A facet-controlled Rh 3 Pb 2 S 2 nanocage as an efficient and robust electrocatalyst toward the hydrogen evolution reaction.

Highly active and durable electrocatalysts for the hydrogen evolution reaction (HER) may play a pivotal role in commercial success of electrolytic water splitting technology. Among various material classes, binary metal sulphides show a great promise as HER catalysts because of their tunable energy levels conducive to a high catalytic activity and high robustness under harsh operating conditions. On the other hand, facet-controlled nanoparticles with controlled surface energies have gained great recent popularity as active and selective catalysts. However, binary metal sulphide nanoparticles with well-defined facets and high surface areas are very rare. Herein we report the synthesis of a facet-controlled hollow Rh3Pb2S2 nanocage as a new catalytic material and its excellent activity (overpotential: 87.3 mV at 10 mA cm-2) and robustness toward HER under harsh acidic conditions.