Small
·
2025
·
IF 12.1
Jian Zhang,Xinpeng Wang,Xiaomeng Guo,Wenhao Sang,Qing He,Wen Zhang
Metal–organic frameworks (MOFs) with unique pore architectures and electron-rich sites exhibit an unprecedented iodine capture property. In this contribution, the crystal-size and pore-size-dependent iodine adsorption behavior in MOFs ranging in crystal size from nanometers to micrometers with mesoporous and microporous structures is reported. Nano-sized MOFs have much higher iodine adsorption capacities and rates than Micro-sized MOFs. The pore diffusion for iodine adsorption in MOFs is the rate-controlling step and small-sized MOFs can provide larger external surface areas for iodine transport into adsorbents. Raman spectra suggest the diffusion of iodine molecules is more restricted than iodide species in micropores, and the iodine concentration gradient is more significant in microporous MOF-74 than in mesoporous PCN-222. Molecular simulation indicates iodine transports from mesopores to micropores, and aggregates in micropore cages and framework walls. The electron-rich O/N sites in MOFs attract iodine strongly and restrict iodine diffusion, while the weak interaction between iodine molecules becomes prominent at a high iodine loading amount and thus increases the iodine diffusivity in MOFs. The above result reveals a strong size dependence in iodine adsorption behaviors sensitive to MOFs' intrinsic crystal size, porosity, and guest–host interactions, and MOFs with smaller crystal sizes and mesoporous construction have better iodine capture performance.
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
NANO
·
2017
·
IF 1.025
Longfeng Li,Chengyu Li,Mingzhu Liu,Cheng Wang
The catalytic performance of ceria oxide (CeO 2 ) was greatly influenced by the materials’ structure and surface area. In this paper, CeO 2 porous nanospheres (PNS) with tunable pore and sphere sizes were synthesized by a solvothermal method using diethylene glycol as reaction media. All the as-synthesized CeO 2 PNS presented good adsorption capacity for methyl orange, which makes them potential application in waste water treatment conveniently and economically. The control over the sphere and pore sizes of CeO 2 PNS was achieved by regulating the volume of water bubble in the reaction system, which supplied limited room for the assembling of preformed CeO 2 small nano-precursors.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 30
·18308-18320
·
IF 3.361
Daijun Fu,Qianxin Zhang,Ping Chen,Xiaoshan Zheng,Jun Hao,Peiying Mo,Haijin Liu,Guoguang Liu,Wenying Lv
The extensive use of bisphenol analogues in industry has aggravated the contamination of the water environment, and how to effectively remove them has become a research hotspot. This study presents two imine-based covalent organic frameworks with different pore sizes (COFs) [TAPB (1,3,5-tris(4-aminophenyl)benzene)-Dva (2,5-divinylterephthaldehyde)-PDA (terephthalaldehyde) (COF-1), and TAPB (1,3,5-tris(4-aminophenyl)benzene)-Dva (2,5-divinylterephthaldehyde)-BPDA (biphenyl dialdehyde) (COF-2)], which have achieved the efficient adsorption of bisphenol S (BPS) and bisphenol A (BPA). The maximum adsorption capacity of COF-2 for BPS and BPA obtained from Langmuir isotherms were calculated as 200.00 mg g−1 and 149.25 mg g−1. Both hydrogen bonding and π–π interactions might have been responsible for the adsorption of BPS and BPA on the COFs, where the high adsorption capacity of COFs was due to their unique pore dimensions and structures. Different types of pharmaceutical adsorption studies indicated that COF-2 exhibited a higher adsorption performance for different types of pharmaceuticals than COF-1, and the adsorption capacity was ranked as follows: bisphenol pharmaceuticals > anti-inflammatory pharmaceuticals > sulfa pharmaceuticals. These results confirmed that COFs with larger pore sizes were more conducive to the adsorption of pollutants with smaller molecular dimensions. Moreover, COF-1 and COF-2 possessed excellent pH stability and recyclability, which suggested strong potential applications for these novel adsorbents in the remediation of organic pollutants in natural waterways and aqueous ecosystems.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Jingwen Zhao,Peng Zhu,Huapeng Zhang
A ternary polymer–solvent mixture has already been proposed to prepare surface porous films. However, the uncertainty of the formation mechanism of surface porous films and the multitude of influencing factors with unclear priorities lead to the failure to promote this method. Here, a surface-porous polystyrene (PS) film with a pore size of 0.6 μm was successfully prepared from a ternary PS/poly(ethylene glycol)–tetrahydrofuran (PEG–THF) mixture, using ultrasonic dissolution to provide a dispersion effect. The total polymer concentration, PEG molecular weight, PS/PEG mass ratio, dissolution temperature, and evaporation temperature can help to optimize surface porous structures. Based on the rheological behavior of the ternary PS/PEG–THF mixture and comparative experiments with the traditional dissolution method, the formation mechanism of surface porous structures has been revealed. After dissolution, the ternary mixture should be viewed as a two-phase dispersion, emphasizing the dispersion effect of the dissolution process. The formation of surface pores is derived from the transportation, arrangement, and evaporation of dispersed PEG–THF domains. Thus, the preparation of high-quality surface porous films through a ternary polymer dispersion mainly requires attention to two points: the dissolution and dispersion method and the solvent selection. To obtain submicron surface porous films, a synergistic effect of the two is required.
研究领域:
高分子科学
·
材料工程
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Xiao Wu,Canyu Zhong,Lian Ying Zhang,Jianguo Lu,Qinggang He,Qinghua Zhang,Weiyong Yuan,Chang Ming Li
Three-dimensional (3-D) hierarchical nanoporous graphene (NPG) is highly promising as an electrode material for high-performance supercapacitors, but its fabrication presents formidable challenges. For the first time, 3-D hierarchical NPG has been synthesized via M(RCOO)2·xH2O-mediated controllable self-assembly, in which the noncovalently bonded M(RCOO)2·xH2O simultaneously create metal oxide NPs to serve as spacers and CO2 and H2O as pore generators. The pore size and pore density in the basal planes can be tailored by varying the amount of M(RCOO)2·xH2O. These unique nanostructured graphenes are subsequently investigated as electrode materials for supercapacitors, exhibiting a highly tunable specific capacitance. The most outstanding one achieves a specific capacitance of 186 F g−1 at 0.5 A g−1, surpassing all reported graphene-based supercapacitors in the same electrolyte. In addition, it maintains 79.6% of the capacitance at 20 A g−1, revealing a superior rate performance compared to reported supercapacitors. Furthermore, no significant decrease in capacitance is observed even after 10 000 charge–discharge cycles, demonstrating excellent cycling stability. The ultrahigh capacitance and rate capability are ascribed to the 3-D hierarchical nanoporous structure of graphene with extremely rich edge sites remarkably increasing the surface area and promoting electron transfer and ion diffusion. This study not only presents an innovative strategy for synthesizing unique graphene-based materials with superior capacitive properties but also provides deep scientific insights into the self-assembly mechanism, which can be further extended to fabricate various other 3-D hierarchical nanoporous carbons for diverse important applications.
研究领域:
材料科学
·
纳米技术
·
电化学
·
储能
·
化学合成
✓ 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）