RSC Advances
·
2016
·Vol. 6
·期 112
·111539-111548
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IF 3.289
Hui Deng,Shi-Xi Zhao,Xia Wu,Lei Wei,Yu-Feng Deng,Ce-Wen Nan
The chief drawback of Li2MnSiO4 cathode materials is structural instability deriving from the transformation of [MnO4] tetrahedra to [MnO6] octahedra during oxidation from Mn(II) to Mn(III) and the Jahn–Teller effect especially from Mn(III) to Mn(IV). Based on the theory that Ni2+ could keep the [NiO4] ligand unchanged and stable during oxidation/reduction, [NiO4] tetrahedra may behave as a regional structural framework to support the total crystal lattice and alleviate structural distortion partially. In this paper we synthesize nano-Li2Mn1−xNixSiO4/C samples with a small amount of Ni as the dopant via a hydrothermal route. Firstly, we discuss the existential state of Ni through XPS spectra, and demonstrate that both Ni2+ and metallic Ni coexist, especially Ni2+ could improve structural stability. The influence of Ni doping on morphology, structural stability, and electrochemical performance is discussed through Raman spectroscopy and electrochemical tests below. It is confirmed that there exists an optimal Ni content under which the optimal performance is displayed. In our work, the optimum Ni content is 5.0%, and the maximal discharge capacity achieved is 235 mA h g−1 for the 5.0% Ni doped sample in the first cycle.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Dashuang Fu,Fang He,Haiyi Tian,Jiahao Li,Jieming Zhang,Zheng Kang,Yunkai Wu,Xu Wang
The development of lead-free dielectric capacitors with high recoverable energy storage density and high energy storage efficiency is important for improving the overall performance of electronic and power systems. BaTiO 3 (BTO) is one of the most common ferroelectric materials and has attracted much attention for energy storage applications in the past decades due to its excellent dielectric and ferroelectric properties. However, high remnant polarization and low electrical breakdown strength of BTO limit its development in energy storage applications. Many efforts (e.g., elements doping, interface/heterostructure, etc.) have been made to improve the energy storage density of BTO thin films. In this paper, Ba 1-x Ni x TiO 3 thin films (x = 0, 0.02, 0.04, 0.06, 0.08; abbreviated as BN x T) were synthesized via sol-gel and spin-coated method. The effect of Ni doping on the structural, dielectric, ferroelectric and energy storage properties of BTO thin films has been studied. The results confirmed that with the increase of Ni doping, a second phase arises and the dielectric constant decreases. While appropriate Ni doping led to the improvement of the breakdown strength, further increase of Ni deteriorated the energy storage because of the high oxygen vacancy. Finally, optimized energy storage performance was obtained for BN 0.04 T thin film: dielectric constant of 401, dielectric loss of 0.002, recoverable energy density of 20.2 J/cm 3 and energy storage efficiency of 83.6% at 965 kV/cm. Meanwhile, the remnant and maximum polarization of the films were 0.06 μC/cm 2 and 50 μC/cm 2 , respectively. BN 0.04 T thin film has an excellent application prospect and is expected to appear as a component in the future composite energy storage film system.
