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TiC/Al–Cu nanocomposites were fabricated in Al–Ti–C powder systems using carbon black, a mixture of C and carbon nanotubes (C + CNTs), and CNTs via an in-situ method involving combustion synthesis and hot pressing. As the carbon source changed from pure carbon black to the C + CNT mixture and pure CNTs, the size of the TiC nanoparticles decreased gradually. The nanocomposites synthesized based on the C + CNT mixture exhibited the most uniform dispersion of TiC nanoparticles. The 30 vol% TiC/Al–Cu nanocomposite prepared from the C + CNT mixture had the best comprehensive mechanical properties (yield strength (411 MPa), compressive strength (712 MPa), fracture strain (17.2%), hardness (206.8 HV), and wear resistance under the experimental conditions due to having the most uniformly dispersed TiC nanoparticles. The wear mechanism was a combination of plastic deformation, abrasion, and adhesion. This method may be a low-cost and convenient means to control the sizes of in-situ TiC nanoparticles and prepare high-performance TiC/Al–Cu nanocomposites. [ABSTRACT FROM AUTHOR]

As an energy storage device, Zn–air battery has great market prospects due to its relatively high theoretical energy density, low cost, safe and reliable performances. Since the cathodic oxygen reduction reaction (ORR) is a sluggish kinetic process, efficient electrocatalysts are essential to facilitate the ORR. Herein, we report the one-step synthesis of non-precious metals loaded C–N tubular nanocomposites via the pyrolysis of the mixture composed of dicyandiamide (DCD), Co/Ni acetates, ethylenediamine, and different organic carbon sources like soluble starch(st), β-cyclodextrin(cyc) and carbon black(cb). The prepared nanocomposites present a hollow tubular structure, and the Co/Ni nanoparticles are uniformly distributed on the CN nanotubes. In the prepared catalysts, Co3Ni2/CN(st) exhibits excellent ORR electroactivity close to the Pt/C catalyst in the alkaline medium. An alkaline Zn–air battery is assembled by using the Co3Ni2/CN(st) as the cathodic electrocatalyst. The open-circuit voltage reaches 1.51 V in 6 mol L−1 KOH electrolyte and the maximum power density reaches 331 mW cm−2. At different discharging current densities, the Co3Ni2/CN(st) battery exhibits stable and higher voltage plateaus than the Pt/C battery. The battery can discharge continuously for up to 80 and 51 h, corresponding to the constant discharge current density of 50 and 100 mA cm−2, respectively. The results show that the Co3Ni2/C–N(st) catalyst has potential application prospects as an excellent cathodic material for alkaline Zn–air batteries. CoNi loaded C–N tubular nanocomposites with well-defined hollow tubular structure, synthesized by one-step pyrolyzing the mixture of cobalt//nickel salts, dicyandiamide (DCD) and different carbon sources including soluble starch(st), β-cyclodextrin(cyc) and carbon black(cb), present superior performance as the cathodic catalysts of alkaline Zn–air batteries. [ABSTRACT FROM AUTHOR]