Thursday, November 12, 2015: 10:10 AM
355C (Salt Palace Convention Center)
A novel organic solvothermal approach is developed for the synthesis of ultrathin molybdenum disulfide (MoS2) nanosheets. By coupling the thermal decomposition of molybdenum carbonyl and sulfurization with element sulfur, MoS2 nanosheets of a few (<3) layers thick were obtained via preferential in-plane growth. The in-plane size of the nanosheets is tunable in the range of <5 to 20 nm by controlling the growth time. Thermal treatments were applied to remove the organic surfactant and manipulate the stacking along c axis from <3 to ~10 molecular layers without causing significant agglomeration in-plane. The treated nanosheets possess enhanced electrocatalytic activity for the hydrogen evolution reaction (HER), with an improvement factor of ~3 compared to commercial MoS2. The electrochemical studies further show size- and stacking-dependent catalytic activities, which can be ascribed to the edge sites being as active sites and likely also a molecular hindrance mechanism.