Source Metalorganic Chemical Vapor Research Articles

Bifunctional metal phosphide FeMnP films from single source metal organic chemical vapor deposition for efficient overall water splitting

Developing stable and efficient bifunctional catalysts for overall water splitting into hydrogen and oxygen is a critical step in the realization of several clean-energy technologies. Here we report a robust and highly active electrocatalyst that is constructed by deposition of the ternary metal phosphide FeMnP onto graphene-protected nickel foam by metal-organic chemical vapor deposition from a single source precursor. FeMnP exhibits high electrocatalytic activity toward both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Utilizing FeMnP/GNF as both the anode and the cathode for overall water splitting, a current density of 10mAcm−2 is achieved at a cell voltage of as low as 1.55V with excellent stability. Complementary density functional theory (DFT) calculations suggest that facets exposing both Fe and Mn sites are necessary to achieve high HER activity. The present work provides a facile strategy for fabricating highly efficient electrocatalysts from earth-abundant materials for overall water splitting.

Chemical vapor deposition and structural study of La 0.8 MnO 3− δ thin films

We report here the synthesis of lacunar lanthanum manganites La 0.8MnO 3− δ by a liquid source metal organic chemical vapor deposition technique which has been developed recently in our laboratory. The role of the substrate temperature on the growth rate, on the molar ratio La/Mn and on the crystallinity is studied for films deposited on MgO (001) single crystals. A structural study by means of X-ray diffraction ( θ/2 θ scans, ω-scans, ϕ-scans) and scanning electron microscopy (channeling electron patterns) has been achieved on lanthanum manganites films with the composition La 0.8MnO 3− δ grown on three kinds of substrates: MgO (001), LaAlO 3 (012) and SrTiO 3 (001). Films on LaAlO 3 and SrTiO 3 show an epitaxial quality with a small mosaicity in the plane of the substrate. Due to a bigger lattice mismatch with the substrate, films deposited on MgO present a worse crystalline quality with two types of epitaxially grown crystallites.