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An effective ternary organic-inorganic composite flame retardant of reduced graphene oxide-poly-dopamine@graphitic carbon nitride@10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide (RGO-PDA@g-C3N4@ODOPB) was successfully fabricated by co-precipitation method. Its property concerning the intrinsic flame retardancy and the mechanical performance was well studied when it was used as co-additives in combination with ammonium polyphosphate (APP) in epoxy resin (EP) samples. The surface morphology and the structure of RGO-PDA@g-C3N4@ODOPB were characterized by SEM, and the molecular structure and compositions were investigated by FT-IR, powder XRD and 1H NMR. TGA, limit oxygen index (LOI), vertical burning test (UL-94), cone calorimeter test, and SEM were also used to investigate the thermal properties and flame retardancy of materials. As expected, the flame retardancy of EP was significantly heightened after adding of RGO-PDA@g-C3N4@ODOPB composites. It showed that with the 20% adding of RGO-PDA@g-C3N4@ODOPB/APP into EP led to the decreasing of the peak heat release rate and the total heat release at 78% and 62.5%, respectively. Meanwhile, the LOI value of the EP composites was as high as 29% and reached UL-94 V-0 rate. It was deemed that the excellent flame retardancy was attributed to the forming of compact and stable carbon layer, which was being catalytic carbonization by APP existed in the RGO-PDA@g-C3N4@ODOPB/APP composites. At the same time, the non-combustible gas released from thermal cracking of g-C3N4 during the combustion also benefited the flame retardant performance of EP.

A novel photoactive porous material of GR/FeMIL-101 based on FeMIL-101 metal organic frameworks (MOFs) was successfully synthesized via a simple hydrothermal method. The structural and photoelectric properties of the GR/FeMIL-101 was analyzed by XRD, SEM, TEM, TGA, XPS, UV–vis DRS, FT-IR, PL and EIS methods. The photocatalytic performance for the selective oxidation of benzyl alcohol with GR/FeMIL-101 as catalysts was evaluated under visible light irradiation. The results showed that the GR/FeMIL-101 nanohybrid had better photocatalytic performance than both of FeMIL-101 and the pristine MIL-101. It was further found that the incorporation of Fe and MIL-101 caused valence fluctuations of Fe3+/Fe2+ which improved the absorption of visible-light and increased the separation efficiency of photogenerated charges. In addition, the combination of FeMIL-101 and GR could further promote the transfer rate of the photoelectrons. The mechanism of the reaction revealed that ·O2− was the dominating active specie in this reaction through active species trapping experiments. Fe doped MIL-101/GR nanohybrid was successfully synthesized as an efficient photocatalyst for selective oxidation of alcohols under visible-light and shown a best conversion of 50%. Analyses revealed that Fe was successfully doped into the MIL-101, valence fluctuation of Fe2+/Fe3+ not only improved the visible-light absorption but also increased the separation rate of photoexcited carriers. Graphene further improved the transportation rate of electron (e-). Subsequently, the possible photocatalytic mechanism for the selective oxidation of alcohols was proposed. It was proved that superoxide radicals (·O2-) was the main active species when the reaction was performed under Oxygen atmosphere.

The construction of excellently performing electrocatalysts for hydrogen evolution reaction (HER) with a low-cost and economical strategy is still struggling with an enormous challenge in electrochemical water splitting. In this work, a novel N-doped porous carbon substrate constructed heterojunction electrocatalyst (MoS2-MoP/NC) was fabricated by a simple and facile method. Based on the electronic interaction and synergistic effect between MoS2 and MoP phases, the fabricated MoS2-MoP/NC heterojunction catalyst exhibited excellent electrocatalytic ability. In addition, the N-doped porous carbon substrate had a good charge/mass-transfer ability, which could effectively facilitate electronic transmission or prevent the aggregation of MoS2-MoP nanosheets and improve the catalytic activity. The heterojunction catalyst significantly improved HER activity with a low overpotential of 83 and 103 mV at 10 mA cm−2 in a 1.0 M KOH and 0.5 M H2SO4 and Tafel slope of 59.38 and 59.20 mV dec−1 for HER, respectively. This work provides a simple, less expensive and efficient approach for constructing high-performance heterojunction catalysts for HER.