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2012
·
IF 4.525
Man Luo,Yong Liu,Juncheng Hu,Hang Liu,Jinlin Li
CdS and Ni-doped CdS hollow spheres were synthesized via a simple template-free one-pot method. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectroscopy analysis, X-ray photoelectron spectroscopy, and UV–vis absorption spectroscopy. The formation mechanism for the Ni-doped CdS hollow spheres was discussed. The prepared CdS and Ni-doped CdS hollow spheres showed the superior photocatalytic activity for the degradation of RhB under visible light (λ > 420 nm) irradiation, and 1.2 mol % Ni-doped CdS hollow spheres were found to be highly efficient for organic pollutants RhB and phenol removal. Moreover, this catalyst showed improved stability, and the activity did not decrease significantly after four recycles. The unique hollow spheres structure may favor the harvesting of exciting light due to multiple scattering within the interior space, and the doping of Ni2+ may facilitate the generation of electrons and holes pairs and inhibit their recombination rate by act as a temporary trapping sites of photoinduced electrons.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2025
·
IF 3.5
Zhao Rongxiang,Wang Hongli,Li Xiuping
The introduction of oxygen vacancies on the surface of catalysts is an important way to improve the performance of catalysis for oxidative desulfurization. In this study, Ni-doped CoMoO 4 catalysts with a significant number of oxygen vacancies were synthesized using hydrothermal methods. The structure of the catalysts was characterized through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N 2 adsorption–desorption techniques, and UV–visible diffuse reflectance (UV–Vis DRS). Compared to CoMoO 4 , the specific surface area of Ni-CoMoO 4 decreased, but the performance of catalysis is improved due to the increased number of oxygen vacancies. The oxidative desulfurization experiments showed that catalytic activity was significantly enhanced by Ni doping. The optimum reaction conditions were determined to be a Ni/Co molar ratio of 1:20, a reaction temperature of 110 °C, a catalyst dose of 0.05 g, and an oxygen flow rate of 150 mL/min. The desulfurization rate of dibenzothiophene (DBT) in model oil could be as high as 96% under the optimum reaction conditions. The desulfurization mechanism of the catalyst was investigated by free radical-trapped experiments. This study proposes a novel strategy for oxidative desulfurization using metal-doped compounds with abundant oxygen vacancies as catalysts. Graphical abstract An inorganic material Ni-CoMoO 4 with a number of oxygen vacancies was synthesized by hydrothermal method and applied for removal of sulfur-containing compounds. It is necessary for ecological and environmental demands. This work provides a new idea for oxidative desulfurization using metal-doping compound containing a number of oxygen vacancies as catalysts.
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DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Wenpeng Hong,Yuhang Li,Haifeng Jiang,Yu Zhang,Wei Jia,Meng Song
Catalytic steam gasification is a promising route for converting plastic waste into valuable gaseous products. This work explores the heterogeneous catalytic gasification behavior of polystyrene (PS) in a two-stage fixed bed system, as well as the promotion mechanism for the generation of gaseous hydrocarbons. The obtained results indicate that adding MnCo 2 O 4 catalyst can effectively promote the formation of gaseous hydrocarbons. Further, the incorporation of Cu strengthens the above reaction process, resulting in a yield of 85.08 mmol/g for the C 1 -C 3 gaseous hydrocarbons. However, the doping of Ni has a negative effect on the generation of gaseous hydrocarbons. Moreover, an increase in the flow rate of steam within the system results in an initial rise followed by a decline in the yield of gaseous hydrocarbons. The optimal steam inflow is determined at 0.14 mL/min. The cycling test results of the catalyst show that the yield of the gaseous components of C 1 -C 3 can still be maintained at about 80 % of the initial state after five cycles. Finally, the synergistic pathway of steam and catalyst in PS gasification is elucidated. These works provide important and valuable guidance for the preparation of high-value gas-phase hydrocarbon products from waste plastics.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Jie Xu,Ming Li,Lvye Yang,Jianhao Qiu,Qian Chen,Xiongfei Zhang,Yi Feng,Jianfeng Yao
