ACS Applied Engineering Materials
·
2022
·
IF 0
Qiang Xue,Jinyuan Zhu,Wenqiao Meng,Kaisong Zhang
The effects of different dispersed phases of MXene nanosheets on polyamide nanofiltration membranes, which was first reported in this investigation, are still unclear. We found that when the MXene nanosheets were dispersed into the aqueous phase, the cross-linking degree of the interfacial polymerization (IP) reaction was low, thereby forming a rough and thin polyamide layer with nanovoids, which increased the pure water flux to 14.1 L m2– h–1 bar–1. When the MXene nanosheets were dispersed into the organic phase, the IP reaction was more thorough with a high degree of cross-linking. Therefore, the salt rejection was higher, with 99.1% of Na2SO4 rejection. We believe that different dispersed phases for 2D nanosheets had different impacts on the IP reaction and polyamide layer and we hope this study can provide ideas for selecting a suitable dispersed phase to develop optimization strategies.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
DOI
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Rongliang Yang,Qingmei Hu,Shaodian Yang,Zhiping Zeng,Hao Zhang,Anyuan Cao,Xuchun Gui
Two-dimensional (2D) MXene nanosheets are attractive for electrochemical energy storage applications due to their superior surface-controlled charge storage capacity. However, the slow ion transport in the closely packed electrode limits their electrochemical performances. Meanwhile, the restricted surface-controlled pseudocapacitance of MXene nanosheets requires to be enhanced. Herein, a well-controlled electrophoretic deposition strategy is developed to disperse Ti3C2Tx nanosheets into a freestanding, porous carbon nanotube (CNT) sponge. The constructed Ti3C2Tx@CNT hybrid sponge can provide high-speed ion-transport pathways for the charge–discharge process. Furthermore, by tuning the deposition potential, the inserted MXene nanosheets can be partially oxidized, boosting the pseudocapacitance performance. A large gravimetric capacitance of 468 F g–1 at 10 mV s–1 and a retention of 79.8% at 100 mV s–1 can be achieved in the Ti3C2Tx@CNT electrode. Meanwhile, the highest areal capacitance of 661 mF cm–2 at 1 mA cm–2 was obtained in the sample with high-loading Ti3C2Tx. For the assembled symmetric supercapacitor, 92.8% of the capacitance is retained after 10 000 cycles of the charge–discharge process at 10 mA cm–2. Thus, this study develops a promising electrophoretic deposition strategy for dispersing 2D MXene nanosheets and boosting their pseudocapacitive performance, resulting in a high-capacitive electrochemical energy storage electrode.
研究领域:
材料科学
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电化学
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能源存储
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纳米技术
·
表面科学
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2023
·Vol. 16
·期 7
·e202201385
·
IF 8.4
Xianyun Peng,Rui Zhang,Yuying Mi,Hsiao-Tsu Wang,Yu-Cheng Huang,Lili Han,Ashley R. Head,Chih-Wen Pao,Xijun Liu,Chung-Li Dong,Qian Liu,Shusheng Zhang,Way-Faung Pong,Jun Luo,Huolin L. Xin
The electrochemical nitrogen (N 2 ) reduction reaction (N 2 RR) under mild conditions is a promising and environmentally friendly alternative to the traditional Haber-Bosch process with high energy consumption and greenhouse emission for the synthesis of ammonia (NH 3 ), but high-yielding production is rendered challenging by the strong nonpolar N≡N bond in N 2 molecules, which hinders their dissociation or activation. In this study, disordered Au nanoclusters anchored on two-dimensional ultrathin Ti 3 C 2 T x MXene nanosheets are explored as highly active and selective electrocatalysts for efficient N 2 -to-NH 3 conversion, exhibiting exceptional activity with an NH 3 yield rate of 88.3±1.7 μg h −1 mg cat. −1 and a faradaic efficiency of 9.3±0.4 %. A combination of in situ near-ambient pressure X-ray photoelectron spectroscopy and operando X-ray absorption fine structure spectroscopy is employed to unveil the uniqueness of this catalyst for N 2 RR. The disordered structure is found to serve as the active site for N 2 chemisorption and activation during the N 2 RR process. Graphical Order from disorder : Au nanoclusters with disordered Au atoms anchored on two-dimensional ultrathin Ti 3 C 2 T x MXene nanosheets are synthesized and prove to be a highly efficient catalyst for the electrochemical synthesis of ammonia. In situ near-ambient pressure X-ray photoelectron spectroscopy and operando XAFS spectroscopy are used to investigate the catalyst.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源化学
·
环境友好合成
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Qinhua Gu,Yujie Qi,Wuxing Hua,Tongxin Shang,Junnan Chen,Luozhen Jiang,Lina Li,Ming Lu,Yixiao Zhang,Xi Liu,Ying Wan,Bingsen Zhang
The shuttle effect caused by soluble lithium polysulfides (LiPSs) deteriorates multiphase transformation reaction kinetics of sulfur species, and gives rise to an unserviceable lithium-sulfur (Li-S) battery. Catalysis, as a process optimization approach, offers an option to eliminate the intrinsic issues. However, exploring and understanding the role of catalysts on electrode reaction remains critical bottlenecks, particularly as they are prone to continuous evolution under complex dynamic environment. Herein, platinum nanoparticles loaded on MXene nanosheets, as sulfur host, and the action of catalysts on the reaction process are investigated via ex-situ monitors upon solid–liquid–solid chemical transformation of sulfur species. These traces confirm that the high performance originates from electron transfer between catalysts and LiPSs, which lowers the nucleation barrier from liquid LiPSs to solid Li 2 S/Li 2 S 2 . Further, the accelerated liquid–solid conversion can alleviate the accumulation of LiPSs, and boost the reaction kinetics in Li-S batteries. The findings corroborate the electronic modulation between catalysts and LiPSs, which is a generalizable strategy to optimize energy conversion efficiency of Li-S batteries.
