Peroxydisulfate activation by LaNiO3 nanoparticles with different morphologies for the degradation of organic pollutants

Abstract A series of LaNiO3 perovskite nanoparticles with different morphologies, such as spheres, rods and cubes, were prepared through co-precipitation and hydrothermal methods, and used as the catalysts for peroxydisulfate (PDS) activation. The physical and chemical characteristics of LaNiO3 perovskites were performed, including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen isotherm absorption (BET), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). The LaNiO3 with different shape showed different activities in Acid Orange 7 (AO7) degradation. Spheres-like LaNiO3 exhibited the highest catalytic activity, which is probably due to the largest specific surface area, higher proportion of reductive Ni2+ and the higher electron transfer ability. The radical scavenging experiments and electron paramagnetic resonance (EPR) revealed the production of massive sulfate radicals (SO4•−) and hydroxyl radicals (•OH) during the oxidation. Finally, the possible mechanisms of PDS activation and AO7 degradation were proposed. The prepared LaNiO3 perovskites also showed excellent reusability and stability.

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Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽

10.3390/catal10060640 ◽

2020 ◽

Vol 10 (6) ◽

pp. 640

Author(s):

Hideaki Sasaki ◽

Keisuke Sakamoto ◽

Masami Mori ◽

Tatsuaki Sakamoto

Keyword(s):

Electron Microscopy ◽

Solid Solution ◽

Solid Solutions ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Co Precipitation ◽

Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

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Mixed Metal Oxide Interfaces: An Experimental and Theoretical Assessment of Secondary Metal Influences in Metal Impregnated Aluminas

MRS Proceedings ◽

10.1557/proc-368-269 ◽

1994 ◽

Vol 368 ◽

Author(s):

M. Malaty ◽

D. Singh ◽

R. Schaeffer ◽

S. Jansen ◽

S. Lawrence

Keyword(s):

Photoelectron Spectroscopy ◽

Theoretical Calculations ◽

Mixed Metal Oxide ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

X Ray ◽

Mixed Metal ◽

Metal Interactions ◽

Metal Metal ◽

Bimetallic System

ABSTRACTStudies of the mixed-metal interface in metal impregnated alumina have indicated the possibility of much metal-metal and metal-substrate interaction. Studies were carried out on NiCu/Al2O3 system which was evaluated to develop a better understanding of the forces that drive modification of the catalytic selectivity of Ni in the presence of Cu. Electron Paramagnetic Resonance (EPR), Powder X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD) and theoretical calculations were carried out on this bimetallic system, using Ni,Ag/Al2O3 as a reference as Ni shows negligible electron perturbation on co-adsorbance with Ag onto alumina. XRD results indicate that gross modification of the electronic fields of Ni and Cu are due to direct coupling and intercalation into the alumina matrix. As a result of this phenomena, these materials may form a good base for the development of novel ceramics based on mixed-metal interactions where the intermetallic perturbations are driven by the substrate effects.

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Ultrasound enhanced heterogeneous activation of peroxymonosulfate by a Co-NiOx catalyst

Water Science & Technology ◽

10.2166/wst.2017.316 ◽

2017 ◽

Vol 76 (6) ◽

pp. 1436-1446 ◽

Cited By ~ 7

Author(s):