Oxygen vacancies are efficient to promote the separation of photogenerated electrons and holes, thereby enhancing the photocatalytic performance of the catalyst. In this work, Ni-doped ZnO with oxygen vacancies was successfully synthesized. 3ZnO with 3 wt% of Ni 2+ doping has an optimum photocatalytic activity. The optimal depolymerization rate of sodium lignosulfonate (SLS) was 94%, and the optimal yields of vanillic acid and guaiacol were 9.3% and 1.5%, respectively. 3ZnO can effectively depolymerize SLS to valuable products, CO 2 and H 2 O due to proper concentration of surface oxygen vacancies induced by Ni 2+ doped, which promotes the formation of •O 2 – . •O 2 – is considered to be more conducive to depolymerization of SLS to valuable products. Proper concentration of oxygen vacancies is very necessary for depolymerizing SLS into valuable products. This work will give an innovative vision for efficient depolymerizing biomass to valuable products through photocatalytic reactions.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Songlin Li,Min Zhang,Zhaohui Lei,Jie Gao,Pengfei Cheng,Hai Wang
Water vapor causes the baseline resistance, response, recovery time, and long-term stability of the metal oxide semiconductor (MOS) gas sensors to change in different humidity. Combining first-principle and experimental can provide an in-depth understanding of the sensing mechanism from the atomic and molecular scales. In this work, we examined the humidity sensitivity of different concentrations of Ni-doped Co 3 O 4 in detail. Co 48 O 64 (1 1 0) and Co 48 O 64 (1 1 1) were constructed by HR-TEM and doped with single, double, and treble Ni atoms on both surfaces. We calculated the adsorption of water and n-butanol molecule on these eight surfaces. The results show that Ni doping improves the moisture resistance properties of Co 48 O 64 (1 1 0) and Co 48 O 64 (1 1 1), and the sensing properties of C 3 H 9 OH adsorbed on Ni 2 Co 46 O 64 (1 1 0) and Ni 2 Co 46 O 64 (1 1 1) are higher than single and treble Ni atoms doping. To investigate the humidity sensitivity further, we synthesized nanorods Co 3 O 4 with and without Ni doping. The experimental results showed that the humidity sensitivity of Ni-Co 3 O 4 was significantly lower than that of Co 3 O 4 . The decrease in the response value for the C 3 H 9 OH may be attributed to the change in the concentration of the Ni doping or the difference in the primarily exposed crystal facet.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
ACS Omega
·
2021
·
IF 3.512
Ying Luo,Xiaohui Zhang,Cheng Huang,Xiaole Han,Qingqing Jiang,Tengfei Zhou,Haijian Yang,Juncheng Hu
Facilitating charge separation and increasing surface active sites have always been the goals of photocatalysis. Herein, we synthesized a Ni-doped Zn0.8Cd0.2S hollow sphere photocatalyst with a facile one-step hydrothermal method. Energy-dispersive spectroscopy mapping showed the high dispersion of Ni ions in the Zn0.8Cd0.2S hollow spheres. The experimental results confirmed that Ni doping reduced the band structure of the substrate, suppressed the recombination of photo-induced electrons and holes, and provided more reactive sites. Therefore, the photocatalytic activity had been greatly improved. As a consequence, the detected photocatalytic H2 evolution rate increased up to 33.81 mmol·h–1·g–1 over an optimal Ni doping (5 wt %) of Zn0.8Cd0.2S hollow spheres, which was 20.87-fold higher than that of pure CdS. Elemental mapping showed that the Zn element was mainly distributed in the outermost layer of the hollow spheres; this might be the critical factor that enabled Ni-doped ZnxCd1–xS to maintain excellent stability.
研究领域:
材料科学
·
能源科学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 24
·7219-7229
·
IF 6.641
Xiaole Zhang,Dalei Song,Qi Liu,Rongrong Chen,Jindi Hou,Jingyuan Liu,Hongsen Zhang,Jing Yu,Peili Liu,Jun Wang
The reasonable design of semiconductor metal oxides modified by elemental doping and surface functionalization has been proven to be an effective method to improve the gas sensing abilities of chemiresistor-type sensors. In this work, Ni-doped In2O3 nanorods were fabricated via simple oil bath and annealing processes. To further enhance their gas sensing performances, Ag functionalization was carried out by a subsequent chemical reduction process. The experimental results reveal that these composites exhibit excellent formaldehyde sensing performance compared with pure In2O3 nanorods. In particular, 6%-Ag/Ni5.0In presents significantly enhanced gas sensing performance toward 100 ppm formaldehyde gas at a low working temperature (160 °C) with high sensitivity (123.97), fast response speed (1.45 s/58.2 s), and good selectivity and stability. Our research reveals that the improvement in sensing performance toward formaldehyde can be attributed to the large specific surface area, high relative contents of OV and OC components, electronic sensitization and the catalytic effect of Ag. The results provide an effective strategy to achieve excellent gas sensing performance for formaldehyde gas sensors.
