JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2022
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IF 6.76
Junfeng Yang,Yuyang Wu,Yanhui Dong,Hao Cui,Chenyang Shi,Hang Sun,Shengyan Yin
Herein, a ternary Bi@H-TiO 2 /B-C 3 N 4 type II heterostructure is successfully designed and prepared via metal Bi as cocatalyst for photocatalytic H 2 generation. As expected, under λ > 300 nm light, the highest photocatalytic hydrogen production rate (HPR) of Bi@H-TiO 2 /B-C 3 N 4 is up to 223.08 μmol g −1 h −1 . Excitingly, under visible light (λ > 400 nm), the highest HPR of Bi@H-TiO 2 /B-C 3 N 4 is increased to 18.84 μmol g −1 h −1 , which is about 67.3 times, 37.7 times and 6.8 times as high as that of H-TiO 2 , B-C 3 N 4 and H-TiO 2 /B-C 3 N 4 under the same conditions, respectively. Moreover, the electrochemical impedance spectroscopy and transient photocurrent tests manifest that the interface resistance of Bi@H-TiO 2 /B-C 3 N 4 composite decreases and the photocurrent density increases after loading metal Bi. These results indicate that loading metal Bi as cocatalyst (providing more electron trapping sites) is beneficial to improve photocatalytic activity in the type II heterostructure composite. And the electron transfer directions (B-C 3 N 4 → H-TiO 2 → Bi or B-C 3 N 4 → Bi) are proved by ultraviolet photoelectron spectroscopy test. Therefore, the Bi@H-TiO 2 /B-C 3 N 4 photocatalyst with strong visible light absorption is expected to be a promising candidate in photocatalytic fields under visible light.
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ACS Applied Materials & Interfaces
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2022
·
IF 10.383
Zhenzhong Li,Huating Jiang,Jinxiu Liu,Tiantian Ning,Nam T. S. Phan,Fang Zhang
Conformational dynamics of active sites in enzymes enable great control over the catalytic process. Herein, we constructed a metal–organic framework with conformationally dynamic active sites (Rh2-ZIF-8). The active sites in Rh2-ZIF-8 were composed of the imidazolate-bridged bimetallic center with a catalytic dirhodium moiety and structural zinc site. Even though the coordination sphere of the dirhodium species was saturated with two circularly arranged esp groups and two axial 2-MeIm ligands, it could still effectively catalyze the direct synthesis of N–H aziridines from olefins with high activity. We found that such a self-adaptive catalytic process was based on the dynamic breakage and reformation of the rhodium–zinc imidazolate bridges. Interestingly, the in situ generated dirhodium site with a unique Rh2(esp)2(2-MeIm)1 configuration was able to exhibit obviously enhanced selectivity compared to homogeneous catalyst Rh2(esp)2. Furthermore, the surrounding zinc imidazolate groups could effectively protect the dirhodium moieties from harsh environments, and this ultimately endowed it with high stability.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
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IF 7.139
Kexin Liu,Shilong Yang,Yi Chen,Wenlei Zhang,Pu Liu,Xiucheng Zheng
The hydrolysis of ammonia borane (NH 3 BH 3 , AB) is an efficient strategy for high-purify hydrogen evolution . However, it is indispensable to develop a suitable catalyst because this reaction is kinetically infeasible at room temperature . In this work, we prepared a series of nano hexagonal boron nitride (h-BN) supported CuNi bimetallic catalysts through a facile adsorption-chemical reduction procedure. The effects of various molar ratios of Cu to Ni and CuNi loadings on AB hydrolysis were investigated in details. Benefitting from the proper porous structure , the interesting alloy effect of Cu and Ni, as well as the synergistic effect between h-BN and CuNi, 20 wt% Cu 0.5 Ni 0.5 /h-BN displays the highest catalytic activity among the as-prepared catalysts. Apart from satisfactory durability, the corresponding hydrogen generation rate, turnover frequency at 303 K in base solution and apparent activation energy are 2437.0 mL g −1 min −1 , 6.33 min −1 and 23.02 kJ mol −1 , respectively, which are very outstanding compared with many previous results. Our work not only provides a proper non-precious metal catalyst for hydrogen generation from the hydrolysis of chemical hydrogen storage materials but also offers a facile strategy for synthesizing metallic functional materials .