Chenmo Wei ◽

Jing Zhang ◽

Yongli Zhang ◽

Gucheng Zhang ◽

Peng Zhou ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Sol Gel ◽

Maximum Efficiency ◽

Acid Orange 7 ◽

X Ray Diffraction ◽

X Ray ◽

Surface Hydroxyl ◽

Transmission Electron ◽

Initial Ph ◽

Reactive Oxidant

Sulfate radical-based advanced oxidation processes have had considerable attention due to the highly oxidizing function of sulfate radicals (SO4−·) resulting in acceleration of organic pollutants degradation in aqueous environments. A Co-Ni mixed oxide nanocatalyst, which was prepared by the sol-gel method, was employed to activate peroxymonosulfate (PMS, HSO5−) to produce SO4−· with Acid Orange 7 (AO7) selected as a radical probe. The catalyst was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The characterization results indicated that the ingredient of the catalyst had been changed and the amount of surface hydroxyl increased significantly with the addition of Ni. Therefore, it proved that Co-NiOx catalyst was more effective than CoOx to activate PMS. Moreover, ultrasound (US) can increase the degradation rate of AO7 and US/Co-NiOx/PMS system. This study also focused on some synthesis parameters and the system reached the maximum efficiency under the condition when [PMS] = 0.4 mM, [catalyst] = 0.28 g/L, Pus = 200 W. The AO7 removal in these systems follows first order kinetics. Last but not least, quenching studies was conducted which indicated that the amount of hydroxyl radicals (·OH) increases with the increase of initial pH and SO4−· was the primary reactive oxidant for AO7 degradation.

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Quinone-modified metal-organic frameworks MIL-101(Fe) as heterogeneous catalysts of persulfate activation for degradation of aqueous organic pollutants

Water Science & Technology ◽

10.2166/wst.2019.239 ◽

2019 ◽

Vol 79 (12) ◽

pp. 2357-2365 ◽

Cited By ~ 2

Author(s):

Huaisu Guo ◽

Weilin Guo ◽

Yang Liu ◽

Xiaohua Ren

Keyword(s):

Photoelectron Spectroscopy ◽

Heterogeneous Catalysts ◽

Electrochemical Impedance ◽

Metal Organic Framework ◽

Optimum Conditions ◽

X Ray Diffraction ◽

Heterogeneous Fenton ◽

X Ray ◽

Metal Organic ◽

Persulfate Activation

Abstract In this work, quinone-modified metal-organic framework MIL-101(Fe)(Q-MIL-101(Fe)), as a novel heterogeneous Fenton-like catalyst, was synthesized for the activation of persulfate (PS) to remove bisphenol A (BPA). The synthetic Q-MIL-101(Fe) was characterized via X-ray diffraction, scanning electron microscope, Fourier transform infrared, electrochemical impedance spectroscopy, cyclic voltammetry and X-ray photoelectron spectroscopy. As compared to the pure MIL-101(Fe), Q-MIL-101(Fe) displayed better catalytic activity and reusability. The results manifested that the Q-MIL-101(Fe) kept quinone units, which successfully promoted the redox cycling of Fe3+/Fe2+ and enhanced the removal efficiency. In addition, the reaction factors of Q-MIL-101(Fe) were studied (e.g. pH, catalyst dosage, PS concentration and temperature), showing that the optimum conditions were [catalyst] = 0.2 g/L, [BPA] = 60 mg/L, [PS] = 4 mmol/L, pH = 6.79, temperature = 25 °C. On the basis of these findings, the probable mechanism on the heterogeneous activation of PS by Q-MIL-101(Fe) was proposed.

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Effects of Impurity Doping on the Luminescence Performance of Mn4+-Doped Aluminates with the Magnetoplumbite-Type Structure for Plant Cultivation

Materials ◽

10.3390/ma12010086 ◽

2018 ◽

Vol 12 (1) ◽

pp. 86 ◽

Cited By ~ 5

Author(s):

Xiaoshuang Li ◽

Zikun Chen ◽

Bo Wang ◽

Ruizhao Liang ◽

Yongting Li ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Light Emitting Diode ◽

Octahedral Complex ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

Light Emitting ◽

X Ray ◽

Color Changes ◽

Plant Cultivation ◽

Impurity Doping

Mn4+ activated LaMgAl11O19 (LMA/Mn4+) with red emitting phosphor was obtained by sintering under air conditioning. The X-ray diffraction pattern Rietveld refinement results reveal that three six-fold coordinated Al sites are substituted by Mn4+ ions. Furthermore, the chemical valence state of manganese in the LMA host was further confirmed through X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). Photoluminescence emission (PL) and excitation (PLE) spectra of LMA/Mn4+ as well as the lifetime were measured, and the 663 nm emission is ascribed to the 2Eg→4A2g from the 3d3 electrons in the [MnO6]8− octahedral complex. The emission spectrum matches well with the absorption of phytochrome. Temperature-dependent PL spectra show that the color changes of the phosphor at 420 K are 0.0110 for Δx and −0.0109 for Δy. Moreover, doping Zn2+ and Mg2+ ions in the host enhances the emission intensity of Mn4+ ions. These results highlight the potential of LMA/Mn4+ phosphor for a light-emitting diode (LED) plant lamp.

