Publications by authors named "Zhengqiu Yuan"

Article Synopsis
  • - The researchers created a material called defective carbon nitride (DCN-) using a two-step process involving nitric acid treatment and high-temperature calcination, which made the material porous and increased its surface area compared to pure carbon nitride (CN).
  • - As a result of these enhancements, DCN- showed much better visible light absorption and lower electron-hole recombination, leading to significantly improved photocatalytic hydrogen production, with the best sample (DCN-600) being 55.9 times more efficient than pure CN.
  • - The study also discovered that specific structural elements within carbon nitride, particularly tri-s-triazine (heptazine) configurations, play a crucial role in optimizing the material's band gap,
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A novel BiS-zinc oxide/cellulose acetate composite film was prepared through a blending-wet phase conversion and in situ precipitate method. The results revealed that the incorporation of BiS in the film increased the cavity density and uniformity, which provided additional space for the growth of active species and improved the interaction between dye pollutants and active sites. Zinc oxide acted as a mediator to facilitate the separation of electron-hole pairs effectively preventing their recombination, thus reducing the photo-corrosion of BiS.

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In this study, hydrophobic polymer composite films based on polyurethane (PU) were prepared for oil-water separation. Hydrophilic fumed silica (nano-SiO) was introduced as reinforcing filler, and silane coupling agent (KH550) was used to crosslink PU with nano-SiO in situ for enhancing the nano-SiO dispersion in the films. The microscopic morphology, crystalline structure, and hydrophobic properties of the films were characterized by using scanning electron microscopy, X-ray diffraction, FTIR spectroscopy, water contact angle, and water absorption tests.

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Two-phase Ca-doped LaVO:Eu nanocrystals were prepared through a hydrothermal method with the help of SOD CITR and EDTA surfactants. The phase and morphology of the products were characterized by XRD and TEM, and the fluorescence performances were also recorded. The results indicated that Ca ions were doped into the LaVO:Eu host lattice, impeding the aggregation of the nanocrystals and enhancing the luminescence intensity.

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In this work, various photocatalysts were synthesized with an impregnation-precipitation process to in situ decorate Ag-based nanoparticles (NPs, including AgPO, AgCl, AgO, and AgCO) on the cellulosic paper. The structure and properties of the Ag-based composites were characterized by scanning electron microscopy, X-ray diffraction, transmitting electron microscopy, UV-vis diffuse reflectance spectra, and photocatalysis testing. The results showed that cellulosic paper is an efficient carrier which is feasible to grasp NPs due to the cellulosic nanofiber-network microstructure.

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In order to separate palladium (II) from electroplating wastewaters, poly(4-vinylpyridine)-b-polysulfone-b-poly(4-vinylpyridine) (P4VP-PSF-P4VP) / polysulfone blend membranes were fabricated by combining non-solvent induced phase separation, surface segregation and self-assembly of block copolymer. Amphiphilic P4VP-PSF-P4VP was used as the membrane base material, which was synthesized by introducing the functional monomer of 4-vinylpyridine (4-VP), and polysulfone as the additive. Effects of blend ratio and 4-VP content on membrane performance, such as structure, hydrophilicity, pure water flux and adsorption capacity towards Pd (II), were investigated.

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Article Synopsis
  • A series of composite separation membranes made from polyurethane hydrogel and thermoplastic elastomer were created using a wet phase inversion method.
  • The membranes displayed an irregular porous structure, and tests showed alterations in their chemical and physical properties, particularly when thermoplastic elastomer was added.
  • The study found that the membranes' swelling ratios and water flux varied with the presence of functional groups, while glycine permeation was influenced significantly by external temperature and pH levels.
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Bacterial cellulose (BC) is a new kind of cellulose with great potential in enhancing preparation of isotactic Polypropylene (iPP) composites, which have been found with excellent performance. However, the interface compatibility between BC and iPP is poor. In this study, iPP/BC composites were prepared by solution mixing.

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Isotactic polypropylene (iPP) is a commonly used thermoplastic polymer with many excellent properties. But high brittleness, especially at low temperatures, limits the use of iPP. The presence of transcrystallization of iPP makes it possible for fiber-reinforced iPP composites with higher strength.

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Durability is critically important in energy storage applications. Based on the model of the contagious degradation of a chemically active surface (CDCAS), a general model for durability has been systematically built. In practical lithium-ion batteries (LIBs), gassing swelling, limited by slow electrochemical processes, occurs over years of use and causes the LIB cell to rupture at an unpredictable moment.

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Structure has a significant effect on the lignin degradation, so the investigation of structural effect on the lignin depolymerization is important and imperative. In this study, hydrogenolysis of three typical lignins with different structures, dealkaline lignin, sodium lignosulfonate and organosolv lignin, was intensively compared over the synergistic catalyst of CrCl3 and Pd/C. The effects of reaction temperature, time, hydrogen pressure and catalyst dosage on the catalytic performance of lignin species were investigated.

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An efficient lignin depolymerization process with highly controllable product distribution was presented using metal chloride (MClx) cooperated with Pd/C. The catalytic performances of MClx were investigated. The effect of reaction conditions on the lignin depolymerization and products distribution were also studied.

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