Category Chemistry/Nanotechnology

The weak electron-donating capability of ruthenium (Ru) nanoparticles supported on niobium pentoxide (Nb2O5) is thought to promote reductive amination while preventing the formation of undesirable by-products. Credit: JACS

Researchers have developed a highly efficient reusable catalyst for the production of primary amines. By cutting the amount of undesired by-products, the catalyst is set to revolutionize the production of bio-based fuels, pharmaceuticals, agricultural chemicals and more. Primary amines (derivatives of ammonia) are industrially important compounds used in the preparation of a wide range of dyes, detergents and medicines...

Phase-Defined van der Waals Schottky Junctions with Significantly Enhanced Thermoelectric Properties. The Journal of Physical Chemistry Letters, 2017; 8 (13): 2887 DOI: 10.1021/acs.jpclett.7b01089

A new device being developed by Washington State University physicist Yi Gu could one day turn the heat generated by a wide array of electronics into a usable fuel source. The device is a multicomponent, multilayered composite material called a van der Waals Schottky diode. It converts heat into electricity up to 3X more efficiently than silicon – a semiconductor material widely used in the electronics industry. While still in an early stage of development, the new diode could eventually provide an extra source of power for everything from smartphones to automobiles.

“The ability of our diode to ...

Scaffolds in a compound solar cell filled with perovskite after fracture testing. Credit: Dauskardt Lab/Stanford University

Packing tiny solar cells together, like micro-lenses in the compound eye of an insect, could pave the way to a new generation of advanced photovoltaics. In a new study, the Stanford team used the insect-inspired design to protect a fragile photovoltaic material, perovskite from deteriorating when exposed to heat, moisture or mechanical stress. The results are published in the journal Energy & Environmental Science (E&ES).

“Perovskites are promising, low-cost materials that convert sunlight to electricity as efficiently as conventional solar cells made of silicon,” said Reinhold Dauskardt, a professor of materials science and engineering and senior author of the study...

Schematic of the epitaxial growth procedure of ZnSe/GaAs heterostructure growth using either light-start or dark-start growth procedures. (a) Prior to ZnSe epilayer growth, the GaAs epilayer was grown in a dedicated III-V MBE chamber and was covered with an amorphous arsenic film prior to transferring it to a dedicated II-VI chamber. (b) The amorphous arsenic film was then thermally desorbed and the interface growth was initiated with a Zn pre-treatment under either a light-start or dark-start condition. During light-start sample growth, UV light was directed onto the growth surface from the beginning of Zn pre-treatment until the end of the ZnSe growth (f–h). During dark-start sample growth, UV light was directed onto the growth surface only during ZnSe epilayer growth (c–e).

A discov...