Powder metallurgy is important in material preparation. Due to the inertness of carbon materials, however, sintering powdered carbon into physically coherent bulks has been a great challenge even at a high temperature (2000 ℃). Improving the sintering activity of carbon powders is the key to the success of the consolidation of the carbon powders. Here ordered mesoporous carbon (OMC) is used as the starting material to produce highly homogeneous novel carbon bulks. During sintering at 1800 ℃, the huge specific surface area of the OMC greatly promotes the migration of carbon atoms and thus the sintering of the OMC by surface diffusion mechanism. When nanodiamond (ND) is added, the volume expansion associated with the phase transformation of diamond to graphite facilitates the densification of the powder compacts. The strong connection between the OMC and the graphite onions derived from the ND bestows the as-prepared carbon bulks with excellent mechanical properties. The current research pioneers a novel way to prepare high-strength carbon materials at relatively low temperatures.

As a semiconducting material with relatively low thermal conductivity, MoS₂ nanoflake has the potential to serve as a modulator for optimizing the performance of thermoelectric (TE) materials. However, the low yield of MoS₂ nanoflakes prepared by conventional methods has constrained the development of MoS₂ optimized TE materials. We propose a mechanical exfoliation method for mass production of MoS₂ nanoflakes using attrition mill. After mixed with La and Nb co-doped SrTiO₃ (SLNT) powder, the MoS₂/SLNT composites are fabricated by spark plasma sintering. It is found that the heterojunctions formed at MoS₂/SLNT interfaces with proper band offset can effectively scatter the low-energy electrons, resulting in enhanced Seebeck coefficient without significantly undermining the electrical conductivity. The power factor of composites is improved when the MoS₂ content is lower than 1.5 vol%. Meanwhile, the thermal conductivity of composites is significantly decreased due to the phonon scattering induced large thermal resistance at MoS₂/SLNT interfaces, which is much higher than that in graphene embedded SrTiO₃ composites. Consequently, a maximum ZT = 0.24 is obtained at 800 K in 1.5 vol% MoS₂/SLNT composite, which is ~26 % higher compared with pristine matrix. This work paves the way for application of TE materials modulated by transition metal dichalcogenides.