COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Nan Wang,Bin Han,Jianbo Wen,Mingwei Liu,Xinjun Li
A novel Mn-doped Fe 2 O 3 modified g-C 3 N 4 nanosheets composite has been prepared for overall water splitting. Structure characterizations reveal that the Mn are successfully doped in the Fe 2 O 3 nanoparticle and a close interface between g-C 3 N 4 and Mn-doped Fe 2 O 3 is obtained. The optimized FMC-10 photocatalyst has a H 2 evolution of 51 μmol h −1 . The improved photocatalytic performance can be ascribed to the synergy effect of both Mn-doped Fe 2 O 3 and g-C 3 N 4 . Doping Fe 2 O 3 with Mn promotes photo-induced charges and increases the charge transfer for the improved conductivity of the bulk Fe 2 O 3 , while favorable contacting with g-C 3 N 4 enhances the charge separation ability.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Zha Jiahao,He Chongjun,Chen Fangzhou,Wang Hongwei,Dong Biao,Liu Lijuan,Xia Mingjun,Deng Chenguang,Li Qian,Lu Yuangang,Chen Huiting
Oxide matrix red-emitting phosphors are deemed as excellent color converters for white light emitting diodes (WLEDs) and laser diodes (LDs). Manganese-doped MgAl 2 O 4 powder was synthesized by a solid-state reaction method at different sintering temperatures. Microstructure shows that grain size is mainly in the range of 0.2–5 μm, and grain agglomeration occurs with increased sintering temperature. XPS analysis indicates that the doped Mn ion exhibits a valence state of + 4 within the MgAl 2 O 4 matrix. The diffraction peak of the phosphors is shifted by the sintering temperature, which affects lattice constant. Upon excitation by 300 nm ultraviolet light, the samples emit asymmetric broadband red light within the range of 620–720 nm, attributed to Mn 4+ ion’s transition from 2 E g to 4 A 2g states. With the increasing temperature, the main emission peak shifts from 677 nm to 650 nm, ascribed to the change in energy level ( 2 E g ) resulting from the reduction of Al 2 O 3 phase. Crystal field theory confirmed that Mn 4+ ions are within a strong crystal field environment created by MgAl 2 O 4 matrix. By affecting particle size and crystallinity, the sintering temperature influences the fluorescence lifetime of the Mn 4+ ion. Notably, these red-emitting phosphors exhibits remarkable thermal stability as their emission intensity remains approximately at 58% of initial intensity even at elevated temperature (435 K). Consequently, Mn 4+ : MgAl 2 O 4 red-emitting phosphors with high thermal stability render them promising candidates for WLED applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Shaobo Ye,Zhentao Du,Zhengxiang Cai,Deliu Ou,Haonan Guo,Qiao Liu,Weiyou Yang,Qing Shi
Molybdenum disulfide (MoS2), a typical earth-abundant material, is an excellent candidate for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), which fundamentally rely on the regulation of the morphology and electronic structure of MoS2. Herein, Mn-doped amorphous MoS2 coated on Mn-doped crystalline Ni3S2 nanorods (Mn–Ni3S2@MoS2), rationally designed core–shell nanorods, have been fabricated via a facile one-step hydrothermal method as highly efficient bifunctional activities for HER and OER in alkaline solution. The target electrodes deliver a high current density of 100 mA cm–2 at a low overpotential of 187 and 310 mV for HER and OER, respectively, outperforming most MoS2-based catalysts. Moreover, a water-splitting cell based on the Mn–Ni3S2@MoS2 electrode requires a voltage of 1.45 V to reach a current density of 10 mA cm–2, which is superior to the state-of-the-art one of those based on noble metal Pt/C–NF∥RuO2–NF and non-noble metal catalysts. The overall enhanced bifunctional catalytic performance is mainly attributed to the abundant catalytically active sites provided by the Mn-doped amorphous MoS2 and the fast pathway for electron/proton transfer facilitated by the Mn-doped crystalline Ni3S2 nanorods. The incorporated Mn dopants and assembled Ni3S2/MoS2 heterostructure effectively regulate the electronic structure with redistributed charge within the core–shell Mn–Ni3S2@MoS2 electrode.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Saudi Chemical Society
·
2015
·
IF 2.523
Lijie Wang,Xi Zhang,Peng Zhang,Zetan Cao,Junhua Hu
Mn doped TiO 2 was synthesized by hydrothermal treatment of titanium boride and manganese chloride. The doped nano powders were fabricated by adding ammonium water into the mother solution which was obtained hydrothermally. The calcination of precursory powders took place at the temperature of 400–600 °C which resulted in the formation of anatase with a small amount of rutile phase. The shift of valence band maximum (VBM) toward the lower binding energies was observed by measuring the position of VBM with reference to the Fermi level, which contributed to the significant red-shift of absorption edges. X-ray photoelectron spectroscopy (XPS) measurement shows that manganese exists in both 4+ and 3+ valance states, which may have a temperate replacing of Ti 4+ because of the charge compensation compared with 2+ and 3+ valence states. The property of photoelectric conversion was detected by evaluating the photocurrent under visible light (>420 nm), and the fluorescence spectra also proved that 6%-Mn doped TiO 2 (DM6) shows a better photoelectric conversion performance.