A new, simple, metal-free, and eco-friendly procedure has been proposed for the oxidation of alcohols with Oxone (potassium peroxymonosulfate) in water in the presence of six phase-transfer catalysts (PTC). Phase-transfer catalysts were found to display high catalytic activity in water solution. Furthermore, the oxidation of alcohols was also carried out with relatively good conversion and selectivity in water without any catalyst.

The introduction of defects can enhance the active sites on transition metal dichalcogenides, which can cause changes in crystal structures, and then lead to a change in the original catalytic performance. Herein, an efficient method of introducing defects was reported. In this method, high-energy iron ions were irradiated on the surface of Bi2Te3 nanosheets by ion irradiation technology, which resulted in the generation of a variety of defects. Compared to the original Bi2Te3 nanosheets, the Bi2Te3 nanosheets irradiated by iron ions showed significant improvement in the hydrogen evolution reaction performance in acidic solution. After the iron ion irradiation, the electric double layer capacitance of the Bi2Te3 nanosheets increased significantly, which indicated an increase in the number of active sites on the surface of Bi2Te3. Analysis of high-resolution transmission electron microscopy images reveals the occurrence of various defects on the surface of Bi2Te3 after the iron ion irradiation, which increased the active sites. Moreover, the conductivity of the iron ion-irradiated Bi2Te3 nanosheets was also significantly improved. It is noteworthy that iron ion irradiation changed the characteristic of the Bi2Te3 surface from hydrophobic to hydrophilic, which facilitated the release of hydrogen bubbles from the catalyst surface and exposed the active sites in time. At the same time, the damage caused by the large bubbles to the electrode material could be avoided, and the stability of the material was improved. This efficient iron ion irradiation method provides an innovative idea for the design of other high-efficient catalysts.

Doping has been widely recognized as an effective method for adjusting the performance of electrocatalysts. It can cause changes in the electronic structure of substances. Thereby, it can affect the intrinsic catalytic performance. Herein, we report a facile doping method in which phosphorus can be simultaneously doped into both CoTe2 and C. In the acidic solution, the hydrogen evolution reaction (HER) performance of the obtained P-CoTe2/C nanoparticles was significantly improved compared with that of undoped nanoparticles. At a current density of 10 mA cm-2, the overpotential decreased from 430 mV to 159 mV. Density functional theory (DFT) calculations show that phosphorus doping can produce new high activity Co-P catalytic sites. In addition, phosphorus can be doped into the carbon in the composite at the same time, which enhances the electrical conductivity of the composite. Moreover, in the process of calcination and doping, the electric double layer capacitance (Cdl) of the composite is significantly increased, which helps in exposing more active sites. This work has developed a multi-effect doping method that simultaneously increases the intrinsic activity, conductivity and active sites of the material. This method provides a new strategy for the performance regulation of other electrocatalysts.

Polydopamine/MIL-53(Fe) (PDA/MIL-53(Fe)) nanocomposite photocatalysts were synthesized with PDA (PDA = polydopamine) and MIL-53(Fe) using a nature-mimicking method. The structures, morphologies, optical properties and thermal stabilities of all the synthesized materials were characterized using a series of methods. In particular, the separation efficiency of photogenerated charge significantly increased after the incorporation of PDA into MIL-53(Fe), which resulted in an elevated photocatalytic activity of PDA/MIL-53(Fe) compared with the control groups. The PDA/MIL-53(Fe) nanocomposite could accelerate the conversion of primary or secondary alcohols into the corresponding aldehydes or ketones with a high specificity by direct hole-involving oxidation under visible-light irradiation and room temperature. The catalysts could be cycled at least three times without a significant decrease in the catalytic activity and this result showed the excellent recyclability and stability of the catalysts.

