Yongye Liang

Advanced materials for electrocatalytic and photoelectrochemical water splitting are central to the area of renewable energy. In this work, we developed a selective solvothermal synthesis of MoS(2) nanoparticles on reduced graphene oxide (RGO) sheets suspended in solution. The resulting MoS(2)/RGO hybrid material possessed nanoscopic few-layer MoS(2) structures with an abundance of exposed edges stacked onto graphene, in strong contrast to large aggregated MoS(2) particles grown freely in solution without GO. The MoS(2)/RGO hybrid exhibited superior electrocatalytic activity in the hydrogen evolution reaction (HER) relative to other MoS(2) catalysts. A Tafel slope of ∼41 mV/decade was measured for MoS(2) catalysts in the HER for the first time; this exceeds by far the activity of previous MoS(2) catalysts and results from the abundance of catalytic edge sites on the MoS(2) nanoparticles and the excellent electrical coupling to the underlying graphene network. The ∼41 mV/decade Tafel slope suggested the Volmer-Heyrovsky mechanism for the MoS(2)-catalyzed HER, with electrochemical desorption of hydrogen as the rate-limiting step.

The photovoltaic performance of polymer bulk heterojunction solar cells is studied systematically. Using a new benzodithiophene polymer (PTB7) and PC71BM (see figure) a power conversion efficiency of 7.4% has been achieved in PTB7/PC71BM-blend film, indicating a great potential and bright future for polymer solar cells (FF = fill factor, PCE ;= power-conversion efficiency). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Highly active, durable, and cost-effective electrocatalysts for water oxidation to evolve oxygen gas hold a key to a range of renewable energy solutions, including water-splitting and rechargeable metal-air batteries. Here, we report the synthesis of ultrathin nickel-iron layered double hydroxide (NiFe-LDH) nanoplates on mildly oxidized multiwalled carbon nanotubes (CNTs). Incorporation of Fe into the nickel hydroxide induced the formation of NiFe-LDH. The crystalline NiFe-LDH phase in nanoplate form is found to be highly active for oxygen evolution reaction in alkaline solutions. For NiFe-LDH grown on a network of CNTs, the resulting NiFe-LDH/CNT complex exhibits higher electrocatalytic activity and stability for oxygen evolution than commercial precious metal Ir catalysts.