowledge, there is no satisfactory treatment for HS to date. Previous studies have indicated that angiogenesis plays a crucial role in HS formation; therefore, anti-angiogenetic therapies are considered effective in improving HS. Although tacrolimus (TAC) has been proven effective in preventing HS formation in vivo and in vitro, its underlying mechanism remains controversial and ambiguous. Because of its anti-angiogenic effects in other diseases, we aimed to determine whether TAC reduces HS by suppressing angiogenesis. Using a rabbit ear HS model that we developed, HS was treated once a week with normal saline, dimethyl sulfoxide, or TAC for 3 weeks. Histological evaluation indicated that TAC significantly reduced collagen deposition and microvessel density in scar tissues. Moreover, immunofluorescence staining for CD31 and vascular endothelial growth factor (VEGF)-A revealed that TAC significantly inhibited HS angiogenesis. In vitro analysis showed that TAC inhibited endothelial cell migration and tubulogenesis as well as the viability and proliferation of human umbilical vascular endothelial cells (HUVECs) and HS fibroblasts (HSFBs). Furthermore, TAC significantly downregulated the expression of the human angiogenetic factors VEGF-A, FGF-2, PDGF-β, and TGF-β1 in HUVECs and HSFBs. Additionally, TAC-mediated inhibition of angiogenesis decreased the gene expression of crucial fibrotic markers, including α- smooth muscle actin and collagens 1 and 3, in HSFBs. This is the first study to demonstrate the inhibitory effects of TAC on HS formation mediated by a mechanism involving the suppression of scar angiogenesis.

A facile post-synthetic strategy was developed to functionalize the preformed hollow mesoporous silica spheres by encapsulating the molybdenum dioxide (MoO2) nanoparticles inside the interior cavity. Hollow mesoporous silica spheres were prepared and employed as carriers, and the encapsulation of MoO2 nanoparticles was achieved through a one-pot hydrothermal protocol. After characterization, the encapsulated MoO2 nanoparticles were certified to be ultrafine and highly dispersed, which greatly promoted the catalytic activity. The as-prepared catalysts were utilized in epoxidation of alkenes and exhibited as a promising catalyst in this reaction. After reacting for 10 h, the optimal catalyst MoO2@SiO2-1 achieved a conversion above 95% and selectivity above 95%, respectively. Moreover, the catalysts also exhibited good reusability, conversion of 78% and selectivity of 89% (reaction time 4 h) were still obtained after recycling for 5 times. Meanwhile, the employed facial and efficient hydrothermal approach could be expanded to other molybdenum modified heterogeneous catalysts in various applications. Keywords: Post-synthesis, Ultrafine, Molybdenum dioxide, Alkene, Epoxidation

Porous C

Introduction Although several surgical methods have been introduced to treat mild-to-moderate blepharoptosis, including levator-based techniques such as Müller muscle–conjunctival resection, few complications and better functional and aesthetic outcomes remain elusive for plastic surgeons. Hence, this study aimed to provide a new technique (bridge technique) using the levator aponeurosis–Müller’s muscle flap to achieve optimal blepharoptosis correction for function and aesthetics among Asians. Methods From January 2019 to May 2020, this new technique was performed on 157 consecutive patients with mild-to-moderate blepharoptosis. Our technique was based on the anchor of the levator complex to the tarsus using mattress stitches and three-layer fixation, which provided a reliable motion transmitter for elevating the upper eyelid. The patients’ medical records and photographs were reviewed 12 months postoperatively to assess the margin reflex distance 1 (MRD1), incidence of complications, and aesthetic outcomes. Results The average preoperative and postoperative MRD1 measured 1.2 ± 0.31 mm and 3.7 ± 0.34 mm, respectively. A significant difference was observed between the preoperative and postoperative distance values (p

