Category Chemistry/Nanotechnology

The silicon-tin nanocomposite developed at UCR viewed by high angle angular dark field imaging. The larger green particles are silicon and the smaller red particles are tin. Credit: UC Riverside

A new silicon-tin nanocomposite anode could lead to lithium-ion batteries that can be charged and discharged more times before they reach the end of their useful lives. The longer-lasting batteries could be used in everything from handheld electronic devices to electric vehicles.

Lithium-ion batteries, the most popular rechargeable batteries in personal electronics, are composed of 3 main parts: an anode, a cathode, and a lithium salt dissolved in an organic solvent...

The entire solar material for the sample with less than or equal to 30 percent selenium is photoactive (top) while the bottom of the solar material for the image below contains greater than 35 percent selenium and has reduced photoactivity. Credit: ORNL

Solar cells based on cadmium and tellurium could move closer to theoretical levels of efficiency because of some sleuthing by researchers at the Dept of Energy’s Oak Ridge National Lab. A team used advanced microscopy to discover efficiency differences of crystalline structures of various mixtures of cadmium, tellurium and selenium. In fact, selenium is an integral part of the formulation that resulted in a world record for solar cell efficiency.

While some of today’s solar cells use a blend of cadmium and tellurium to convert light into el...

Scientists inserted helium ions into a thin crystalline film (gold) to controllably increase the out-of-plane crystal dimension, while the underlying substrate (black) fixed the in-plane directions. The red balloon represents one helium atom in the crystalline lattice. Credit: Oak Ridge National Laboratory

With just a bit of helium, the lighter-than-air element that makes balloons float, scientists have done what was once thought impossible – they stretched a crystal lattice in just one dimension, allowing them to tune the structure’s electronic and magnetic properties. To achieve this elongation, scientists devised a new method called “strain doping.” Scientists implant helium ions into a crystal. The helium gently pushes up against the structure, like a balloon under a sheet...

Researchers have found a way to make the valuable chemical ethyl acetate while generating H2 gas to power fuel cells.
CREDIT
Nanfeng Zheng

Hydrogen is widely regarded as a promising and clean alternative energy source. The traditional source of hydrogen (H2) for fuel cell use is water, which is split into H2 and oxygen (O2). But O2 is a low-value product. So, this week in ACS Central Science, researchers report a new approach and a new catalyst that can produce not just hydrogen but also valuable chemicals, including the most common ingredient in nail polish.

Nanfeng Zheng and colleagues recognized that to produce H2, it is necessary to have a source that contains both hydrogen and oxygen. Although water is the typical source, other substances could also fit the bill...