CRYSTENGCOMM
·
2016
·Vol. 18
·期 40
·7737-7744
·
IF 3.849
Ming Zhao,Xinyue Niu,Liao Guan,Haolei Qian,Wei Wang,Jian Sha,Yewu Wang
The growth of high-quality black phosphorus crystals is very important to further study the physical properties of two-dimensional black phosphorus exfoliated from bulk crystals. Herein, we designed a series of experiments to fully understand the growth of black phosphorus crystals and then explore the roles of metals (or alloys) and I elements in its growth process. Finally, we developed a general approach to grow black phosphorus in high yield with high quality and low cost. The work introduced here sheds light on the growth mechanism of black phosphorus crystals and opens up the possibility of the growth of black phosphorus thin film.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Fan Lei,Meng Yang,Feng Jiang,He Zhang,Zhi Zhang,Dazhi Sun
Fluorographene (FG), as an important class of graphene derivatives, has shown great promise in high-performance devices and lubricating materials. However, the large-scale fabrication of high-quality and impurity-free FG nanosheets still remains a main challenge. Herein, a simple liquid-phase exfoliation approach to prepare thin FG nanosheets through the preliminary intercalation of raw graphite fluoride (GrF) particles by N,N-dimethyl formamide molecules, followed by a short-time microwave treatment is reported. Atom force microscopy measurements demonstrate that as-prepared FG nanosheets are comprised of no more than four monolayers after the microwave irradiation. After exfoliation, a small amount of aromatic C C groups in the FG nanosheets are restored, which slightly lowers the F content in FG as compared with the raw GrF. Besides, no other side reaction and impurity elements are introduced during the exfoliation process as revealed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The resultant high-quality FG nanosheets exhibit excellent thermal stability and remarkable lubrication behavior in oil, and thus can be used as a new class of graphene derivatives with the capability of large-scale fabrication for the future device and various other applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 7
·1116
·
IF 2.847
Xingxing Ye,Yexun Shi,Liming Shen,Peng Su,Ningzhong Bao
The “Drying-redissolution” method is promising for the industrial production of high-concentration well-dispersed graphene oxide slurry (GOS). As the potential key step in this method, the spray drying process requires a statistical investigation which guides the large-scale preparation of graphene oxide powder (GOP). This work systematically studies the effects of operating parameters, including nozzle airflow rate (439–895 L·h−1), atomization pressure (0.5–0.7 MPa), and liquid feed rate (3.0–9.0 mL·min−1), by using the response surface methodology integrated Box–Behnken design (RSM–BBD), aiming to produce GOP with high yield and easy re-dispersion. The optimized spray drying condition is predicted to be 439 L·h−1, 0.59 MPa, and 9.0 mL·min−1, at which a powder yield of 70.45% can be achieved. The experimentally obtained GOP has an average particle size of 11.65 μm and the low crumpling degree of the particle morphology results in the good re-dispersibility (97.95%) and excellent adsorption performance (244.1 mg·g−1) of GOP. The GOS prepared by the spray-dried GOP possess low viscosity and high exfoliation efficiency with a single-layer fraction up to 90.8%, exhibiting good prospects for application. This work first applied the RSM–BBD model on the spray drying process of GO, and evidenced the possibility of producing high-quality GO slurry with the “drying-redissolution” method.Keywords:graphene oxide;spray drying;response surface methodology;drying and redissolution
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
GLOBAL CHALLENGES
·
2021
·Vol. 5
·期 4
·2000092
·
IF 3.847
Zhenzhen Guo,You Xu,Fang Yu,Jiacheng Yin,Xianbao Wang
Interfacial water evaporation technology by using solar energy provides one of the promising pathways for freshwater shortage management. However, current research mainly focuses on the improvement of evaporation efficiency by macro or microregulations, ignoring the steam temperature, which is a manifestation of the quality of water. Herein not only is a high-rate solar evaporation achieved but also steam temperature is enhanced by a simple three-tier (wet absorber–air gap–dry absorber) device. In a routine interfacial evaporation test, the evaporator achieves a stable evaporation rate up to 2.15 kg m −2 h −1 under one sun, demonstrating a competitive evaporation rate compared with other reports. With the three-tier device, the steam temperature can increase 33.7%, 41.13%, and 47% without dry absorber under one sun, two sun, and three sun illumination, respectively. At the same time, the steam temperature can be as high as 95.5 °C under three sun intensities. This work provides the possibility of using a simple three-tier device for high-temperature steam generation without extra energy input, which contributes to an idea for future research on the production high-quality water.