Functionalization of vegetable oils (VOs) including edible, non-edible, and waste cooking oil (WCOs) to epoxides (EVOs) is receiving great attention by many researchers from academia and industry because they are renewable, versatile, sustainable, non-toxic, and eco-friendly, and they can partially or totally replace harmful phthalate plasticizers. The epoxidation of VOs on an industrial scale has already been developed by the homogeneous catalytic system using peracids. Due to the drawbacks of this method, other systems including acidic ion exchange resins, polyoxometalates, and enzymes are becoming alternative catalysts for the epoxidation reaction. We have reviewed all these catalytic systems including their benefits and drawbacks, reaction mechanisms, intensification of each system in different ways as well as the physicochemical properties of VOs and EVOs and new findings in recent years. Finally, the current methods including titrimetric methods as well as ATR-FTIR and 1H NMR for determination of conversion, epoxidation, and selectivity of epoxidized vegetable oils (EVOs) are also briefly described.

Hydrogel adhesives are attractive for applications in intelligent soft materials and tissue engineering, but conventional hydrogels usually have poor adhesion. In this study, we designed a strategy to synthesize a novel adhesive with a thin hydrogel adhesive layer integrated on a tough substrate hydrogel. The adhesive layer with positive charges of ammonium groups on the polymer backbones strongly bonds to a wide range of nonporous materials’ surfaces. The substrate layer with a dual hydrogen bond system consists of (i) weak hydrogen bonds between N,N-dimethyl acrylamide (DMAA) and acrylic acid (AAc) units and (ii) strong multiple hydrogen bonds between 2-ureido-4[1H]-pyrimidinone (UPy) units. The dual hydrogen-bond network endowed the hydrogel adhesives with unique mechanical properties, e.g., toughness, highly stretchability, and insensitivity to notches. The hydrogel adhesion to four types of materials like glass, 316L stainless steel, aluminum, Al2O3 ceramic, and two biological tissues including pig skin and pig kidney was investigated. The hydrogel bonds strongly to dry solid surfaces and wet tissue, which is promising for biomedical applications.

Polymeric carbon nitride (C3N4) is currently the most potential nonmetallic photocatalyst, but it suffers from low catalytic activity due to rapid electron–hole recombination behavior and low specific surface area. The morphology control of C3N4 is one of the effective methods used to achieve higher photocatalytic performance. Here, bulk, lamellar and coralloid C3N4 were synthesized using different chemical methods. The as-prepared coralloid C3N4 has a higher specific surface area (123.7 m2 · g−1) than bulk (5.4 m2 · g−1) and lamellar C3N4 (2.8 m2 · g−1), thus exhibiting a 3.15- and 2.59-fold higher photocatalytic efficiency for the selective oxidation of benzyl alcohol than bulk and lamellar C3N4, respectively. Optical characterizations of the photocatalysts suggest that coralloid C3N4 can effectively capture electrons and accelerate carrier separation, which is caused by the presence of more nitrogen vacancies. Furthermore, it is demonstrated that superoxide radicals (·O2 −) and holes (h+) play major roles in the photocatalytic selective oxidation of benzyl alcohol using C3N4 as a photocatalyst.

Porous C3N4 (PCN) is favored by researchers because it has more surface active sites, higher specific surface area and stronger light absorption ability than traditional g–C3N4. In this study, cerium dioxide nanoparticles (CeO2–NPs) with mixed valence state of Ce3+ and Ce4+ were doped into the PCN framework by a two-step method. The results indicate that CeO2–NPs are highly dispersed in the PCN framework, which leads to a narrower band gap, a wider range of the light response and an improved the separation efficiency of photogenerated charge in PCN. Moreover, the specific surface area (145.69 m2 g−1) of CeO2–NPs doped PCN is a 25.5% enhancement than that of PCN (116.13 m2 g−1). In the experiment of photocatalytic selective oxidation of benzyl alcohol, CeO2–NPs doped porous C3N4 exhibits excellent photocatalytic activity, especially Ce–PCN–30. The conversion rate of benzyl alcohol reaches 74.9% using Ce–PCN−30 as photocatalyst by 8 h of illumination, which is 25.7% higher than that of pure porous C3N4. Additionally, CeO2–NPs doped porous C3N4 also exhibits better photocatalytic efficiency for other aromatic alcohols.