A simple and efficient procedure is reported for the oxidation of alcohols to carbonyl compounds with Oxone (potassium peroxymonosulfate) in the presence of tetrabutylammonium hydrogen sulfate as catalyst with excellent conversion and high selectivity using chloroform as solvent at room temperature. The efficiency of several phase-transfer catalysts in the oxidation of benzyl alcohols and benzydrol was studied. The proposed catalytic system was also evaluated in the oxidation of alcohols in water at room temperature.

Inspired by the mussel foot protein and chitosan-based macromolecular adhesives, a series of chitosan-graft-polypeptides were synthesized by ring-opening polymerization of three N-carboxyanhydrides (NCAs) - 3,4-dihydroxyphenylalanine-N-carboxyanhydride (DOPA-NCA), cysteine-NCA (Cys-NCA) and arginine-NCA (Arg-NCA) - using partial-NH2-protected chitosan as an initiator. These copolymers demonstrated good biodegradability and low cytotoxicity. The results of lap-shear adhesion test showed that the maximum lap-shear adhesion strength on the porcine skin and aluminum sheet were 195.97 ± 21.1 kPa and 3080 ± 320 kPa, respectively, and the maximum tensile adhesion strength on bone was 642.70 ± 61.1 kPa. The rat experiment in vivo showed that these copolymers exhibited good hemostatic performance and can promote the healing of skin wound and bone fracture. It is expected that thesecopolymeric adhesives will have broad applications in hemostasis and soft tissue adhesions.

To assess the mechanism and milder conditions for amines to imines, UiO-66-NH2 was chosen as an efficient photocatalyst for the transformation under light irradiation. A series of experiments for the catching of the active species were performed, and it was proved that holes (h+) and superoxide radicals ( O2−) were involved when the reaction was performed under air. The reaction also occurred because of the presence of nitrogen-centered radical cations and carbon-centered radicals, which were induced by photogenerated hole (h+) with considerable conversion and selectivity under anaerobic conditions. Our experiments revealed that the catalyst can be recycled for four times.

Carbon nanotube sieves (CNTs-S) with a flutelike shape were synthesized by cutting and perforating using a chemical oxidation etching method. Using the obtained CNTs-S as a hard template, SiO2-coated CNTs-S dual pore structures (CNTs-S@SiO2) were formed. Finally, tungstophosphoric acid was supported on CNTs, CNTs-S, and CNTs-S@SiO2 matrices by the incipient wetness method to obtain the corresponding supported catalysts PW12/CNTs, PW12/CNTs-S, and PW12/CNTs-S@SiO2. The results showed that obtained 30%PW12/CNTs-S and 30%PW12/CNTs-S@SiO2 catalysts in 30 wt% dipping solution had the best catalytic performance for Baeyer–Villiger oxidation of cyclic ketones by H2O2. The conversion of cyclohexanone was 94% and 91%, respectively, in 5 min under microwave irradiation. Cyclopentanone and adamantanone approached quantitative conversion and the selectivity of corresponding lactones reached 100%. The dual pore structure catalyst showed very excellent cyclic stability.

The introduction of defects can enhance the active sites on transition metal dichalcogenides, which can cause changes in crystal structures, and then lead to a change in the original catalytic performance. Herein, an efficient method of introducing defects was reported. In this method, high-energy iron ions were irradiated on the surface of Bi2Te3 nanosheets by ion irradiation technology, which resulted in the generation of a variety of defects. Compared to the original Bi2Te3 nanosheets, the Bi2Te3 nanosheets irradiated by iron ions showed significant improvement in the hydrogen evolution reaction performance in acidic solution. After the iron ion irradiation, the electric double layer capacitance of the Bi2Te3 nanosheets increased significantly, which indicated an increase in the number of active sites on the surface of Bi2Te3. Analysis of high-resolution transmission electron microscopy images reveals the occurrence of various defects on the surface of Bi2Te3 after the iron ion irradiation, which increased the active sites. Moreover, the conductivity of the iron ion-irradiated Bi2Te3 nanosheets was also significantly improved. It is noteworthy that iron ion irradiation changed the characteristic of the Bi2Te3 surface from hydrophobic to hydrophilic, which facilitated the release of hydrogen bubbles from the catalyst surface and exposed the active sites in time. At the same time, the damage caused by the large bubbles to the electrode material could be avoided, and the stability of the material was improved. This efficient iron ion irradiation method provides an innovative idea for the design of other high-efficient catalysts.

