Interfacial Electronic Effects in Co@N-Doped Carbon Shells Heterojunction Catalyst for Semi-Hydrogenation of Phenylacetylene

Metal-supported catalyst with high activity and relatively simple preparation method is given priority to industrial production. In this work, this study reported an easily accessible synthesis strategy to prepare Mott-Schottky-type N-doped carbon encapsulated metallic Co (Co@Np+gC) catalyst by high-temperature pyrolysis method in which carbon nitride (g-C3N4) and dopamine were used as support and nitrogen source. The prepared Co@Np+gC presented a Mott-Schottky effect; that is, a strong electronic interaction of metallic Co and N-doped carbon shell was constructed to lead to the generation of Mott-Schottky contact. The metallic Co, due to high work function as compared to that of N-doped carbon, transferred electrons to the N-doped outer shell, forming a new contact interface. In this interface area, the positive and negative charges were redistributed, and the catalytic hydrogenation mainly occurred in the area of active charges. The Co@Np+gC catalyst showed excellent catalytic activity in the hydrogenation of phenylacetylene to styrene, and the selectivity of styrene reached 82.4%, much higher than those of reference catalysts. The reason for the promoted semi-hydrogenation of phenylacetylene was attributed to the electron transfer of metallic Co, as it was caused by N doping on carbon.

Improving the electrical properties of TiOx Schottky-type diode with an extra ZrO2 insulating layer

Titanium oxide has been considered a promising candidate for Schottky-type diode application. In this paper, an alternative approach for improving electrical properties of TiO[Formula: see text]-based Schottky-type diode has been demonstrated. Compared with the Ag/TiO[Formula: see text]/Ti structure Schottky-type diode, by embedding an extra ZrO2 insulating layer between the Ag/TiO[Formula: see text] interface, an extremely high rectifying ratio of 109 can be obtained in the Ag/ZrO2/TiO[Formula: see text]/Ti structure device. The improvement of the electrical properties in the Ag/ZrO2/TiO[Formula: see text]/Ti structure device can be attributed to the localized formation of Ag metal conductive filaments in ZrO2 layer after switching on.