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Synthesis and Characterization of Li0.97K0.03FePO4/Graphene Composites by Carbonthermal Reduction Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.687-691.4327 ◽

2014 ◽

Vol 687-691 ◽

pp. 4327-4330

Author(s):

Yan Wang ◽

Zhe Sheng Feng ◽

Lu Lin Wang ◽

Jin Ju Chen ◽

Zhen Yu He

Keyword(s):

Discharge Capacity ◽

Photoelectron Spectroscopy ◽

Reduction Method ◽

Electrochemical Impedance ◽

Impedance Spectra ◽

X Ray Diffraction ◽

Capacity Retention ◽

Electrochemical Impedance Spectra ◽

X Ray

Li0.97K0.03FePO4 and Li0.97K0.03FePO4/graphene composites were synthesized by carbothermal reduction method using acetylene black as carbon source. The structure and electrochemical properties of the prepared materials were investigated with X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, galvanostatic charge and discharge and electrochemical impedance spectra tests. The results indicated that K doping improves the cyclic stability of samples, the addition of small amounts of graphene results in better electronic properties on sample. Li0.97K0.03FePO4/graphene showed discharge capacity of 158.06 and 90.55 mAh g-1 at 0.1 C and 10 C, respectively. After the 50 cycle test at different rates, the reversible discharge capacity at 0.1 C was 158.58 mAh g-1, indicating the capacity retention ratio of 100.32%.

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MXene/Ag2CrO4 Nanocomposite as Supercapacitors Electrode

Materials ◽

10.3390/ma14206008 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6008

Author(s):

Tahira Yaqoob ◽

Malika Rani ◽

Arshad Mahmood ◽

Rubia Shafique ◽

Safia Khan ◽

...

Keyword(s):

Electrochemical Impedance ◽

Low Cost ◽

Sol Gel ◽

X Ray Diffraction ◽

Energy Storage Devices ◽

X Ray ◽

Storage Devices ◽

Bonding Structure ◽

Electron Transfer Rate Constant ◽

Co Precipitation

MXene/Ag2CrO4 nanocomposite was synthesized effectively by means of superficial low-cost co-precipitation technique in order to inspect its capacitive storage potential for supercapacitors. MXene was etched from MAX powder and Ag2CrO4 spinel was synthesized by an easy sol-gel scheme. X-Ray diffraction (XRD) revealed an addition in inter-planar spacing from 4.7 Å to 6.2 Å while Ag2CrO4 nanoparticles diffused in form of clusters over MXene layers that had been explored by scanning electron microscopy (SEM). Energy dispersive X-Ray (EDX) demonstrated the elemental analysis. Raman spectroscopy opens the gap between bonding structure of as-synthesized nanocomposite. From photoluminence (PL) spectra the energy band gap value 3.86 eV was estimated. Electrode properties were characterized by applying electrochemical observations such as cyclic voltammetry along with electrochemical impedance spectroscopy (EIS) for understanding redox mechanism and electron transfer rate constant Kapp. Additionally, this novel work will be an assessment to analyze the capacitive behavior of electrode in different electrolytes such as in acidic of 0.1 M H2SO4 has specific capacitance Csp = 525 F/g at 10 mVs−1 and much low value in basic of 1 M KOH electrolyte. This paper reflects the novel synthesis and applications of MXene/Ag2CrO4 nanocomposite electrode fabrication in energy storage devices such as supercapacitors.