研究领域:
材料科学
·
光催化
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Yuefeng Gao,Sai Xu,Yanbiao Li,Baojiu Chen
The low photoluminescence quantum yield (PLQY) of CsPbCl 3 perovskite quantum dots (PQDs) poses a significant challenge to their application as ion detection probes. To address this issue, we enhanced the PLQY of CsPbCl 3 PQDs through Mn doping. These enhanced PQDs were then employed as probes for the highly sensitive detection of Cu 2+ ions and temperature. CsPbCl 3 :Mn PQDs with varying Mn/Pb ratios were synthesized via hot injection. The Mn doping introduced an emission band near 600 nm, with intensity increasing alongside doping concentration. At an Mn/Pb ratio of 2.0, the PLQY was enhanced nearly tenfold, from 5.46 % for undoped CsPbCl 3 to 52.48 % for CsPbCl 3 :Mn. CsPbCl 3 :Mn PQDs with the highest PLQY were employed as luminescent probes, utilizing the fluorescence intensity ratio (FIR) technique for copper detection and temperature sensing. The experimental results demonstrated a linear relationship between the FIR and Cu 2+ concentration over the range of 22.12 nM–1600 nM, with 22.12 nM being the calculated limit of detection. Analysis of the emission spectra and fluorescence lifetimes at varying Cu 2+ concentrations revealed that electron transfer from CsPbCl 3 to Cu 2+ induced fluorescence quenching. CsPbCl 3 :Mn exhibits a high relative sensitivity of 15.89 % K −1 at 298 K, along with excellent reversibility. These findings highlight the potential application of CsPbCl 3 :Mn PQDs in both temperature sensing and the analysis of wear metals in engine lubricating oils.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2023
·Vol. 13
·期 7
·1031
·
IF 3.9
Jie Lin,Yihong Ding,Huile Jin,Tianbiao Zeng
Nickel, cobalt, and manganese oxides are easily obtainable non-noble metal catalysts for water splitting. However, the relationship between composition and catalysts’ performance still needs systematic studies. Herein, guided by theoretical calculations, a low overpotential, easily prepared Mn-doped Co3O4was deposited on graphite plates for water splitting. The 30% Mn-doped Co3O4(Co2.1Mn0.9O4) required the lowest overpotential for oxygen evolution reaction (OER), in which the Co2.1Mn0.9O4reached 20, 30, and 50 mA cm−2in the overpotentials of 425, 451, and 487 mV, respectively, with 90% IR compensation. Under overall water-splitting conditions, the current density reached 30 mA cm−2at an overpotential of 0.78 V without IR compensation. Charge density difference analysis illustrates that doped Mn provides electrons for O atoms, and that Mn doping also promotes the electron fluctuation of Co atoms. XPS analysis reveals that Mn-doping increases the chemical valence of the Co atom, and that the doped Mn atom also exhibits higher chemical valence than the Mn of Mn3O4, which is advantageous to boost the form of based-OOH* radical, then decrease the overpotential. Considering the particular simplicity of growing the Co2.1Mn0.9O4on graphite plates, this work is expected to provide a feasible way to develop the high-performance Co-Mn bimetallic oxide for water splitting.Keywords:water splitting;bimetallic oxides;Mn-doped Co3O4;DFT calculation
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Yuxi Meng,Shaomian Liu,Yixi Wang,Wenqing Xu,Jiajian Gao,Sansan Yu,Fabing Su,Tingyu Zhu