研究领域:
可再生能源
·
环境科学
·
材料科学
·
水资源管理
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Jianhui Li,Haiting Yan,Dongfeng Dang,Wei Wei,Lingjie Meng
Graphene has attracted enormous attention due to its unique physical properties and attractive applications in many fields. However, it is an ongoing challenge to develop a facile and low-cost method for the large scale preparation of high-quality graphene (HQGr). In this work, we have developed an improved liquid-phase exfoliation method to mass produce HQGr. This method is quite simple but efficient by exfoliation of graphite in organic solvent with the co-assistance of sodium citrate and water. Remarkably, the concentration of as-exfoliated HQGr was as high as 0.71 mg/mL under optimal conditions, while the oxygen content in HQGr was only 2.39%. After annealing at 500 °C for 2 h in argon atmosphere, the mean conductivity of annealed HQGr was as high as 1.4 × 10 4 S m −1 . Therefore, this facile method for liquid-phase exfoliation of graphite has excellent potential in the industrial-scale production of HQGr for numerous applications in energy storage, optical and electronic fields.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 2
·375
·
IF 4.324
Shuling Shen,Junjie Wang,Zhujun Wu,Zheng Du,Zhihong Tang,Junhe Yang
It is difficult to keep the balance of high quality and high yield for graphene quantum dots (GQDs). Because the quality is uncontrollable during cutting large 2D nanosheets to small 0D nanodots by top-down methods and the yield is low for GQDs with high quality obtained from bottom-up strategy. Here, aphanitic graphite (AG), a low-cost graphite contains a large amount of small graphite nanocrystals with size of about 10 nm is used as the precursor of graphene oxide quantum dots (GO-QDs) for the first time. GO-QDs with high yield and high quality were successfully obtained directly by liquid phase exfoliating AG without high strength cutting. The yield of these GO-QDs can reach up to 40 wt. %, much higher than that obtained from flake graphite (FG) precursor (less than 10 wt. %). The size of GO-QDs can be controlled in 2–10 nm. The average thickness of GO-QDs is about 3 nm, less than 3 layer of graphene sheet. Graphene quantum dots (GQDs) with different surface properties can be easily obtained by simple hydrothermal treatment of GO-QDs, which can be used as highly efficient fluorescent probe. Developing AG as precursor for GQDs offers a way to produce GQDs in a low-cost, highly effective and scalable manner.Keywords:graphene quantum dots;aphanitic graphite;low cost precursor;high yield;high quality
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 10
·5110-5119
·
IF 3.784
Xiaoqing Chen,Hao Li,Pengcheng Zhang,Houlin Hu,Yu Tao,Gaosheng Li
A low-firing SrZnV 2 O 7 ceramic was synthesized via a traditional solid-state sintering route. The phase formation, grain morphology, and dielectric performance were studied in detail. Rietveld refinements based on XRD data revealed that SrZnV 2 O 7 crystallized in the monoclinic space group P2 1 /n, which was further confirmed by TEM analysis. The dense SrZnV 2 O 7 ceramic with an ε r of 11.28, a Qf of 56 660 GHz, and a τ f of −27.2 ppm/°C was yielded at a low sintering temperature of 740°C for 4 h. Its chemical compatibility with Ag was verified via XRD and SEM-EDS analysis, which rendered SrZnV 2 O 7 a prospective candidate for LTCC technology.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2024
·Vol. 26
·期 19
·2544-2550
·
IF 2.6
Songhao Wu,Chicheng Ma,Han Yang,Zichun Liu,Yuanxiao Ma,Ran Yao,Yiyun Zhang,Hua Yang,Xiaoyan Yi,Junxi Wang,Yeliang Wang
High-quality β-(AlxGa1−x)2O3 thin films are fabricated through face-to-face annealing on sapphire substrates covered with epitaxial Ga2O3. Al atoms during high-temperature annealing are uniformly diffused from the sapphire substrate into the overlying Ga2O3 for (AlxGa1−x)2O3 formation. The transformation of the (−201) crystal facet into the (300) crystal facet is observed, which is likely due to the lowest E(hkl)surf of the (100) surface. The crystallinity can be further improved with increasing the annealing temperatures and the duration of the thermal treatment under a tolerance limit of 1400 °C, which also increases the Al content to 0.68 in β-(AlxGa1−x)2O3 with a bandgap of up to 6.0 eV. As a result, highly-crystalline (300)-plane β-(AlxGa1−x)2O3 is obtained with a low X-ray diffraction (XRD) full width at half maximum (FWHM) at around 0.08° (288 arcsec). These findings contribute to the understanding of the preparation of high-quality β-(AlxGa1−x)2O3 films on sapphire substrates.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2023
·
IF 13.1
Tao Chen,Xin Li,Yong Wang,Feng Lin,Ruliang Liu,Wenhua Zhang,Jie Yang,Rongfei Wang,Xiaoming Wen,Bin Meng,Xuhui Xu,Chong Wang
Low-dimensional halide perovskites have become the most promising candidates for X-ray imaging, yet the issues of the poor chemical stability of hybrid halide perovskite, the high poisonousness of lead halides and the relatively low detectivity of the lead-free halide perovskites which seriously restrain its commercialization. Here, we developed a solution inverse temperature crystal growth (ITCG) method to bring-up high quality Cs 3 Cu 2 I 5 crystals with large size of centimeter order, in which the oleic acid (OA) is introduced as an antioxidative ligand to inhibit the oxidation of cuprous ions effieiently, as well as to decelerate the crystallization rate remarkalby. Based on these fine crystals, the vapor deposition technique is empolyed to prepare high quality Cs 3 Cu 2 I 5 films for efficient X-ray imaging. Smooth surface morphology, high light yields and short decay time endow the Cs 3 Cu 2 I 5 films with strong radioluminescence, high resolution (12 lp/mm), low detection limits (53 nGy air /s) and desirable stability. Subsequently, the Cs 3 Cu 2 I 5 films have been applied to the practical radiography which exhibit superior X-ray imaging performance. Our work provides a paradigm to fabricate nonpoisonous and chemically stable inorganic halide perovskite for X-ray imaging.
