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Manganese phosphate coating could be used to protect the surface of steel products. However, it is essential to determine the effects which process parameters, as well as the types of additives used, have on the efficiency of coating deposition. Thus, we present here a process of phosphatization of low-alloy steel (for 15 min at 95 °C) in manganese/nickel baths followed by a passivation process with the use of a silicon and zircon compounds. The microstructure and morphology of the surface were analyzed by SEM EDX and XRD methods. The obtained results showed that the manganese phosphate could be effectively formed at 95 °C in the solution containing nickel and guanidine derivatives. Anodic polarization of manganese coating was investigated in 0.5 M KCl by the analysis of polarization resistance. The effects of the activation process on corrosion properties of the coating have been examined. It was observed that an increased concentration of activating substances in the activation bath results in the enhancement of corrosion resistance.

Conversion coatings are one of the primary types of galvanic coatings used to protect steel structures against corrosion. They are created through chemical reactions between the metal surface and the environment of the phosphating. This paper investigates the impact that the addition of new metal cations to the phosphating reaction environment has on the quality of the final coating. So far, standard phosphate coatings have contained only one primary element, such as zinc in the case of zinc coatings, or two elements, such as manganese and iron in the case of manganese coatings. The structural properties have been determined using a scanning electron microscope (SEM), X-ray diffraction (XRD), and electrochemical tests. New manganese coatings were produced through a reaction between the modified phosphating bath and the metal (Ba, Zn, Cd, Mo, Cu, Ce, Sr, and Ca). This change was noticeable in the structure of the produced manganese phosphate crystallites. A destructive effect of molybdenum and chromium was demonstrated. Microscopic analysis, XRD analysis and electrochemical tests suggest that the addition of new metal cations to the phosphating bath affects the corrosion resistance of the modified coating.

In situ formation of a stable interphase layer on zinc surface is an effective solution to suppress dendrite growth. However, the fast transport of bivalent Zn-ions within the solid interlayer remains very challenging. Herein, we engineer the SEI components and enable superior kinetics of Zn metal batteries under harsh conditions through regulating the sequence of interfacial chemical reaction. With the differences in chemical reactivity of trimethyl phosphate co-solvent and trifluoromethanesulfonate anions in the Zn 2+ -solvation shell, Zn 3 (PO 4 ) 2 and ZnF 2 are successively generated on Zn metal surface to form a gradient ZnF 2 –Zn 3 (PO 4 ) 2 interphase. Mechanistic studies reveal the outer ZnF 2 facilitates Zn 2+ desolvation and inner Zn 3 (PO 4 ) 2 serves as channels for fast Zn 2+ transport, contributing to long-term cycling at subzero temperatures. Impressively, the gradient SEI enables a high lifespan over 7000 hours in Zn symmetric cell and a capacity retention of 86.1% after 12000 cycles in Zn–KVOH full cell at –50 °C. Zinc batteries have received intense attentions but suffer from inferior low-temperature performance. Here, the authors constructed a gradient phosphatized interphase in situ on zinc surface to accelerate zinc-ion desolvation and transport, greatly enhancing the cycling performance at subzero temperatures.

Operating the dry reforming reaction photocatalytically presents an opportunity to produce commodity chemicals from two greenhouse gases, carbon dioxide and methane, however, the top-performing photocatalysts presented in the academic literature invariably rely on the use of precious metals. In this work, we demonstrate enhanced photocatalytic dry reforming performance through surface basicity modulation of a Ni-CeO 2 photocatalyst by selectively phosphating the surface of the CeO 2 nanorod support. An optimum phosphate content is observed, which leads to little photoactivity loss and carbon deposition over a 50-hour reaction period. The enhanced activity is attributed to the Lewis basic properties of the PO 4 3− groups which improve CO 2 adsorption and facilitate the formation of small nickel metal clusters on the support surface, as well as the mechanical stability of CePO 4 . A hybrid photochemical-photothermal reaction mechanism is demonstrated by analyzing the wavelength-dependent photocatalytic activities. The activities, turnover numbers, quantum efficiencies, and energy efficiencies are shown to be on par with other dry-reforming photocatalysts that use noble metals, representing a step forward in understanding how to stabilize ignoble nickel-based dry reforming photocatalysts. The challenges associated with comparing the performance of photocatalysts reported in the academic literature are also commented on. The top-performing dry reforming photocatalysts in the literature rely on the use of precious metals. Here, enhanced photocatalytic dry reforming performance is reported through surface basicity modulation of a Ni/CeO 2 photocatalyst, achieved by selectively phosphating the surface of a CeO 2 nanorod support.

Transition metal phosphides (TMPs) are promising candidates for noble metal free electrocatalysts in water splitting applications. In this work, we present the facile synthesis of nickel cobalt phosphide electrocatalyst with three-dimensional nanostructure (3D-NiCoP) on the nickel foam, via hydrothermal reaction and phosphorization. The as-prepared electrocatalyst exhibits an excellent activity for hydrogen evolution reaction (HER) in both acidic and alkaline electrolytes, with small overpotentials to drive 10 mA/cm 2 (80 mV for 0.5 M H 2 SO 4 , 105 mV for 1 M KOH), small Tafel slopes (37 mV/dec for 0.5 M H 2 SO 4 , 79 mV/dec for 1 M KOH), and satisfying durability in long-term electrolysis. 3D-NiCoP also shows a superior HER activity compared to single metal phosphide, such as cobalt phosphide and nickel phosphide. The outstanding performance for HER suggests the great potential of 3D-NiCoP as a highly efficient electrocatalyst for water splitting technology.

