The combined template of Mn(CH3COO)2, KCl, and CO(NH2)2 is a strategy for the structural control and functionalization of porous carbons. Waste peach gum is used to achieve the orderly design of N, ...O-codoped lamellar porous carbon (NLPC). The prepared carbon electrode obtains a mass specific capacitance of 402 F g–1 at an ampere density of 0.5 A g–1 in 6 M KOH, long cycle stability (99.5% mass specific capacitance retained after 10000 cycles), and rich surface heteroatoms (O is 9.53 at. %, N is 14.04 at. %). In addition, the prepared symmetrical supercapacitor (NLPC-700//NLPC-700) has excellent cycle life (99.1% specific capacitance). Therefore, this work proposes a design of integrating heteroatom doping and pore size engineering into carbon materials that can branch out to other fields such as energy storage and energy conversion.
Fe2B coating was prepared on low-carbon steel by surface alloying. A series of experiments were carried out to examine some surface properties of boride coating. The surface heat treatment of coated ...low-carbon steel was performed at 700°C, 800°C and 900°C for 2h, 4h, 6h and 8h under hydrogen atmosphere. The boride coating was revealed by XRD analysis and the microstructure of the boride coating was analyzed by scanning electron microscopy (SEM). Depending on the temperature and time of the process, the hardness of the borided low-carbon steel ranged from 99 to 1100HV. The hardness showed a maximum (about 1100HV) at 900°C for 8h. The corrosion resistance of the borided samples was evaluated by the Tafel polarization and electrochemical impedance spectroscopy (EIS). Shift in the corrosion potential (Ecorr) towards the noble direction was observed, together with decrease in the corrosion current density (Icorr), increase in the charge transfer resistance (Rct) and decrease in the capacitance (Cc), which indicated an improvement in corrosion resistance with increasing temperature and time of the treatment.
► A compact morphology was observed by preparing Fe2B coating. ► XRD studies confirm that the boride coating was constituted of Fe2B phase. ► The hardness increased with increasing heat treatment time and temperature. ► The boride coating provides corrosion protection, and then defined barrier properties.
Herein, a non-polluting and simple electrodeposition strategy is presented by us for fabricating ternary iron cobalt transition metal sulfide (FeCoS) on Ni foam with nanosheet arrays, which are used ...as cathode materials for asymmetric supercapacitors. The FeCoS-15 nanosheet arrays reveal an admirable specific capacitance of 3741.03 F g
−1
when the current density is 1 A g
−1
and also exhibit a fantastic cycling performance with 92.84% capacitance retention at 20 A g
−1
up to 10,000 cycles. Furthermore, the asymmetric supercapacitors using the FeCoS-15 nanosheet arrays as the positive electrode and the activated carbon (AC) as the negative electrodes demonstrate remarkable electrochemical performance. Our device exhibits an energy density of 54.08 Wh kg
−1
with the power density of 800 W kg
−1
, achieving an impressive cycling retention of 85.64% over 10,000 cycles. The excellent results show that FeCoS nanosheet array materials have a roomy application prospect for high-performance asymmetric supercapacitors.
Platinum group compounds are currently the best performance hydrogen evolution catalysts, but their high price and low abundance limit their large-scale applications. Therefore, noble-metal-free ...catalysts have become a focus in the research of hydrogen evolution reactions (HER). In this work, we developed a noble-metal-free HER catalyst consisting of Co
3
O
4
supported on N-doped carbon nanotubes (Co
3
O
4
-NCTs). The Co
3
O
4
-NCT catalyst synthesized by stirring, heating, and high-temperature calcination was studied, showing a very low Tafel plot (32.3 mV dec
−1
) in an alkaline solution and good stability for hydrogen evolution reactions. In addition, the material synthesis method is simple, the experimental raw materials are cheap and easy to obtain, and it is expected to be suitable for large-scale industrial production.
The main purpose of this study was to precipitate indium and extract indium from pressure oxidative leaching liquor using sodium tripolyphosphate. Various influential factors were evaluated in the ...paper, such as pH value, temperature, reaction time, molar ratio of Na
5P
3O
10/indium and metal ions including Fe
3+, Fe
2+, Cu
2+, Cd
2+, Zn
2+, etc. Over 95% of the indium was precipitated under the conditions employed, e.g. at a pH of 2.6, with a Na
5P
3O
10 to indium molar ratio of 0.91, and 1.5
h reaction time. The chemical and X-ray diffraction analyses showed that the main component of the precipitates was NaIn
3 (P
3O
10)
2·12H
2O. The resulting precipitate was dissolved by using NaOH solution and hot sulfuric acid solution respectively, and then the solution was subjected to solvent extraction and cementation using zinc powder for the recovery of indium.
► An attempt was made to develop a new process to precipitate indium from pressure oxidative leaching liquor using sodium tripolyphosphate. ► The temperature has no significant effect on indium precipitation in the range of 25–65 °C. ► The resulting precipitation was dissolved and the solution was subject to solvent extraction and cementation. ► The Indium precipitation percentage was above 95% under optimum conditions and total recovery ratio of indium was more than 95%.
► An uniform Cu–Ni–Fe alloy coating constituted of homogenous γ-phases was prepared on the surface of low-carbon steel. ► The increase of Ni has a significant promotion to produce a uniform and ...homogenous Cu–Ni–Fe alloy coating. ► Electrochemical test results indicated the excellent corrosion resistance of the coating with high Ni content. ► EIS test and results demonstrated the surface homogeneity or compactness of the coating with high Ni content.