Background Double eyelid blepharoplasty is the most popular cosmetic surgery among Asian populations. Although various surgical procedures have been reported, certain complications still arise, including asymmetry or the disappearance of the double eyelid crease, an unnatural double eyelid crease curve, and distinct scars. Objectives The aim of this study was to describe a new blepharoplasty technique intended to reduce the various complications and create dynamic, natural-looking double eyelids. Methods From September 2018 to June 2019, the new technique was performed on 92 Chinese patients. The core of our technique was to construct a reliable motion transmitter, the orbital septum-levator aponeurosis flap, which was sutured to the tarsus. The outcomes were assessed 6 months after the surgery by reviewing medical records and photographs to assess the aesthetic outcomes, the relapse rate, and the incidence of complications. Results In the aesthetic outcome assessment, 86 patients were graded as good and 4 were graded as fair; of the latter, 2 had uneven scars and 2 showed showed a slight asymmetry of the double eyelid curve in length or width. Two patients were graded as poor because of the disappearance of the double eyelid crease. The relapse rate was 2.2%. Two patients had temporary hematoma. Six patients had lagophthalmos that subsided within 30 days. No cases of infection or ptosis were observed. Conclusions The bridge technique is an effective method for creating dynamic, natural-looking double eyelids. However, the long-term outcome of this new surgical approach requires further study. Level of Evidence: 4

A general thermal decomposition strategy is reported to fabricate MoO3@SiO2 nanoreactors, with a mesoporous silica shell and embedded MoO3 nanoparticles. The novel preparation procedure involves mixing certain mass ratio of (NH4)6Mo7O24·4H2O (AMM) and hollow mesoporous silica spheres (HMSS) by grinding, fusion and thermal decomposition of (NH4)6Mo7O24·4H2O under calcination and removing the residual via filtration. The as-prepared MoO3@SiO2 nanoreactors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), N2 adsorption/desorption and X-ray photoelectron spectra (XPS). The nanoreactors were utilized in epoxidation of alkenes and displayed high catalytic activity and stability. The mass ratio of AMM and HMSS greatly affected the properties and catalytic performance of the nanoreactors. The optimal mass ratio of AMM: HMSS has been confirmed as 1/2. After reacting for 12 h with H2O2 (50 wt%) as oxidant, conversion and selectivity of optimal MoO3@SiO2-400-1/2 almost reached up to 98% and 99%, respectively. Furthermore, the catalyst still had high conversion (78%) and selectivity (95%) at 4 h epoxidation of cyclooctene after recycling for 6 runs. Kinetics study was also carried out and demonstrated the epoxidation of alkenes follows the first order model.

A novel Schiff (Mo) base complex supported on GO surface was successfully prepared, which was further combined with graphitic carbon nitride (g-C3N4) polymer (Mo-GO/g-C3N4) to make it photo-active. The photocatalytic activity of the resulting nano-composite was tested under simulated sunlight (AM 1.5) for the epoxidation of various olefin substrates. In addition, surface photovoltage (SPV) measurements were applied to explore the electron acceleration effect caused by GO and molybdenum. It was demonstrated that both GO and the metal active centers can efficiently accelerate electron transfer, which would finally contribute to the superior catalytic performance.

In this study, the flower-like Bi2WO6 with oxygen vacancies were synthesized by using the anionic and cationic dual surfactants strategy. The study results indicate that the synergistic effect of dual surfactants provides more oxygen vacancies for Bi2WO6, which leads to a narrower band gap, an expanded light response range, and an improved separation efficiency of photogenerated charges in Bi2WO6. In the experiment of photocatalytic selective oxidation benzyl alcohol, Bi2WO6 with dual surfactants shows excellent photocatalytic activity. Especially when the molar rate of CTAB to SDS is 2, the conversion of benzyl alcohol overs 90%, which is 1.74-fold than that of pure Bi2WO6. Meanwhile, Bi2WO6 with dual surfactants also exhibits better photocatalytic efficiency for other aromatic alcohols. Furthermore, the free radical capture experiments show that superoxide radical (•O2−) and hole (h+) play a major role in the photocatalytic selective oxidation of benzyl alcohol.