Selective catalytic reduction of NO using CO (CO-SCR) is a promising technology for the purification of NO in the flue gas. However, the presence of O 2 significantly inhibits the activity of the CO-SCR catalyst. Herein, we synthesize a hollow Mn-doped CeO 2 @Co 3 O 4 catalyst (Mn-CeO 2 @Co 3 O 4 ), which achieved 82% NO conversion, 100% CO conversion, and 78% N 2 selectivity under 5 vol% O 2 at 200 °C, superior to those of CeO 2 @Co 3 O 4 and Co 3 O 4 @CeO 2 catalysts. The characterization results indicate that the strong electronic interaction at the heterointerfaces between Co 3 O 4 and CeO 2 plays a crucial role in promoting selective adsorption of NO. Furthermore, the Mn doping into the Co 3 O 4 lattice of the catalyst facilitates the conversion of N 2 O intermediates, thereby enhancing the overall activity. This research provides a new strategy for the design and synthesis of CO-SCR catalysts.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2021
·
IF 3.927
Xiao Tian,Jiaxiong Xu
The reported Ag and Mn co-doped Cu 2 ZnSnS 4 thin film has better properties than single-doped Cu 2 ZnSnS 4 . However, the role of Mn in co-doped Cu 2 ZnSnS 4 thin film is still unclear. In this paper, Ag and Mn co-doped Cu 2 ZnSnS 4 thin films with different Mn amounts were prepared by sol-gel method. The crystal phases, morphologies, element compositions, and optical properties of co-doped Cu 2 ZnSnS 4 thin films were characterized to investigate the role of Mn doping. Compared with Ag single-doped Cu 2 ZnSnS 4 thin film, after the incorporation of Mn into Ag-doped Cu 2 ZnSnS 4 , the crystallinity of Cu 2 ZnSnS 4 improves and the micro-strain and dislocation density in the crystal reduce. The valence states of Cu, Zn, Sn, S, Ag, and Mn in co-doped thin film are +1, +2, +4, −2, +1, and +2, respectively. Mn doping can make the grains on the thin film surface enlarge. The MoS 2 interface layer between Cu 2 ZnSnS 4 and Mo becomes thinner and the Urbach energy of Cu 2 ZnSnS 4 decreases after Mn doping. Therefore, Mn in the co-doped Cu 2 ZnSnS 4 thin films shows beneficial effects of enhanced structural, morphological, and optical properties of the films.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
Environmental Technology & Innovation
·
2025
·
IF 7.1
Jing Wang,Siyu Zhang,Lidong Kou,Kunzhen He,Qingyuan Li,Chaojun Wu,Xing Xing,Yanjin Wang
NaBiO 3 is a low-cost photocatalyst with good performance for organic removal. Oxygen vacancies (OVs) play crucial roles in mediating oxygen activation and electron-hole separation during visible light-driven photocatalysis. In this study, Mn ions were doped into the commercial NaBiO 3 by a facile in-situ technique to construct OVs for enhancing sulfamethazine (SMT) removal. By doping 0.001–0.01 mmol of Mn 2 + ions, abundant OVs were formed on the initial NaBiO 3 surface, endowing the as-prepared BiMn x composites (e.g. BiMn 0.001 ) with a fast kinetic (first-order rate constant k 0.68 h −1 ) and a high efficiency (>99 % within 6 h) for SMT degradation. Excellent removal of SMT could be attained across a broad pH range (i.e. pH 0 5–9) using BiMn 0.001 as the photocatalyst, which could harvest full-spectrum LED white light and showed anti-interference to common water co-existent constituents. Increasing solution temperature was also beneficial for SMT removal. Reactive species including 1 O 2 , holes and electrons played dominant roles for SMT removal. Based on HPLC-MS, the degradation intermediates were identified, and a degradation pathway for SMT was formulated in the BiMn x /LED system. The results may shed some light for constructing OVs on catalyst surfaces and preparing LED visible light-responsive photocatalysts for antibiotic removal.
