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Your search keyword '"Wei, Mingzhi"' showing total 226 results
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226 results on '"Wei, Mingzhi"'

22. Boron-doped NiCoP nanoarrays with wrinkles grown on carbon cloth for hybrid supercapacitor applications.

Author

Zhang, Zhe, Zhang, Xuetao, Tai, Chunqing, Wei, Mingzhi, Lu, Qifang, Guo, Enyan, Si, Conghui, Chen, Shunwei, and Han, Xiujun

Subjects
CARBON fibers, CHARGE transfer kinetics, SUPERCAPACITOR electrodes, SUPERCAPACITORS, DOPING agents (Chemistry), ATOMIC radius, DENSITY functional theory, BORON
Abstract

Heteroatom doping, especially with elements of lower electronegativity and smaller atomic radius, can effectively modulate the electronic structure and surface properties of electron materials, facilitating the electrochemical performance of supercapacitors. Herein, we have designed boron-doped NiCoP nanoarrays grown on carbon cloth (B-NCP-CC) for supercapacitor cathode materials using a simple process method combining hydrothermal, calcined phosphating and boronation processes. The introduction of boron, with lower electronegativity (2.04) and smaller atomic radius (0.85 Å) than phosphorus (2.19 and 1.00 Å), induces electron redistribution and shortens the Ni/Co–B bonds, enhancing their redox activity and charge transfer kinetics. The boron doping greatly enables the B-NiCoP-CC-18 (NiCoP-CC borated for 18 h) cathode material to provide a high capacity of 801 C g−1. The assembled B-NiCoP-CC-18‖‖AC hybrid supercapacitor achieves a high energy density of 73.22 W h kg−1 at a power density of 963.8 W kg−1 and retains 90% capacity after 5000 cycles, significantly improving the stability of nickel-based materials. Besides, density functional theory (DFT) calculations further elucidate that the introduction of boron increases the d-band centers of Ni and Co in NiCoP, promoting the conductivity and enhancing the electrochemical properties. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Isomerization of surface functionalized SWCNTs and the critical influence on photoluminescence: static calculations and excited-state dynamics simulations.

Author

Chen, Shunwei, Li, Yi, Chen, Xinxin, Li, Lingyun, Lu, Qifang, Guo, Enyan, Si, Conghui, Wei, Mingzhi, and Han, Xiujun

Abstract

Single-walled carbon nanotubes (SWCNTs) functionalized with sparse surface chemical groups are promising for a variety of optical applications such as quantum information and bio-imaging. However, the luminescence efficiencies and stability, two key aspects, undoubtedly govern their practical usage. Herein, we assess the surface migration of oxygen and triazine groups on as-modified SWCNT fragments by adopting transition state theory and explore the de-excitation of oxygen-functionalized SWCNT fragments by performing non-adiabatic excited-state dynamics simulations. According to the predicted moderate or even small reaction barriers, the migration of both oxygen and triazine groups is feasible from an sp3 defect configuration forming an energetically more stable sp2 configuration at moderate or even room temperatures. Such isomerization leads to drastically different light emission capabilities as indicated by the large or zero oscillator strengths. During the dynamics simulations, the lowest excited singlet (S1) state rapidly decays in energy within 20 fs and then fluctuates until the end, providing insights into the emission mechanism of SWCNTs. This study highlights the potential intrinsic limitations of surface-functionalized SWCNTs for luminescence applications. [ABSTRACT FROM AUTHOR]

Published
2024
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39. High-Efficiency Pure-Red CsPbI3Quantum Dot Light-Emitting Diodes Enabled by Strongly Electrostatic Potential Solvent and Sequential Ligand Post-treatment Process

Author

Hu, Jingcong, Bi, Chenghao, Ren, Ke, Zhang, Xuetao, Wang, Weiqiang, Ma, Sai, Wei, Mingzhi, Lu, Yue, and Sui, Manling

Abstract

Efficient pure-red emission light-emitting diodes (LEDs) are essential for high-definition displays, yet achieving pure-red emission is hindered by challenges like phase segregation and spectral instability when using halide mixing. Additionally, strongly confined quantum dots (QDs) produced through traditional hot-injection methods face byproduct contamination due to poor solubility of metal halide salts in the solvent octadecene (ODE) at low temperatures. Herein, we introduced a novel method using a benzene-series strongly electrostatic potential solvent instead of ODE to prevent PbI2intermediates and promote their dissolution into [PbI3]−. Increasing methyl groups on benzene yields precisely sized (4.4 ± 0.1 nm) CsPbI3QDs with exceptional properties: a narrow 630 nm PL peak with photoluminescence quantum yield (PLQY) of 97%. Sequential ligand post-treatment optimizes optical and electrical performance of QDs. PeLEDs based on optimized QDs achieve pure-red EL (CIE: 0.700, 0.290) approaching Rec. 2020 standards, with an EQE of 25.2% and T50of 120 min at initial luminance of 107 cd/m2.

Published
2024
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40. Zero-Dimensional/Two-Dimensional Schottky Junction of Mn0.5Cd0.5S/Ti3C2MXene Induces Rapid Electron Transfer and Enrichment for Boosting Photocatalytic H2Production Activity

Author

Zhang, Yue, Zhang, Zhe, Li, Qiancheng, Gao, Xinglong, Lu, Qifang, Guo, Enyan, Si, Conghui, and Wei, Mingzhi

Abstract

Efficient charge separation and transfer in photocatalytic systems continuously enable better water splitting for clean H2evolution. Herein, a feasible in situgrowth hydrothermal strategy by coupling an ultrathin Ti3C2(TC) MXene nanosheet electron acceptor with a Mn0.5Cd0.5S (MCS) nanoparticle donor is introduced to construct a multifunctional donor–acceptor MCS/TC photocatalyst with a strong Schottky junction toward green and sustainable photocatalytic H2production. The strong Schottky junction realizes a rapid carrier directional separation and transportation. The ultrathin TC nanosheets, as an electron acceptor to catalyze proton reduction, can promote the separation of photogenerated electron–hole pairs and provide rich active sites for photocatalytic hydrogen production. Moreover, the optimal MCS/TC-10 (10 wt % TC) photocatalyst provides a highly stable photocatalytic H2activity, up to 3730 μmol h–1g–1, which is 9 times higher than that of Mn0.5Cd0.5S solid solution. This work will inspire the development of design principles for accelerating charge transfer for efficient photocatalytic green H2production.

Published
2024
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