Highly dispersed Molybdenum (VI) incorporated hollow mesoporous silica catalyst was facilely synthesized with a selective etching strategy and then followed with a modified immersion method. Firstly, hollow mesoporous silica spheres were obtained from solid silica spheres with the interaction of cetyltrimethyl ammonium bromide (CTAB) and Na 2 CO 3 . Then the catalytic sites were loaded by modified and direct immersion methods as comparison. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption/desorption and X-ray photoelectron spectra (XPS). The reactivity of the catalysts was also detected under the same condition in olefin epoxidation. Compared with these two immersion methods, modified method exhibited the best turnover number of 3873 at 6 h with a better reactivity and textural properties than direct one. Highly dispersed molybdenum indeed brought excellent activity and high stability. The conversion could reach 100% with a selectivity above 99% after 12 h. And the catalyst still had a conversion above 86% and a selectivity above 93% after five runs. More importantly, this modified immersion method could also be widely used in the preparation of catalysts as a simple but efficient way.

A lamellar porous Mo-modified carbon nitride polymers (CN-Mo) was successfully prepared by a simple bottom-up method, which involves molecule self-assembly by hydrogen bonding between uracil and melamine. Analysis Results of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS) show that Mo element has been doped in the skeleton of carbon nitride. The optical characterization results of the as-prepared photocatalysts show that, CN-Mo has a suitable band structure that can promote the separation of carriers and expands the absorption of light. Compared with CN, CN-Mo has better photocatalytic activity for epoxidation of olefins. When the mass value (relative to melamine) of ammonium molybdate tetrahydrate is 2 %, the photocatalytic efficiency is the best for the epoxidation of styrene. And the conversion rate of styrene reaches 38.4 % and the selectivity of styrene oxide is up to 83.2 %. In addition, it can maintain the better photocatalytic performance for the epoxidation of styrene after five reaction-regeneration cycles. This finding provides an effective development direction for photocatalytic olefins epoxidation under mild conditions.

Nowadays, the most commonly used cold-resistant plasticizer, bis(2-ethylhexyl)adipate (DOA), not only has the poor migration resistance so that it can only be used as auxiliary plasticizer, but also causes huge pollution to the environment, especially water. Here, using renewable and green oleic acid as raw material, we had synthesized a series of oleate plasticizers. By means of capability tests, we detected that the Ti (initial degradation temperature) of PVC films plasticized with oleate plasticizers was 40 °C higher than that of DOA/PVC and 20 °C higher than that of DOTP/PVC. More importantly, in addition to illustrious migration resistance, they could maintain remarkable flexibility in cold environments as well. The low-temperature efficiency value of these oleate plasticizers exceeded 70 °C, which was much higher than DOTP and DOA. These results demonstrated that they possessed the potential to replace toxic DOP and poorly stable DOA, which provided an effective and green approach to solve the harm of plastic products to human health and the threat to the environment. In addition, these plasticizers broadened the application of PVC in cold environments, which was a boon for the application of PVC industry in the cold-resistant field, and contributed to sustainability of the hackneyed and oft-maligned PVC industry.

The efficient catalysts were designed to allow the entry and release of reactants and products into the mesoporous SBA-15 in which the active sites, peroxophosphotungstate, were entrapped by silylation with three different silylating agents (C3, C5, and C8 arm). The as-prepared catalysts were characterized by elemental analysis, ICP analysis, TGA, XRD, N2 adsorption/desorption, SEM, TEM, and FT-IR spectra. Their catalytic performances were tested for the epoxidation of soybean oil using different parameters such as temperature, H2O2 to unsaturation molar ratio, catalyst loading and stirring speed. The resulting epoxidized soybean oil was analyzed qualitatively and quantitatively by FT-IR and 1HNMR. The results confirmed that the catalyst silylated with C8 arm is promising for the synthesis of epoxides of long-chain carbon and reusable at least three times without obvious decrease in activity. Moreover, use of H2O2 oxidant and free of solvent in the epoxidation reaction are the main advantages of these catalysts.