研究领域:
环境科学
·
材料化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 2
·1286-1296
·
IF 2.599
Cao Sheng,Zheng Jinju,Dai Chencheng,Wang Lin,Li Chengming,Yang Weiyou,Shang Minghui
In this report, doping concentration-dependent photoluminescence (PL) properties of Mn-doped ternary Zn–In–S quantum dots (QDs) were studied by using steady-state and time-resolved PL spectroscopy. The QDs PL was firstly significantly intensified with the increasing Mn doping concentration and then decreased after the doping concentration increased up to 7.5 at.%. However, their decay lifetimes exhibit a monotone decrease with Mn doping concentration ranged from 0 to 10 at.%. It can be concluded that the PL intensity was mainly determined by two factors: one was the increased efficiency of energy transfer from host excitons to Mn 2+ ion accepter, and the other was the decreased efficiency of the emission from a Mn 2+ ion, which was caused by the increased component of exposed Mn 2+ ions on QDs surface and the accelerated interaction between adjacent dopants. The competition of above two exciton relaxation dynamics processes determined the trend of the PL intensity, while the latter was responsible for the monotonously decreased lifetime of the Mn 2+ ion emission with the increasing Mn doping concentration.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 8
·1802-1811
·
IF 7.779
Zhi-Han Zuo,Song-Lin Jiang,Zhi-Hao Zhang,Jinhui Liang,Junhao Li,Zhao-Qing Liu,Yibo Chen
How electron traps in a host matrix impact the fluorescence intensity ratio (FIR) thermometry performance in inorganic phosphors is still unclear. In this work, relationships between temperature-dependent photoluminescence, fluorescence intensity ratio-based optical thermometry performance, and concentration of the electron traps have been thoroughly investigated in a Mn-doped ZnGa2O4 spinel system. The results reveal that the sample with a higher concentration of electron traps shows a thermometry sensitivity (Sr) of 3.47% K−1 read from the FIR of the green channel (Mn2+) and the red channel (Mn4+), which is over twice higher than that of the sample with a lower concentration of electron traps. Detailed photoluminescence, thermoluminescence, and first-principles calculations demonstrate that the performance enhancement is dominantly caused by a selective thermally induced emission compensation through the antisite defects in the ZnGa2O4 host. The defects act as electron traps and compensate for the intensity decline of the green channel by releasing electrons at high temperatures while leaving the red channel unaffected, thus increasing the FIR value and the sensitivity. This work shows a significant enhancement effect of the electron traps on the FIR thermometry performance in ZnGa2O4:Mn and provides a novel strategy for thermometry performance enhancement through the manipulation of traps.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 27
·12801-12810
·
IF 3.553
Cao Sheng,Dai Chencheng,Yao Shangfei,Zou Bingsuo,Zhao Jialong
In recent years, light-emitting Mn 2+ -doped nanocrystals (NCs) have been widely studied because of their strong and stable Mn 2+ d–d emission. Herein, highly efficient colloidal Mn 2+ -doped Cd–In–S NCs were prepared by a hot injection strategy. The as-prepared NCs have a cubic crystal structure of CdS host and exhibit strong Mn 2+ emission. The photoluminescence (PL) intensity, PL position, and PL lifetime of this Mn 2+ emission can be adjusted by changing the doping level of Mn 2+ . In particular, by tuning the amount of dopant, the emission color can be varied in the range of 601 nm to 643 nm, which is due to the coordination field environment of Mn 2+ ions changed by the doping concentration. The PL intensity of Mn 2+ is significantly enhanced by the ZnS shell coating, and the highest PL quantum yield can reach 56%, which is attributed to the removal of NCs surface-related defects by shell modification. A prototype LED was fabricated as well by using the as-prepared highly efficient Mn 2+ -doped Cd–In–S NCs as a color conversion material. The Mn 2+ -doped multicomponent semiconductor NCs reported here extend the availability of classical Mn 2+ -doped luminescent materials and provide alternatives for other applications requiring orange-red colloidal NCs.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）