Wuhan University of Technology

About: Wuhan University of Technology is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Microstructure & Photocatalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

MoB/g-C3N4 Interface Materials as a Schottky Catalyst to Boost Hydrogen Evolution

Abstract: Proton adsorption on metallic catalysts is a prerequisite for efficient hydrogen evolution reaction (HER). However, tuning proton adsorption without perturbing metallicity remains a challenge. A Schottky catalyst based on metal–semiconductor junction principles is presented. With metallic MoB, the introduction of n-type semiconductive g-C3N4 induces a vigorous charge transfer across the MoB/g-C3N4 Schottky junction, and increases the local electron density in MoB surface, confirmed by multiple spectroscopic techniques. This Schottky catalyst exhibits a superior HER activity with a low Tafel slope of 46 mV dec−1 and a high exchange current density of 17 μA cm−2, which is far better than that of pristine MoB. First-principle calculations reveal that the Schottky contact dramatically lowers the kinetic barriers of both proton adsorption and reduction coordinates, therefore benefiting surface hydrogen generation.

Phase segregation enhanced ion movement in efficient inorganic CsPbIBr2 solar cells

Abstract: Organic–inorganic hybrid perovskite solar cells with mixed cations and mixed halides have achieved impressive power conversion efficiency of up to 22.1%. Phase segregation due to the mixed compositions has attracted wide concerns, and their nature and origin are still unclear. Some very useful analytical techniques are controversial in microstructural and chemical analyses due to electron beam-induced damage to the “soft” hybrid perovskite materials. In this study photoluminescence, cathodoluminescence, and transmission electron microscopy are used to study charge carrier recombination and retrieve crystallographic and compositional information for all-inorganic CsPbIBr2 films on the nanoscale. It is found that under light and electron beam illumination, “iodide-rich” CsPbI(1+x)Br(2−x) phases form at grain boundaries as well as segregate as clusters inside the film. Phase segregation generates a high density of mobile ions moving along grain boundaries as ion migration “highways.” Finally, these mobile ions can pile up at the perovskite/TiO2 interface resulting in formation of larger injection barriers, hampering electron extraction and leading to strong current density–voltage hysteresis in the polycrystalline perovskite solar cells. This explains why the planar CsPbIBr2 solar cells exhibit significant hysteresis in efficiency measurements, showing an efficiency of up to 8.02% in the reverse scan and a reduced efficiency of 4.02% in the forward scan, and giving a stabilized efficiency of 6.07%.