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PROGRESS IN ORGANIC COATINGS
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2022
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IF 6.206
Cheng Li,Xiao Wang,Meng Zhang,Yue Sun,Yexiang Cui,Yanji Zhu,Huaiyuan Wang
Inert inorganic anti-corrosion fillers enjoy the advantages of stable performance, but most of them face the problems of poor compatibility and disability. Therefore, strategies about addressing the above problems need to be developed. Herein, based on interface enhancement strategy, one typical inert inorganic filler h-BN was armed with fluoro-substituted polyaniline (PFAN). To this end, diazotization reaction was utilized to introduce aniline group to h-BN, and emulsion polymerization was employed to grow the micro-size copolymer of aniline and 2-fluoroaniline. Benefitting from the above interface enhancement attempt, the compatibility of h-BN with resin was enhanced, which was explained by the chemical armed PFAN participated in the curing process of epoxy. Moreover, the disability of h-BN was also improved owed to this interface armor. Therefore, combining the fully developed barrier properties of h-BN with passivate ability of PFAN, the coating containing a small addition amount (0.9 wt%) of the composite fillers to epoxy coatings significantly improved their long-term corrosion resistance , which was confirmed by the EIS result that its low frequency impedance value was maintained above 10 10 and was about 10 3 times larger than that of pure EP coating after being immersed in 3.5 wt% NaCl solution for 120 days.
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Journal of Composites Science
·
2021
·Vol. 5
·期 8
·207
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IF 0
Ying Zhou,Cuihuan Song,Zhixiang Chen,Qixin Zhou
In this study, we prepared a novel coating composed of hexagonal molybdenum oxide (h-MoO3) nanofiller and waterborne epoxy resin (WEP) to provide corrosion protection. We optimized the h-MoO3nanorod synthesis methodology first by changing different parameters (pH, temperature, etc.). Furthermore, the as-prepared h-MoO3rods were characterized using a scanning electron microscope (SEM) and X-ray diffraction (XRD). Finally, the electrochemical impedance spectroscopy (EIS) test results verified that the anticorrosive performance of the composite coatings was improved by incorporation of low content of MoO3nanofiller (0.5 wt.%) compared to pure WEP sample. This developed composite will provide a new insight for the design and fabrication of one-dimensional (1D) nanomaterial (e.g., nanorod) reinforced epoxy coating and other polymeric coating processes.Keywords:waterborne epoxy;molybdenum trioxide nanorod;composites
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ChemCatChem
·
2021
·Vol. 13
·期 14
·3312-3318
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IF 5.686
Ding Ding,Bing Yan,Yang Wang,An-Hui Lu
Graphical Nanofiber Catalysis : Hexagonal boron nitride has been regarded as a potential inorganic nonmetallic catalyst for the oxidative dehydrogenation of propane. Herein, a novel nanofiber catalyst consisting of hexagonal boron nitride/silica oxide ( h -BN/SiO 2 ) was prepared via electrospinning method, which exhibited remarkable 24.9 g olefins ⋅ g BN −1 ⋅ h −1 productivity of olefins in oxidative dehydrogenation of propane. Fibrous nanomaterials have drawn considerable attention in the field of catalysis due to the promoted utilization of the surface and facilitated mass transfer process. In this study, we prepared one-dimensional nanofiber catalysts consisting of hexagonal boron nitride/silica oxide ( h -BN/SiO 2 ) via electrospinning method. The key is to prepare uniform sols consisting of exfoliated h -BN. The diameters of the nanofiber catalysts can be tuned in the range of 150–300 nm through h -BN loading change. When used in oxidative dehydrogenation of propane (ODHP), the obtained nanofibrous catalysts exhibited a 12.4 % conversion of propane and 85.1 % selectivity towards propylene, with remarkable olefins productivity of 24.9 g olefins ⋅ g BN −1 ⋅ h −1 , which is more than 5 times higher than that of bulk ODHP catalysts reported to date. This study shines light on the specific one-dimensional fibrous structure containing dispersed h -BN as well as a new strategy of preparing more efficient boron-based catalysts in the ODHP process.