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Removal of Cesium and Strontium From Radioactive Wastewater by Prussian Blue Nanorods

10.21203/rs.3.rs-1200891/v1 ◽

2022 ◽

Author(s):

Chuqing Yao ◽

Yaodong Dai ◽

Shuquan Chang ◽

Haiqian Zhang

Keyword(s):

Prussian Blue ◽

Photoelectron Spectroscopy ◽

Adsorption Process ◽

Maximum Adsorption Capacity ◽

X Ray Diffraction ◽

X Ray ◽

Radioactive Wastewater ◽

Pseudo Second Order ◽

Co Precipitation ◽

Solvothermal Methods

Abstract In this work, novel Prussian blue tetragonal nanorods were prepared by template-free solvothermal methods for removal of radionuclide Cs and Sr. It was worth that Prussian blue nanorods exhibited the better adsorption performance than co-precipitation PB or Prussian blue analogue composites. Thermodynamic analysis implied that adsorption process was spontaneous and endothermic which was described well with Langmuir isotherm and pseudo-second-order equation, the maximum adsorption capacity of PB nanorod was estimated to be 194.26 mg g-1 and 256.62 mg g-1 for Cs+ and Sr2+. The adsorption mechanism of Cs+ and Sr2+ was studied by X-ray photoelectron spectroscopy, X-ray diffraction and 57Fe Mössbaure spectroscopy, the results revealed that Cs+ entered in PB crystal to generate a new phase, the most of Sr2+ was trapped in internal crystal and the other exchanged Fe2+. Furthermore, the effect of co-existing ions and pH for PB adsorption process were also investigated. The results suggest that PB nanorods were outstanding candidate for removal of Cs+ and Sr2+ from radioactive wastewater.

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Controlled Synthesis of Nanostructured Nickel Oxide Thin Film for Supercapacitor Application

Advanced Science Letters ◽

10.1166/asl.2018.12155 ◽

2018 ◽

Vol 24 (8) ◽

pp. 5587-5592

Author(s):

S. C Bhise ◽

D. V Awale ◽

M. M Vadiyar ◽

S. K Patil ◽

B. N Kokare ◽

...

Keyword(s):

Thin Film ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Oxide Thin Film ◽

Storage Device ◽

Controlled Synthesis ◽

X Ray Diffraction ◽

X Ray ◽

Supercapacitor Application ◽

Nio Thin Film

In the present work we report the controlled synthesis of NiO thin film with nano-leaves like morphology using reflux method. The synthesized NiO electrode is used as working electrode for supercapacitor application. The deposited NiO thin film was characterized using thermogravimetric (TGA) analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The supercapacitor behaviour of NiO was investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy using 3 M KOH electrolyte. The electrochemical results show specific capacitance of 513 F g−1 at 10 mV s−1 scan rate, power density (10.44 kW kg−1), energy density (14 Wh kg−1) and 85% capacitance retention over 5000 cycles. These remarkable results indicate the importance of the NiO nano-leaves electrode in energy storage device.

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Preparation of Nickel and Manganese Dioxide by Co-Precipitation and its Electrochemical Capacitive Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.814.86 ◽

2015 ◽

Vol 814 ◽

pp. 86-90

Author(s):

Qian Qian Li ◽

Run Hua Fan ◽

Yu Jun Bai ◽

Chuan Bing Cheng ◽

Gui Fang Liu ◽

...

Keyword(s):

Specific Capacitance ◽

Manganese Oxides ◽

Electrochemical Impedance ◽

Spherical Particles ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Capacitive Properties ◽

Co Precipitation ◽

Redox Capacitance

The precursor nickel and manganese carbonates were synthesized by co-precipitation with sodium carbonate as precipitant, and then nickel and manganese oxides were gained after calcination. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical characterization was performed using cyclic voltammetry (CV), galvanostatic charge–discharge tests (GCD) and electrochemical impedance spectroscopy (EIS) in a 6mol/L KOH aqueous solution electrolyte. The result showed that the products were the mixture of nickel and manganese oxides and solid solution. nanoparticles and spherical particles were gained by controlling the molar ratio of nickel and manganese. All of the samples exhibited typical Faradic redox capacitance. The specific capacitance was different with the change of nickel and manganese molar ratio. The specific capacitance (Cs) reached 130F/g at 1A/g when the ratio was 2:1.

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