Thiomolybdate [Mo3S13]2- Nanoclusters Anchored on Reduced Graphene Oxide-Carbon Nanotube Aerogels for Efficient Electrocatalytic Hydrogen Evolution

Thiomolybdate [Mo3S13](2-) nanoclusters anchored on reduced graphene oxide-carbon nanotube (rGO-CNTs) aerogels were used as a new catalyst for efficient electrocatalytic hydrogen evolution. The elemental distribution of sulfur (S) corresponded well to the Mo distribution, and both Mo and S elements distributed evenly in the Mo3S13@rGO-CNTs aerogels. Results indicated that [Mo3S13](2-) nanoclusters inherently exposed a high number of active edge sites, which greatly improved the electrocatalytic hydrogen evolution. The new peak at 168.8 eV corresponded to the characteristic S-O binding in the S 2p region of Mo3S13@rGO-CNTs, indicating that the [Mo3S13](2-) clusters were bond onto the rGO-CNTs aerogels through S-O binding. The strong support of rGO-CNTs aerogels suppressed the aggregation of [Mo3S13](2-) nanoclusters, exposing more active surface and electrons diffusions on the surface of Mo3S13@rGO-CNTs aerogels. Mo3S13@rGO-CNTs aerogels laden with 20 mg of [Mo3S13](2-) exhibited close hydrogen evolution reaction (HER) performance as compared with that of [Mo3S13-120]@rGO-CNTs aerogels laden with 120 mg of [Mo3S13](2-) nanoclusters. This indicated the extremely high HER performance of [Mo3S13](2-) even at low mass. As a result, Mo3S13@rGO-CNTs aerogels enabled remarkable electrochemical performances showing a low overpotential (0.179 V at 10 mA cm(-2)) with a small Tafel slope, reduced transfer resistance, and excellent stability.