研究领域:
电化学
·
能源材料
·
纳米催化
·
电池化学
·
表面科学
✓ 已验证
DOI
高影响因子
Small
·
2018
·Vol. 14
·期 41
·1802443
·
IF 9.598
Xiao-Tian Gao,Ying Xie,Xiao-Dong Zhu,Ke-Ning Sun,Xu-Ming Xie,Yi-Tao Liu,Jian-Yong Yu,Bin Ding
Being conductive and flexible, 2D transition metal nitrides and carbides (MXenes) can serve in Li–S batteries as sulfur hosts to increase the conductivity and alleviate the volume expansion. However, the surface functional groups, such as OH and F, weaken the ability of bare MXenes in the chemisorption of polysulfides. Besides, they create numerous hydrogen bonds which make MXenes liable to restack, resulting in substantial loss of active area and, thus, inaccessibility of ions and electrolyte. Herein, a facile, one-step strategy is developed for the growth of TiO 2 quantum dots (QDs) on ultrathin MXene (Ti 3 C 2 T x ) nanosheets by cetyltrimethylammonium bromide-assisted solvothermal synthesis. These QDs act as spacers to isolate the MXene nanosheets from restacking, and preserve their 2D geometry which guarantees larger electrode–electrolyte contact area and higher sulfur loading. The stronger adsorption energy of polysulfides with TiO 2 (than with Ti 3 C 2 T x ), as proven by density functional theory calculations, is essential for better on-site polysulfide retention. The ultrathin nature and protected conductivity ensure rapid ion and electron diffusion, and the excellent flexibility maintains high mechanical integrity. In result, the TiO 2 QDs@MXene/S cathode exhibits significantly improved long-term cyclability and rate capability, disclosing a new opportunity toward fast and stable Li–S batteries.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
电池技术
✓ 已验证
DOI
高影响因子
IEEE TRANSACTIONS ON ELECTRON DEVICES
·
2022
·Vol. 69
·期 12
·6811-6816
·
IF 3.221
Lingling Chu,Chao Xu,Wei Zeng,Chao Nie,Liting Deng,Fang Lei
The optimized metal-semiconductor-metal (MSM) ultraviolet photodetector (UVPD) based on ZnO/MXene/ZnO (ZMZ) sandwich structure is reported here. Since introducing ZMZ, the photoelectric performance of the UVPD has increased, which benefited from the cooperation between the interface electron depletion layer and injection of hot electrons (HEs), triggering the “storage and ejection” behavior of electrons. In general, under 365-nm laser illumination (6.25 mW/cm2), the Responsivity ( ${R}_{p}$ ) and Detectivity ( ${D}^{\ast }$ ) are almost unexpectedly increased by approximately an order of magnitude compared with pristine ZnO-based UVPD. More specifically, the ON/OFF ratio, ${R}_{p}$ , and ${D}^{\ast }$ are about > $10^{{3}}$ , 25.48 mA/W, and > $10^{{11}}$ Jones, respectively. Further, the long-term stable performance of the flexible ZMZ-based UVPD can also be observed after the 1000th bending cycle. And especially, the maximum attenuation coefficient (AC) of photocurrent is only ~5.75%. This work may offer a meaningful strategy for designing and improving the performance of ZnO-based UVPD in the future.
研究领域:
材料科学
·
光电子学
·
纳米科技
·
半导体器件
·
柔性电子学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）