Auxin is an essential regulator in various aspects of organism growth and development. Members of the Aux/IAA family of genes encode short-lived nuclear proteins and mediate the responses of auxin-regulated gene expression. Here, the first identification and characterization of 22 cDNAs encoding the open reading frame of the Aux/IAA family in Chinese hickory (named as CcIAA) has been performed. The proteins encoded by these genes contain four whole or partially conserved domains of the Aux/IAA family. Phylogenetic analysis indicated that CcIAAs were unevenly distributed among eight different subgroups. The spatio-specific expression profiles showed that most of the CcIAAs preferentially expressed in specific tissues. Three CcIAA genes, including CcIAA11, CcIAA27a2 and CcIAAx, were predominantly expressed in stem. The predominant expression of CcIAA genes in stems might play important roles in vascular reconnection during the graft process. Furthermore, expression profiles of Aux/IAA genes during the grafting process of Chinese hickory have been analysed. Our data suggested that 19 CcIAAs were down-regulated and 3 CcIAAs (including CcIAA28, CcIAA8a and CcIAA27b) were induced, indicating their specializations during the grafting process. The involvement of CcIAA genes at the early stage after grafting gives us an opportunity to understand the role of auxin signalling in the grafting process.

Molybdenum(VI) Schiff base complexes modified mesoporous SBA-15 hybrid heterogeneous catalysts were synthesized by the reaction of MoO2(acac)2 with mesoporous SBA-15 functionalized by grafting procedures of 3-aminopropyl-triethoxysilane and salicylaldehyde, respectively. The physico-chemical properties of the as-synthesized catalysts were analyzed by ICP-AES, XRD, N2 adsorption–desorption, FT-IR, SEM, TEM and EDX. The as-synthesized catalysts were effective in the catalytic epoxidation of cyclohexene. The catalytic activity can be further enhanced by silylation of the residual Si–OH groups using Me3SiCl, which was largely due to the higher content of Mo active sites. The conversion and selectivity reached to 97.78 and 93.99 % using tert-butyl hydroperoxide as oxidant for Mo–CH3–SA–NH2–SBA-15, while 81.97 and 89.41 % in conversion and selectivity for Mo–SA–NH2–SBA-15. At the same time, the catalytic performances of the hybrid materials were further systematically investigated under various reaction conditions (solvent, oxidants and alkenes, etc.). Mo–CH3–SA–NH2–SBA-15 catalyst can be recycled effectively and reused four cycles with little loss in activity. In addition, the results from hot filtration demonstrated that the catalytic activity mostly resulted from the heterogeneous catalytic process.

Two novel molybdenum(VI) tridentate Schiff base complexes supported onto modified mesoporous SBA-15 were prepared by a covalent grafting method, one of which involved the postsynthesis trimethylsilylation of Mo-FSAP-Cl-SBA-15 to remove the residual surface silanol groups. The prepared complex materials were characterized by FT-IR, XRD, SEM, TEM, 29Si CP–MAS-NMR, TGA, ICP-AES and nitrogen adsorption–desorption. Both two were active in the catalytic epoxidation of cyclohexene at 80 °C using tert-butylhydroperoxide (TBHP) as oxidant and 1,2-dichloroethane as solvent. The catalytic activity of the heterogenized organo catalyst can be further enhanced by silylation of the residual Si–OH groups using Me3SiCl, due to the higher content of Mo active sites and better surface hydrophobicity. As a result, using the more efficient catalyst Mo-FSAP-CH3-Cl-SBA-15 for catalytic reaction, the conversion and selectivity were 94.38% and 91.63%, respectively, under the optimized condition. After being used five times, the conversion and selectivity of Mo-FSAP-CH3-Cl-SBA-15 were still above 80.00% and 90.00% indicating the good reusability of Mo-FSAP-CH3-Cl-SBA-15.