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Bogu Liu,Bao Zhang,Ying Wu,Wei Lv,Shixue Zhou
Transition metals, including Ni, show good catalytic activity in the hydrogen storage reaction of Mg. In the present paper, first-principles calculation is performed to predict and analyze the hydriding reaction of Ni-incorporated Mg and experimental study is used to verify the accuracy of the forecast. Theoretical studies show that the hydriding reaction of Ni-incorporated Mg is a diffusion-controlled process. With Ni incorporation, the energy barrier of H 2 dissociation is significantly decreased and the diffusion becomes the limiting step. Experimental studies confirm the results of theoretical studies. Besides, the material with Ni incorporation shows excellent activation performance and rapid absorption rates, leading to a high hydrogen content of 4.1 wt% in 60 s under 240 °C 3.0 MPa H 2 and a low activation energy of 56.1 kJ mol −1 versus 0.4 wt% and 73.5 kJ mol −1 for the material without Ni incorporation. Atomic Ni only plays a role of catalyst.
研究领域:
材料科学
·
物理化学
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DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2019
·Vol. 23
·期 11
·3031-3041
·
IF 2.531
Deng Yafeng,Ma Zhanhong,Ren Fengzhang,Wang Guangxin
In spite of the TiO 2 compact layer (TCL) being widely used, it still needs more study. This paper took Ni-doped TCLs as the research target, using an innovative two-step method perfectly prepared Ni-doped TCLs with different thicknesses. And then on the basis of Ni-doped TCLs, the TiO 2 nanorod array (TNA) films were successfully prepared. The effects of Ni-doped TCLs with different thicknesses on the morphology, structure, and photoelectric performance of TNA films were investigated. The results indicated that Ni-doped TCLs with appropriate thickness can significantly improve performance of TNA films and obtain satisfactory PCE stability with time. Compared with the TNA films based on Ni:TCL5, Ni:TCL10, and Ni:TCL30, the TNA film with Ni:TCL20 exhibited better comprehensive photoelectric performance, the DSSCs based on this TNA film achieved the highest J sc (10.191 mA cm −2 ), V oc (0.574 V), PCE (4.42%), and the most excellent PCE stability with time.
研究领域:
材料科学
·
能源科学
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产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2018
·
IF 4.155
She Houde,Li Liangshan,Zhou Hua,Wang Lei,Huang Jingwei,Wang Qizhao
Selective activation of saturated C–H bond in hydrocarbons to produce high-value-added chemicals is of great significance for chemical synthesis and transformation. Herein, we present a facile procedure to achieve Ni-doped CdS nanoparticles with mixed (cubic and hexagonal) phases, as well as its application to the photocatalytic activation of saturated primary C–H bond of toluene and its derivatives. The photocatalytic oxidation rate of toluene into benzaldehyde of formation reached up to 216.7 μmolh−1g−1 under visible light irradiation. The excellent photocatalytic performance of Ni(II)-doped CdS [Ni(II)/CdS] can be attributed to its unique structural assembly with cubic and hexagonal phases and also the addition of Ni ions, together taking effect in promoting the separation of photogenerated charge carriers. The possible reaction mechanism for the photocatalytic selective oxidation is illustrated in this work. The band width of the as-prepared mixed phase CdS is reduced, which can effectively expand the response range and improve photocatalytic performance.
研究领域:
化学合成
·
材料科学
·
光催化反应
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）