2 research outputs found

    Synergetic Effect of MoS<sub>2</sub> and Graphene as Cocatalysts for Enhanced Photocatalytic H<sub>2</sub> Production Activity of TiO<sub>2</sub> Nanoparticles

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    The production of H<sub>2</sub> by photocatalytic water splitting has attracted a lot attention as a clean and renewable solar H<sub>2</sub> generation system. Despite tremendous efforts, the present great challenge in materials science is to develop highly active photocatalysts for splitting of water at low cost. Here we report a new composite material consisting of TiO<sub>2</sub> nanocrystals grown in the presence of a layered MoS<sub>2</sub>/graphene hybrid as a high-performance photocatalyst for H<sub>2</sub> evolution. This composite material was prepared by a two-step simple hydrothermal process using sodium molybdate, thiourea, and graphene oxide as precursors of the MoS<sub>2</sub>/graphene hybrid and tetrabutylorthotitanate as the titanium precursor. Even without a noble-metal cocatalyst, the TiO<sub>2</sub>/MoS<sub>2</sub>/graphene composite reaches a high H<sub>2</sub> production rate of 165.3 μmol h<sup>–1</sup> when the content of the MoS<sub>2</sub>/graphene cocatalyst is 0.5 wt % and the content of graphene in this cocatalyst is 5.0 wt %, and the apparent quantum efficiency reaches 9.7% at 365 nm. This unusual photocatalytic activity arises from the positive synergetic effect between the MoS<sub>2</sub> and graphene components in this hybrid cocatalyst, which serve as an electron collector and a source of active adsorption sites, respectively. This study presents an inexpensive photocatalyst for energy conversion to achieve highly efficient H<sub>2</sub> evolution without noble metals

    Fabrication of Heterostructured Metal Oxide/TiO<sub>2</sub> Nanotube Arrays Prepared via Thermal Decomposition and Crystallization

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    Heterostructured TiO<sub>2</sub> materials are of great importance in electronic and photochemical related applications. We report herein a simple, low-cost, and scalable fabrication of metal oxides heterostructured TiO<sub>2</sub> nanotube arrays (NTAs) through a combined strategy of thermal decomposition and crystallization. Various M<sub><i>x</i></sub>O<sub><i>y</i></sub>/TiO<sub>2</sub> heterostructured films (M = Zn, Ce, Cu, Cr...) were obtained by using TiO<sub>2</sub> NTAs as “nano-containers” as well as “nano-reactors”, while using M­(CH<sub>3</sub>­COO)<sub><i>x</i></sub> solutions as the precursors. SEM, XRD, EDS results demonstrated that Cu<sub>2</sub>O/TiO<sub>2</sub> NTAs, ZnO/TiO<sub>2</sub> NTAs, Cr<sub>2</sub>O<sub>3</sub>/TiO<sub>2</sub> NTAs, and CeO<sub>2</sub>/TiO<sub>2</sub> NTAs were successfully fabricated. Photocatalytic results revealed that the heterostructured M<sub><i>x</i></sub>O<sub><i>y</i></sub>/TiO<sub>2</sub> films could either enhance the UV photocatalytic activities or enable the visible light photocatalytic activities of the TiO<sub>2</sub> NTAs. This study provides a facile general approach to prepare M<sub><i>x</i></sub>O<sub><i>y</i></sub>/TiO<sub>2</sub> NTAs films, which could be very useful for environmental and energy areas