ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Yanpeng Huang,Qiong Wu,Jingfan Yan,Fumin Chu,Yuming Xu,Dongmin Li,Hongjia Zhang,Sen Yang
Biochar loaded with MgO is a promising adsorbent for the removal and recovery of phosphate from aqueous solutions. However, its phosphate adsorption capacity is unsatisfactory, especially at low phosphate concentrations. Loading nanoscale MgO onto biochar is an effective strategy. Here, ultrafine MgO nanoparticles and MgO nanosheets were loaded onto biochar from steam-exploded straw (UMB and SMB) via an impregnation-precipitation-pyrolysis method. The crystal sizes of ultrafine MgO nanoparticles and MgO nanosheets were about 6–8 nm and 10–16 nm, respectively. The phosphate adsorption capacity of UMB at C 0 = 100 mg P L −1 was 219.4 mg P g −1 , which was higher than that of SMB (164.9 mg P g −1 ). The results suggest that surface precipitation was the dominant adsorption mechanism and the hydration process and the smaller particle size of MgO may play a key role in the superior phosphate removal by UMB. Removal tests in real low-concentration phosphate water samples showed that 0.05 g L −1 UMB could reduce the phosphate concentration from 0.17 mg P L −1 to 0.01 mg P L −1 . In addition, phosphate could be desorbed from UMB in varying environments, and therefore has the potential to be used in fertilizer production or directly as a slow-release fertilizer.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2012
·Vol. 63
·期 3
·495-500
·
IF 1.632
Lu Junwen,Wang Wei,Zhang Aiqing,Tan Fatang,Qiao Xueliang
Hybrid nanocomposite films of magnesium oxide (MgO) in fluorinated polyimide (PI) from 4, 4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 4, 4′-Diaminodiphenyl ether (ODA) have been successfully fabricated via an in situ sol–gel polymerization technique. The MgO content in hybrid films was varied from 0 to 5 wt%. The hybrid films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet–visible (UV–Vis) spectroscopy and thermal gravimetric analyses (TGA). The results of FTIR, XRD and FESEM showed that the MgO nanoparticles were well dispersed in the polymer matrix due to the coordination between the carbonyl group of polymers and Mg atom, and the as-prepared hybrid films exhibited excellent optical transparency in the visible region and good UV-shielding properties in the UV region. Although the thermal stability of the hybrid films is slight inferior to pure PI, it is still good for the practical application below the temperature of 300 °C.
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
Energy Technology
·
2018
·Vol. 7
·期 8
·1800829
·
IF 3.175
Bin Xiao,Peng-bo Wang,Zhen-jiang He,Zhuo Yang,Lin-bo Tang,Chang-sheng An,Jun-chao Zheng
0.5Li 2 MnO 3 ·0.5LiNi 0.5 Mn 0.3 Co 0.2 O 2 cathode materials with nano-MgO and nano-TiO 2 coating layers are synthesized via a facile approach. These nanocoating layers with a thickness of ≈20 nm are homogeneously coated on the surface of the materials. With the nano-MgO and nano-TiO 2 coating layers, the modified materials deliver excellent electrochemical performance. Nano-MgO-coated and nano-TiO 2 -coated Li-rich materials exhibit 147.56 and 137.96 mAh g −1 after 100 cycles at 1C rate and deliver 156.13 and 130.69 mAh g −1 at 2C rate, respectively, in the voltage range of 2.0–4.8 V. The materials with nano-MgO and nano-TiO 2 coating layers also show a high discharge voltage retention of more than 90% after 50 cycles, low impedance for Li + migration, and high diffusion coefficients of the lithium ions. Nano-MgO and nano-TiO 2 coating layers help decrease the content of Li 2 CO 3 on the surface of the materials and suppress side reactions. Thus, these materials play a significant role in strengthening the electrochemical performance of Li-rich cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2023
·
IF 6.4
Jinjie Zhang,Guanhua Zhang,Yanping Du,Guomin Cui,Wei Lu,Qiguo Yang
Improving the thermal performance of mini-channels is crucial. The nature of working nanofluids and the mini-channel structure can have a significant impact on the thermal efficiency of mini-channels. This study investigated the flow and heat transfer characteristics of a manifold mini-channel heat sink (MCHS) structure. The working fluids were composite nano-phase change emulsions (NPCE), which were prepared from eicosane, eicosanol, and metal oxide particles (nano-MgO). They possess low supercooling, high thermal conductivity, and high stability. Using these NPCEs, convective heat transfer studies were conducted in the two mini-channels. The impacts of the channel type, NPCEs, and Re on the heat transfer characteristics, flow characteristics, and overall performance were investigated. The results showed that the prepared NPCE can improve the heat transfer coefficient in mini-channels compared to water. The incorporation of nano-MgO particles effectively enhanced the heat transfer capacity with the highest enhancement (17.7%) in the heat transfer coefficient compared to water. The addition of alcohol further enhanced the heat transfer performance. A mixture of 6 wt% eicosane + 1 wt% nano-MgO + 0.6 wt% eicosanol yielded the highest enhancement in the heat transfer coefficient of 29.7%. In addition, a manifold mini-channel was found to have a better comprehensive performance than a rectangular mini-channel. The maximum reductions in pressure drop and thermal resistance of the manifold MCHS were 51.2% and 53.9%, respectively, compared to the rectangular mini-channel. Overall, the evaluated performance indicators of the manifold MCHS with composite nanofluid were 17.9% higher than those of the rectangular MCHS.
研究领域:
工程热物理
·
纳米材料科学
✓ 已验证
产品关联
DOI
高影响因子
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