Exploring bifunctional catalysts for the hydrogen and oxygen evolution reactions （HER and OER） with high efficiency, low cost, and easy integration is extremely crucial for future renewable energy systems. Herein, ternary NiCoP nanosheet arrays （NSAs） were fabricated on 3D Ni foam by a facile hydrothermal method followed by phosphorization. These arrays serve as bifunctional alkaline catalysts, exhibiting excellent electrocatalytic performance and good working stability for both the HER and OER. The overpotentials of the NiCoP NSA electrode required to drive a current density of 50 mA/cm2 for the HER and OER are as low as 133 and 308 mV, respectively, which is ascribed to excellent intrinsic electrocatalytic activity, fast electron transport, and a unique superaerophobic structure. When NiCoP was integrated as both anodic and cathodic material, the electrolyzer required a potential as low as -1.77 V to drive a current density of 50 mA/cm2 for overall water splitting, which is much smaller than a reported electrolyzer using the same kind of phosphide-based material and is even better than the combination of Pt/C and Ir/C, the best known noble metal-based electrodes. Combining satisfactory working stability and high activity, this NiCoP electrode paves the way for exploring overall water splitting catalysts.

The optimization study of the phosphating process was conducted on the surface of ZK21 biomedical magnesium alloy using the chemical conversion technique to fabricate Ca-P coating. The findings reveal that the optimal concentrations of the three additives in the phosphating solution, Ca(CH 3 COO) 2 , C 6 H 4 O 5 NSNa, and Na 2 MoO 4 , are 12 g/L, 2 g/L, and 0.5 g/L, respectively. Under these specified conditions, the resulting Ca-P coating appears compact and uniform. An optimal quantity of Ca(CH 3 COO) 2 can enhance the concentration of Ca 2 + in the solution. C 6 H 4 O 5 NSNa accelerates the rate of membrane formation, whereas Na 2 MoO 4 facilitates the creation of nucleation sites, consequently bolstering membrane formation even further. Analysis through EDS and XRD confirmed that the predominant compound in the Ca-P coating is CaPO 3 (OH) 2 ·2H 2 O (DCPD).

Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). In this study, a method was developed to synthesize directly porous Ni 2 P nanosheet arrays and Ni 2 P nanoparticles onto nickel foam via a hydrothermal reaction followed by a phosphorization process. Mechanistic studies revealed that the allomorphs of Ni 2 P nanosheets and Ni 2 P nanoparticles in the array-like structure were formed via the Kirkendall effect and Ostwald ripening. A fully functional water electrolyzer containing Ni 2 P as electrodes for the OER and HER exhibited promising activity and stability. At 10 mA·cm −2 , a Ni 2 P cell voltage of 1.63 V was obtained, which was only 0.05 V smaller than that found for Pt/C/NF||RuO 2 /NF cell. The enhanced electrocatalytic performance resulted from the favorable porosity of the Ni 2 P arrays and the synergistic effect between Ni 2 P nanosheets and Ni 2 P nanoparticles.

The urea oxidation reaction has attracted increasing attention. Here, porous rod-like Ni 2 P/Ni assemblies, which consist of numerous nanoparticle subunits with matching interfaces at the nanoscale have been synthesized via a simple phosphating approach. Density functional theory calculations and density of states indicate that porous rod-like Ni 2 P/Ni assemblies can significantly enhance the activity of chemical bonds and the conductivity compared with NiO/Ni toward the urea oxidation reaction. The optimal catalyst of Ni 2 P/Ni can deliver a low overpotential of 50 mV at 10 mA·cm −2 and Tafel slope of 87.6 mV·dec −1 in urea oxidation reaction. Moreover, the constructed electrolytic cell exhibits a current density of 10 mA·cm −2 at a cell voltage of 1.47 V and an outstanding durability in the two-electrode system. This work has provided a new possibility to fabricate metal phosphides-metal assemblies with advanced performance.

In this study, nickel cobalt phosphate ((Ni,Co)(PO 4 ) 3 ) has been developed as a positive electrode in supercapacitors. (Ni,Co)(PO 4 ) 3 is synthesized through a phosphorization and carbonization method using NiCo glycerate as a precursor combined with triethyl phosphate (TEP), subsequently an annealing process at 600°C under air conditions. The choice of solvent like hexanol has a significant influences on the morphology of nickel cobalt phosphate ((Ni,Co)(PO 4 ) 3 ), leading to the formation of cracker-like structures. Additionally, the resulting product exhibits an amorphous phase, indicating the absence of a well-defined crystalline arrangement. The electrochemical performance evaluation shows the peak from oxidation and reduction reactions at scan rate 5 mVs −1 until 100 mVs −1 . Following that the specific capacitance reaches 743 Fg −1 at current density 1 Ag −1 .