Doping has been widely recognized as an effective method for adjusting the performance of electrocatalysts. It can cause changes in the electronic structure of substances. Thereby, it can affect the intrinsic catalytic performance. Herein, we report a facile doping method in which phosphorus can be simultaneously doped into both CoTe2 and C. In the acidic solution, the hydrogen evolution reaction (HER) performance of the obtained P-CoTe2/C nanoparticles was significantly improved compared with that of undoped nanoparticles. At a current density of 10 mA cm-2, the overpotential decreased from 430 mV to 159 mV. Density functional theory (DFT) calculations show that phosphorus doping can produce new high activity Co-P catalytic sites. In addition, phosphorus can be doped into the carbon in the composite at the same time, which enhances the electrical conductivity of the composite. Moreover, in the process of calcination and doping, the electric double layer capacitance (Cdl) of the composite is significantly increased, which helps in exposing more active sites. This work has developed a multi-effect doping method that simultaneously increases the intrinsic activity, conductivity and active sites of the material. This method provides a new strategy for the performance regulation of other electrocatalysts.

In this study, inorganic magnesium hydroxide (MH) was modified by three phosphoric acids respectively to obtain three different novel functionalized monomers. The chemical structure and morphology of (Pn-MH) were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Further, functional monomers were introduced into the PET main chain structure. A new type of high-performance co-polyesters was successfully prepared. The specific structure of P1-MH-PET was characterized by 1H NMR spectroscopy. Thermal stability of Pn-MH-PETs was analyzed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The flame retardant properties were evaluated by limiting oxygen index (LOI), vertical combustion test (UL-94) and cone calorimeter. The results show that the thermal stability and flame retardant properties of 5%Pn-MH-PETs are greatly improved. Among them, the best performance is 5%P1-MH-PET, LOI is 32.5%, UL-94 test reached V-0 grade. Compared with neat PET, the peak heat release rate (PHRR), peak smoke release rate (PSPR), carbon dioxide release rate (CO2PR) and carbon monoxide release rate (COPR) decreased by 57.0%, 38.1%, 54.6% and 57.3%, respectively. Fortunately, the mechanical properties of 5%P3-MH-PET were also improved.

Chestnut shell (CS) acts as a multi-functional material in the one-step preparation of Fe3O4@C nanocomposite via hydrothermal method by using Fe(NO3)3 as Fe source without adding any other additive...

In this study, a novel organic-inorganic hybrid flame retardant 10-(1,4-dicarboxylic acid magnesium salt)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DMMH) was synthesized via neutralization and addition reaction of maleic acid, magnesium hydroxide and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), and subsequently used in an intrinsic flame retardant epoxy resin. The chemical structure and morphology of DMMH were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Further, the prepared DMMH was combined with ammonium polyphosphate (APP) to form an intumescent flame retardant system. The thermal stability and flame retardance were evaluated by thermogravimetric analysis (TG), UL-94 vertical burning test, limiting oxygen index (LOI) and cone calorimetry. It was observed that the addition of 1.7% DMMH and 5.3% APP led EP-7 to acquire UL-94 V-0 rating, with the limiting oxygen index of 26.0%. As compared with pure EP, the peak heat release rate, total heat release, smoke production rate and total smoke production of the sample was noted to decrease by 54.5%, 35.1%, 43.6% and 38.1%, respectively. In addition, the introduction of DMMH did not negatively impact the mechanical properties of the epoxy resin.