• carbon nitride;   • hydrogen evolution reaction;   •
nanoparticles;   • tungsten carbide;   • water splitting
Tungsten carbide exhibits platinum-like behavior, which makes it
an interesting potential substitute for noble metals in
catalytic applications. Tungsten carbide nanocrystals (≈5 nm)
are directly synthesized through the reaction of tungsten
precursors with mesoporous graphitic C3N4 (mpg-C3N4) as the
reactive template in a flow of inert gas at high temperatures.
Systematic experiments that vary the precursor compositions and
temperatures used in the synthesis selectively generate
different compositions and structures for the final nanocarbide
(W2C or WC) products. Electrochemical measurements demonstrate
that the WC phase with a high surface area exhibits both high
activity and stability in hydrogen evolution over a wide pH
range. The WC sample also shows excellent hydrogen oxidation
activity, whereas its activity in oxygen reduction is poor.
These tungsten carbides are successful cocatalysts for o