Cobalt phosphides

Cobalt Phosphides.—The phosphides of this metal are produced by... 

Figure 30 shows thermodynamic data for several cobalt phosphides under various P4 partial pressures (31). Cobalt phosphide C0P3 reduces in the following three steps ... 

Fig. 30. Thermodynamic equilibrium data of several cobalt phosphides under various partial pressures. Curves 1, 2, and 3 refer to C0P2, CoP, and C02P, respectively [reprinted with permission from Mangnus et al. 3iy, copyright 1990 Elsevier Science].

At higher temperatures, the influence of phosphorus on the sulfidation of the promotors is completely different. Mangnus et al. 70) reported that the temperature required to obtain complete sulfidation of cobalt in Co—P/Al increases with increasing phosphorus content. The S/Co atomic ratio after sulfidation at 1000°C decreases from 1.3 to 0.39 as a result of phosphorus addition because of the formation of nonsulfided compounds such as cobalt phosphides, according to the following reactions ... 

Figure 32 represents the relative amount of cobalt present as cobalt phosphides as a function of the phosphorus content. 

Cobalt phosphide CO3P 12134-02-0 148.840 gray needles 1386 6.4 iH,0 sHN0,... 

Palladium phosphide, PdjP, for example, can have any composition in the range PdjPojs- PdsP,, 00 and cobalt phosphide, Co2Pin the range CO175P-CO2.00P These phenomena are believed to be associated with vacant lattice sites where P or metal atoms are missing. Both boron and silicon have appreciable solid solution in some metal phosphides, where random substitution for P atoms occurs (Table 8.6). 

Magnetic semiconducting materials have also been explored cobalt phosphide (C02P) nanowires have been synthesised by a one-pot colloidal reaction of cobalt oleate in TOP at 290 or 320 °C [Fig. 14(a),(b)]. Initially, cobalt (II) carbonate reaeted with oleic acid at 80 °C in TOP to form cobalt (II) oleate which was further heated up to obtain cobalt phosphide nanostructures. When OAm was added to the reaction pot at 290 or 320 °C, C02P or CoP nanorods were formed respectively [Fig. 14(c),(d)]. The erystallite size of the nanowires (5.6 and 6.6 nm) and nanorods (8.7 and 14 nm) increased with reaction temperature according to XRD analysis. Ternary cobalt iron phosphide nanostructures were synthesised by the reaction of iron (III) oleate and cobalt (II) oleate with TOP in the presence of OAm. Coi.sFeo.sP nanorice was obtained at 290 °C, whereas C01.7Feo.3P parallel/ perpendicular split nanostructures was formed at 320 °C [Fig. 14(e),(f)]. 

Single-source precursors were also employed for the growth of cobalt phosphide materials. C02P or CoP nanoparticles (ca. 5 nm) were obtained by the injection of cobalt diselenophosphinate [Co(Sc2PR2)2] (R = Pr, Ph and Bu) precursor dissolved in TOP to TOPO or HDA at 300 °C after 60 and 150 minutes respectively. Similarly, thermal decomposition of the dithio... 

Cao S, Chen Y, Hou C-C, Lv X-J, Fu W-F (2015) Cobalt phosphide as a highly active non-precious metal cocatalyst for photocatalytic hydrogen production under visible light irradiation. J Mater Chem A 3 6096-6101... 

The reactivity of metal phosphide cations [MPJ+, and anions [MPJ , may also be studied in the gas phase. Laser ablation of mixtures of cobalt or nickel metal powders with red phosphorus gave a range of anions M PJ and cations [MPJ+ (185). The anions were unreactive, but the cations have been reacted with several neutral molecules. The ions [MPJ+, where M = Co, Ni and x = 2,4, 8, undergo five types of reactions. 

Phosphorus unites with most of the metals, forming phosphides. Phosphorus is electronegative towards hydrogen, and its affinity for the metals is rather less than that of sulphur. The phosphides are made by the direct union of the two elements usually assisted by heat, and in an atmosphere of an inert gas to prevent undue oxidation. In this way, at a dull red-heat, the metals iron, nickel, cobalt, copper, manganese, palladium, platinum, and iridium united with phosphorus with incandescence and gold, silver, tin, and zinc without incandescence. Phosphides VOL. VIII. 3 B... 

The phosphides, arsenides, and antimonides of the other metals are usually dark-coloured substances, with more or less metallic lustre, and therefore conductors of electricity. Some of them occur native for example, smaltine, CoAs2, a common ore of cobalt, forming silver-white crystals copper-nickel, NiAs, red lustrous crystals, and one of the chief nickel ores speiss, a deposit formed in the pots in which smaltine and copper-nickel are fused with potassium carbonate and silica, in the preparation of smalt, a blue glass containing cobalt its formula appears to be Ni8As2. Mispickel, or arsenical pyrites, is a white lustrous substance, of the formula FeSAs. 

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