研究领域:
材料科学
·
放射学
·
晶体生长
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Energy & Environmental Materials
·
2023
·
IF 15
Zhaorui Wen,Chao Liang,Shengwen Li,Gang Wang,Bingchen He,Hao Gu,Junpeng Xie,Hui Pan,Zhenhuang Su,Xingyu Gao,Guo Hong,Shi Chen
Two-dimensional materials have been widely used to tune the growth and energy-level alignment of perovskites. However, their incomplete passivation and chaotic usage amounts are not conducive to the preparation of high-quality perovskite films. Herein, we succeeded in obtaining higher-quality CsPbBr 3 films by introducing large-area monolayer graphene as a stable physical overlay on top of TiO 2 substrates. Benefiting from the inert and atomic smooth graphene surface, the CsPbBr 3 film grown on top by the van der Waal epitaxy has higher crystallinity, improved (100) orientation, and an average domain size of up to 1.22 μm. Meanwhile, a strong downward band bending is observed at the graphene/perovskite interface, improving the electron extraction to the electron transport layers (ETL). As a result, perovskite film grown on graphene has lower photoluminescence (PL) intensity, shorter carrier lifetime, and fewer defects. Finally, a photovoltaic device based on epitaxy CsPbBr 3 film is fabricated, exhibiting power conversion efficiency (PCE) of up to 10.64% and stability over 2000 h in the air.
研究领域:
材料科学
·
光伏技术
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-8
·
IF 3.125
Zhang Zhiliang,Jin Hailun,Wu Chenyu,Ji Jianbing
Graphene, a two-dimensional nanomaterial, has shown tremendous promising applications in a broad range of fields. Mass production of defect-free graphene is a prerequisite for its applications. In this work, by using a needle valve, we propose a simple hydrodynamic-assisted exfoliation method to produce high-quality few-layer graphene flakes. The prepared graphene flakes, with an average layer of 5 (~ 71% less than five layers) and a Raman D/G intensity ratio as low as 0.1, are free of defects and oxidation. The average thickness and length of the few-layer graphene flakes are 2.3 nm (~ 90% < 4 nm) and 1.9 μm (~ 50% in the range of 1–7 μm), respectively. In a lab-scale trial, the concentration of graphene can reach 0.40 g/ml under mild operating conditions (working pressure 20 MPa, 16 cycles), and the corresponding production rate is 0.40 g/h. The hydrodynamic-assisted exfoliation by needle valve potentially offers a simple and efficient method for large-scale production of high-quality graphene.
研究领域:
纳米材料科学
·
材料化学
·
化学工程
·
二维材料
·
工业催化
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 14
·5880-5886
·
IF 9.931
Jing Yang,Xiaofeng Li,Shuang Han,Runzhou Yang,Peng Min,Zhong-Zhen Yu
Low thermal conductivity and poor shape stability have seriously limited the wide application of phase change materials (PCMs). To enhance the thermal conductivity without compromising the latent heat of fusion of PCMs, high-quality graphene aerogels (HGAs) with both a highly conductive network and high porosity are fabricated on the basis of highly processable graphene oxide (GO) pastes. Freeze-drying of the GO pastes fixes their shapes and endows the resultant GO aerogels with high porosity, and high-temperature annealing of the GO aerogels at 2800 °C efficiently removes the oxygen-containing groups of the GO component and heals its defects to get HGAs with high thermally conductive capacity. Due to the interconnecting network with high porosity constructed by the high-quality graphene sheets, the resulting HGAs are highly efficient in improving the thermal conductivity of PCMs at a low graphene loading. After impregnating the porous HGA with 1-octadecanol, the obtained composite with only ∼5.0 wt% of graphene exhibits a satisfactory shape stability, an exceptional thermal conductivity of ∼4.28 W m−1 K−1 that is 18-fold higher than that of neat 1-octadecanol, and a high latent heat of fusion of ∼225.3 J g−1. Such a high performance phase change composite with an excellent shape stability would be very promising for thermal energy storage applications as latent heat storage/release units.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）