Fluorine-Induced Surface Metallization for Ammonia Synthesis under Photoexcitation up to 1550†nm.

The first observation of surface metallization of TiO2-x induced by fluoride ions is presented. The emerging metallic states are contributed by the 3d orbital of surface Ti and the 2p orbital of surface bridging F, which are intrinsically originated from the strong electron repulsion between F- and adjacent Ti3+ . The metalized TiO2-x with reduced work function and downward band bending possesses high electron-donating power to supported Ru species via atomic-scale ohmic contacts, exhibiting unprecedented photocatalytic performances for ammonia synthesis across the entire solar spectrum region (200-1550 nm) at room temperature. Mechanism and kinetic analysis revealed that the loaded Ru could behave as efficient electron sinks to accumulate photogenerated electrons and that the metallic surface markedly enhanced the dissociation of H2 and N2 by the hot electrons generated by the visible or even infrared light irradiation.

Jumping phase control in interband photonic transition.

Indirect interband photonic transition provides a nonmagnetic and linear scheme to achieve optical isolation in integrated photonics. In this paper, we demonstrate that the nonreciprocal transition can be induced through two pathways respectively by different modulation designs. At the end of those pathways, the two final modes have π phaseshift. We call this phenomenon jumping phase control since this approach provides a method to control the mode phase after the conversion. This approach also yields a novel way to generate nonreciprocal phaseshift and may contribute to chip-scale optoelectronic applications.

Li-intercalated CeO2 as an ideal substrate for boosting ammonia synthesis.

We present a Li-intercalated-CeO2 catalyst that exhibits outstanding activity for ammonia synthesis. The incorporation of Li significantly reduces the activation energy and suppresses hydrogen poisoning of the Ru co-catalysts. As a result, the lithium intercalation enables the catalyst to achieve ammonia production from N2 and H2 at substantially lower operating temperatures.