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Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Meng Hao,Yang Yusen,Shen Tianyao,Yin Zhiming,Wang Lei,Liu Wei,Yin Pan,Ren Zhen,Zheng Lirong,Zhang Jian,Xiao Feng-Shou,Wei Min
Copper-based catalysts serve as the predominant methanol steam reforming material although several fundamental issues remain ambiguous such as the identity of active center and the aspects of reaction mechanism. Herein, we prepare Cu/Cu(Al)O x catalysts with amorphous alumina-stabilized Cu 2 O adjoining Cu nanoparticle to provide Cu 0 −Cu + sites. The optimized catalyst exhibits 99.5% CH 3 OH conversion with a corresponding H 2 production rate of 110.8 μmol s −1 g cat −1 with stability over 300 h at 240 °C. A binary function correlation between the CH 3 OH reaction rate and surface concentrations of Cu 0 and Cu + is established based on kinetic studies. Intrinsic active sites in the catalyst are investigated with in situ spectroscopy characterization and theoretical calculations. Namely, we find that important oxygen-containing intermediates (CH 3 O* and HCOO*) adsorb at Cu 0 −Cu + sites with a moderate adsorption strength, which promotes electron transfer from the catalyst to surface species and significantly reduces the reaction barrier of the C−H bond cleavage in CH 3 O* and HCOO* intermediates.
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Nature Communications
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2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Li Guowei,Jiang Shihui,Liu Aijun,Ye Lixiang,Ke Jianxi,Liu Caiping,Chen Lian,Liu Yongsheng,Hong Maochun
Crystal-field perturbation is theoretically the most direct and effective method of achieving highly efficient photoluminescence from trivalent lanthanide (Ln 3+ ) ions through breaking the parity-forbidden nature of their 4 f -transitions. However, exerting such crystal-field perturbation remains an arduous task even in well-developed Ln 3+ -doped luminescent nanocrystals (NCs). Herein, we report crystal-field perturbation through interstitial H + -doping in orthorhombic-phase NaMgF 3 :Ln 3+ NCs and achieve a three-orders-of-magnitude emission amplification without a distinct lattice distortion. Mechanistic studies reveal that the interstitial H + ions perturb the local charge density distribution, leading to anisotropic polarization of the F − ligand, which affects the highly symmetric Ln 3+ -substituted [MgF 6 ] 4− octahedral clusters. This effectively alleviates the parity-forbidden selective rule to enhance the 4 f –4 f radiative transition rate of the Ln 3+ emitter and is directly corroborated by the apparent shortening of the radiative recombination lifetime. The interstitially H + -doped NaMgF 3 :Yb/Er NCs are successfully used as bioimaging agents for real-time vascular imaging. These findings provide concrete evidence for crystal-field perturbation effects and promote the design of Ln 3+ -doped luminescent NCs with high brightness.
