Single-source-precursor synthesis of porous W-containing SiC-based nanocomposites as hydrogen evolution reaction electrocatalysts

In this paper, W-containing SiC-based ceramic nanocomposites were successfully prepared by a polymer-derived ceramic approach using allylhydridopolycarbosilane (AHPCS) as a SiC source, WCl6 as a tungsten source, polystyrene (PS) as a pore forming agent as well as divinyl benzene (DVB) as a carbon rich source. High-temperature phase behavior of the W-containing SiC-based ceramics after heat treatment was studied, showing that excessive DVB content in the feed will inhibit the crystallinity of W-containing nanoparticles in the final ceramic nanocomposites. The high specific surface area (SSA) of 169.4-276.9 m(2)/g can be maintained even at high temperature in the range of 1400-1500 degrees C, due to the carbothermal reaction which usually occurs between 1300 and 1400 degrees C. All prepared W-containing SiC-based nanocomposites reveal electrocatalytic activity for the hydrogen evolution reaction (HER). In detail, compared with reversible hydrogen electrode (RHE), the ceramic sample PWA-2-1300 after heat treatment at 1300 degrees C has the smallest overpotential of 286 mV when the current density is 10 mA center dot cm(-2) in acid medium, indicating the promising perspective in the water splitting field.

Automated summary

In this study, W-containing SiC-based ceramic nanocomposites were prepared using a polymer-derived ceramic approach. The high-temperature phase behavior was studied, showing that excessive carbon source in the feed will inhibit the crystallinity of nanoparticles. The nanocomposites maintained high specific surface area even at high temperatures and exhibited electrocatalytic activity for the hydrogen evolution reaction.