Considering the issue of low yield in the synthesis of benzoate esters and fatty acid alkyl esters, designing a high catalytic activity composite catalyst is very significant and attractive. In this study, the rational design strategy was used to develop a novel poly(p-styrenesulfonate acid, namely PSSF) grafted multi-walled carbon nanotube composite with graphene oxide nanomaterial (PSSF-mCNTs-GO) using a simple two-step method. FT-IR and Raman spectroscopy, XRD, SEM, TEM, and NH3-TPD were used to characterize the inorganic–organic hybrid material. In particular, the addition of GO remarkably enhanced its catalytic performance in the production of fatty acid alkyl esters (92.16%) and benzoate esters (90.27%), in which the conversion was more than doubled as a result of its strong π–π interaction with the substrate. In addition, PSSF-mCNTs-GO can be separated from the substrate conveniently and still maintained a relatively high catalytic activity even after 6 times recycling, which indicates its rather good reusability. This novel catalyst is promising in the synthesis of biodiesel and benzoate esters.

Epoxides are important industrial intermediates applied in a variety of industrial processes. During the production of epoxides, catalysts have played an irreplaceable and unique role. In this review, the historic progress of molybdenum-based catalysts in alkene epoxidation are covered and an outlook on future challenge discussed. Efficient catalysts are demonstrated including soluble molybdenum complexes, polyoxometalates catalysts, molybdenum-containing metal organic frameworks, silica supported molybdenum-based catalysts, polymer supported molybdenum-based catalysts, magnetic molybdenum-based catalysts, hierarchical molybdenum-based catalysts, graphene-based molybdenum containing catalysts, photocatalyzed epoxidation catalysts, and some other systems. The effects of different solvents and oxidants are discussed and the mechanisms of epoxidation are summarized. The challenges and perspectives to further enhance the catalytic performances in alkenes epoxidation are presented.

A novel mesoporous MoO2 composite supported on graphene oxide (m-MoO2/GO) has been designed and applied as an efficient epoxidation catalyst. The m-MoO2/GO composite was characterised by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmet–Teller surface area analysis, field emission scanning electron microscopy, and transmission electron microscopy. Compared with pure mesoporous MoO2 (m-MoO2) and amorphous MoO2-graphene oxide (a-MoO2/GO), m-MoO2/GO exhibits the best catalytic activity. The conversion and selectivity for cyclooctene are both over 99 % in 6 h. Remarkably, the mesoporous structure in m-MoO2/GO which derives from SiO2 nanospheres endows the catalyst better catalytic performance for long chain olefins: the conversion of methyl oleate can be as high as 82 %. Such a robust catalyst can be easily recycled and reused five times without significant loss of catalytic activity. This novel catalyst is promising in the synthesis of epoxides with a long carbon chain or large ring size.

An organic–inorganic catalyst was prepared by the reaction of p-salicylidine aminobenzoic acid with mesoporous silica modified with 3-chloropropyl groups. The hydrolysis and co-condensation of tetraethylorthosilicate (TEOS) and 3-chloropropyltrimethoxysilane (CPTES) took place during the preparation process. MoO2(acac)2 was then introduced into the mesoporous silica functionalized with a Schiff base ligand. The structural properties of the prepared catalysts were investigated by a series of techniques, such as elemental analysis, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption curves, and thermogravimetric analysis (TGA). The results demonstrated that the MoVI Schiff base complex was successfully tethered on the silica support, and the hexagonally ordered mesoporous structure of the SBA-15-type silica was well retained after the anchoring reaction. The heterogeneous catalyst showed good catalytic activities in the liquid-phase epoxidation of olefins with t-BuOOH as the oxygen source in 1,2-dichloroethane solvent at 80°C. Several important factors, including oxidant-to-substrate ratio, solvent, and catalyst reusability, were investigated. Under the optimum reaction conditions, using this heterogeneous catalyst for the cyclohexene epoxidation reaction, a high conversion of 97.20 % and selectivity of >99 % was achieved after 4 h, while the catalytic activity nearly remained unchanged over four runs.