In this paper, an attempt had been made to prepare a Cu–Ni–Fe alloy coating for improving the corrosion resistance of the low-carbon steel. The surface heat treatment of coated low-carbon steel was performed at 1000°C for 3h under hydrogen atmosphere. The structure and microstructure of coatings was separately analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The corrosion resistance of the samples was evaluated by potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS). Results indicated that a compact alloy coating was formed on the surface of low-carbon steel and the Ni content had a prodigious impact to the microstructure, composition and structure of Cu–Ni–Fe alloy coating. Apart from that, significant improvements in corrosion resistance were achieved by using the Cu–Ni–Fe alloy coating, which constituting of homogeneous γ-phases.
Cu–Ni–Fe alloy coating was prepared on low-carbon steel by surface alloying. The surface heat treatment of coated low-carbon steel was performed at 700°C, 800°C, 900°C and 1000°C for 3h under ...hydrogen atmosphere. The structure and microstructure of coatings were separately analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A series of electrochemical analysis was carried out to examine the corrosion resistance of Cu–Ni–Fe alloy coatings in borate buffer solution. Results indicated that a uniform and homogeneity Cu–Ni–Fe alloy coating constituted of γ-phases was prepared on the surface of low-carbon steel at 1000°C, which promoted the formation of compact passive film. The passive film significantly improved the substrate's corrosion resistance in alkaline solution.
► Cu–Ni–Fe alloy coating was prepared on low-carbon steel. ► A compact and uniform Cu–Ni–Fe alloy coating constituted of homogeneous γ-phases was prepared at 1000°C ► The Cu–Ni–Fe alloy coating is passive and provides corrosion protection in alkaline solution.
This work introduces the synthesis of smart silica nanoparticles loaded with a corrosion inhibitor (2-mercaptobenzothiazole) and embedded in composite organosilane coatings for corrosion protection ...of carbon steel. Through the BET test, the results show that the mechanically stabilized silica nanoparticles have the characteristics of large specific surface area, narrow pore size distribution and large pore volume. This also provides conditions for sufficient loading of the corrosion inhibitor (CI). Further, smart nano-containers are prepared by encapsulating CI in a layer-by-layer (LBL) self-assembly manner. The anticorrosion properties of the coatings were investigated by electrochemical impedance spectroscopy (EIS) and polarization curve characterization methods. The results indicate that the addition of smart silica nanoparticles can improve the corrosion resistance of the coating. This method simplifies the synthesis process of nanocontainers, which will be widely used in the fabrication of novel nanocontainers and opens up new prospects for active anticorrosion.
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•Smart nanocontainers were fabricated by LBL method.•A self-healing coating is obtained in a simple manner.•The composite silane coating has satisfactory corrosion resistance.
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•A 3D hydrangea-like ZnCo2O4/NiCoGa-layered double hydroxide@polypyrrole core–shell heterostructure was successfully constructed.•Density functional theory (DFT) calculations were ...adopted to authenticate the charge redistribution at the heterointerfaces.•ZnCo2O4/NiCoGa-layered double hydroxide@polypyrrole exhibits satisfactory electrochemical performance for supercapacitors.
Rationally constructing advanced battery-type electrodes with hierarchical core–shell heterostructure is essential for improving the energy density and cycling stability of hybrid supercapacitors. Herein, this work successfully constructs hydrangea-like ZnCo2O4/NiCoGa-layered double hydroxide@polypyrrole (denoted as ZCO/NCG-LDH@PPy) core–shell heterostructure. Specifically, the ZCO/NCG-LDH@PPy employs ZCO nanoneedles clusters with large open void space and rough surfaces as the core, and NCG-LDH@PPy composite as the shell, comprising hexagonal NCG-LDH nanosheets with rich active surface area, and conductive PPy films with different thicknesses. Meanwhile, density functional theory (DFT) calculations authenticate the charge redistribution at the heterointerfaces between ZCO and NCG-LDH phases. Benefiting from the abundant heterointerfaces and synergistic effect among different active components, the ZCO/NCG-LDH@PPy electrode acquires an extraordinary specific capacity of 381.4 mAh g−1 at 1 A g−1, along with excellent cycling stability (89.83% capacity retention) after 10,000 cycles at 20 A g−1. Furthermore, the prepared ZCO/NCG-LDH@PPy//AC hybrid supercapacitor (HSC) exhibits a remarkable energy density (81.9 Wh kg−1), an outstanding power density (17,003.7 W kg−1), and superior cycling performance (a capacitance retention of 88.41% and a coulombic efficiency of 93.97%) at the end of the 10,000th cycle. Finally, two ZCO/NCG-LDH@PPy//AC HSCs in series can light up a LED lamp for 15 min, indicating its excellent application prospects.
The behavior of tannins in complexation with various metal ions was investigated to understand the complexation process of germanium, to reduce tannins use, and to improve the germanium recovery as a ...byproduct in zinc metallurgy. The experimental results obtained show that metal ions with relatively high valence (e.g. Fe
3+) and big ionic radius (e.g. Pb
2+) bind strongly to tannins, and that utilization of the tannins can be improved greatly by re-use and multi-use.