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ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Shuang Yang,Yinan Lao,Wenjin Yu,Zhenyu Tang,Haoqing Guo,Ganghong Liu,Bo Qu,Lixin Xiao,Zhijian Chen
Tin-based perovskites comprise one of the preferred nontoxic alternatives to Pb-based perovskites due to their desirable optoelectronic properties. However, there remains a crucial stability problem due to the property of Sn2+ oxidation. In this study, we reported stable tin-based perovskite nanocrystals (NCs) using stannous acetate as the Sn2+ source because of its stronger Sn–O bonding. To prevent the oxidation of Sn2+, a thin layer of CsBr coverage was formed in situ; tin-based perovskite NCs, CsxSnBrx+2@CsBr (1 < x < 4), show a high photoluminescence quantum yield (PLQY) of 78.2% and high stability. The measured lifetime of PLQY decrease to half of the initial value is ∼1287 h under ambient conditions and ∼2200 h under a nitrogen atmosphere, respectively. Furthermore, the as-fabricated light-emitting diodes based on CsxSnBrx+2@CsBr NCs as the emitting layer exhibit a maximum luminescence of 16 cd/m2 and an external quantum efficiency of 0.035% with peaks at 451 and 615 nm, corresponding to the emissions of CsBr and CsxSnBrx+2, respectively. This work provided a new way to obtain stable Sn-based perovskite NCs and exhibited their potential for application in white light-emitting diodes (LEDs).
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JOURNAL OF SOLID STATE CHEMISTRY
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2023
·
IF 3.3
Binbin Zhang,Huizhong Zhao,Yajie Gao,Qingge Wang,Zhihao Xi,Kui Wang
On the basis of the method used by Reinsch and Solovyeva, the aluminum based MOF material CAU-10-H (CAU stand for Christian-Albrechts-University) was synthesized by multiplying the amount of aluminum sulfate octahydrate and isophthalic acid by 10 times. CAU-10-H (b) is obtained after washing. In order to improve the water vapor adsorption performance of pure CAU-10-H (b), lithium chloride (LiCl) solution was compounded with CAU-10-H (b) by impregnation method to obtain a composite adsorbent CAU-10-H (L) and its adsorption characteristics were studied. The results showed that the composite adsorbent showed good adsorption and desorption performance under test conditions. Among them, the equilibrium adsorption capacity of the composite adsorbent with 33.1% LiCl content is 0.5007 g/g after 30 cycles, which is about 1.675 times of the adsorption capacity of pure CAU-10-H (b) under the same conditions. This shows the potential of the composite adsorbent to be used in the air-water extraction system.
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PROGRESS IN ORGANIC COATINGS
·
2019
·
IF 3.42
Bingjie Zou,Xijiang Chang,Jingxia Yang,Shuchuan Wang,Jingli Xu,Shirong Wang,Seiji Samukawa,Lidong Wang
h-BN nanoflakes were treated in three plasma gases (Ar、Ar+H 2 (4:1)、Ar + NH 3 (4:1)) for surface modification. The structure characterization (XRD, IR, XPS etc.) of h-BN indicated that the plasma treatment not only enlarged the interlayer distance of h-BN, but also increased the NH/OH surface groups and the ratio of exfoliated h-BN planes. The plasma treated h-BN exhibited better dispersion and stronger Fe 2+ holding ability in acrylic resin than the pristine h-BN, resulting in smaller corrosion current density (i corr ) and larger charge transfer resistance for the acrylic coating on low carbon steel, especially treated in Ar + NH 3 (4:1).
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Journal of Chemistry
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2019
·
IF 1.727
Song-qi Hu,Yin Wang,Lin-lin Liu
Hexagonal boron nitride (h-BN) powders were fabricated by the combustion synthesis with B/KNO3/HMX (octogen) mixtures as reactants. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were adopted to investigate the phase composition and the chemical composition of the products, respectively. The morphology and resistance to oxidation were studied by scanning electron microscopy (SEM) and thermogravimetry (TGA), respectively. The characterization results showed that the h-BN which was produced through this method has high purity and exhibits excellent resistance to oxidation. The purity of h-BN is improved with the increasing content of HMX in reactants with boron carbide (B4C) and boron oxide (B2O3) as main impurity, but conversely, the yields are obviously decreased. Taking the comprehensive consideration of the purity and the yields together, the optimal molar ratio of B/KNO3/HMX is 10 : 1 : 4. In addition, the experimental results indicated that the crystalline grain size grows with the increasing content of HMX. The method explored in this study does not need expensive processing facilities and equipment, which is a preferable approach for the laboratory to prepare h-BN of high purity.
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