Vacunacionadultos

Researchers make theoretical prediction of 2-D semiconductor tin dioxide

Researchers make theoretical prediction of 2-D semiconductor tin dioxide
Fig. 1. (a) The atomic structure of a 2D δ-SnO2 monolayer. (b) The strain in the x direction resulting from an applied tensile strain in the y direction. Credit: JIANG Peng

Recently, Prof. Zheng Xiaohong’s research group from the Institute of Solid State Physics (ISSP) of the Hefei Institute of Physical Science (HFIPS) predicted a new two-dimensional (2-D) tin dioxide (SnO2) monolayer phase (P-4 m2) via first-principles calculations.

Bulk SnO2 is an important n-type wide-bandgap (~3.6 eV) semiconductor and is widely used as electrode materials, chemical sensor components, etc. but systematic study of possible tin oxide phases in 2-D is still missing. In particular, given the claims of magnetism in SnO2 thin films, it is worth investigating whether a stable SnO2 2-D phase can be synthesized or magnetism can be induced.

In this research, the researchers provided direct evidence of a stable and

Read More

Sun-Powered Chemistry Can Turn Carbon Dioxide into Common Materials

The manufacture of many chemicals important to human health and comfort consumes fossil fuels, thereby contributing to extractive processes, carbon dioxide emissions and climate change. A new approach employs sunlight to convert waste carbon dioxide into these needed chemicals, potentially reducing emissions in two ways: by using the unwanted gas as a raw material and sunlight, not fossil fuels, as the source of energy needed for production.

This process is becoming increasingly feasible thanks to advances in sunlight-activated catalysts, or photocatalysts. In recent years investigators have developed photocatalysts that break the resistant double bond between carbon and oxygen in carbon dioxide. This is a critical first step in creating “solar” refineries that produce useful compounds from the waste gas—including “platform” molecules that can serve as raw materials for the synthesis of such varied products as medicines, detergents, fertilizers and textiles.

Photocatalysts are typically semiconductors, which require high-energy ultraviolet light to

Read More

New sulfur dioxide conversion method may transform current industrial techniques

New sulfur dioxide conversion method may transform current industrial techniques
Schematic illustration of the plasma catalytic sulfur dioxide reduction with hydrogen or methane to sulfur at low temperature. Credit: Penn State

A single-step, plasma-enhanced catalytic process to convert sulfur dioxide to pure sulfur from tail gas streams may provide a promising, more environmentally-friendly alternative to current multistage thermal, catalytic and absorptive processes, according to scientists at Penn State.


“Sulfur dioxides can cause significant environmental problems like acid rain, and it can cause sea acidification,” said Xiaoxing Wang, associate research professor at the Penn State EMS Energy Institute. “Sulfur can also contribute to fine particulate matter in the air we breathe, which can be more severe than the sulfur dioxide itself.”

Exposure to particulate matter was estimated to cause 4.2 million premature deaths and more than 100 million disability-adjusted life years—which measures years lost due to illness, disability or death—according to the Lancet Global Burden of Diseases Study, published in 2015.

Read More

Chemists develop new material for the separation of carbon dioxide from industrial waste gases

Chemists develop new material for the separation of CO₂ from industrial waste gases
Electron microscopic cross-sectional image of the new hybrid material. It was possible to produce the glass platelets very precisely and, interrupted by spacers, to layer them on top of each other. Credit: Martin Rieß

Chemists at the University of Bayreuth have developed a material that could well make an important contribution to climate protection and sustainable industrial production. With this material, the greenhouse gas carbon dioxide (CO₂) can be specifically separated from industrial waste gases, natural gas, or biogas, and thereby made available for recycling. The separation process is both energy efficient and cost-effective. In the journal Cell Reports Physical Science the researchers present the structure and function of the material.


The Green Deal presented by the European Commission in 2019 calls for the net emissions of greenhouse gases within the EU to be reduced to zero by 2050. This requires innovative processes that can separate and retain CO2

Read More

Deep-sea corals reveal secrets of rapid carbon dioxide increase as the last ice age ended

Deep-sea corals reveal secrets of rapid carbon dioxide increase as the last ice age ended
Researchers examined deep-sea coral fossils – species Desmophyllum dianthus – to study carbon sequestration in the Southern Ocean 20,000 to 10,000 years ago. The chemical signatures of nitrogen and carbon in the coral fossils revealed that ocean carbon sequestration decreased as phytoplankton failed to devour macronutrients supplied by upwelling currents in the Southern Ocean and trap carbon dioxide in the deep ocean. Credit: Tony Wang, Boston College

The Southern Ocean played a critical role in the rapid atmospheric carbon dioxide increase during the last deglaciation that took place 20,000 to 10,000 years ago, according to a new report by Boston College geochemist Xingchen (Tony) Wang and an international team in the online edition of Science Advances.


In this new study, Wang and his coauthors analyzed deep-sea coral fossils from 20,000 to 10,000 years ago, when atmospheric carbon dioxide was on the rise.

By examining the chemical signatures of nitrogen

Read More

Membranes for capturing carbon dioxide from the air

Membranes for capturing carbon dioxide from the air
Technological solutions for the CO2 emission into the atmosphere should include variety of approaches as there is no one “silver bullet” solution. In this work researchers from I2CNER, Kyushu University and NanoMebrane Technologies Inc. Japan suggest using the gas separation membranes as a tool for direct air capture. When combined with advanced technologies for CO2 conversion the envisaged systems can be widely employed in carbon-recycling sustainable society. Credit: Kyushu University

Climate change caused by emissions of greenhouse gases into the atmosphere is a pressing issue for our society. Acceleration of global warming results in catastrophic heatwaves, wildfires, storms and flooding. The anthropogenic nature of climate change necessitates development of novel technological solutions in order to reverse the current CO2 trajectory.


Direct capture of the carbon dioxide (CO2) from the air (direct air capture, DAC) is one among a variety of negative emission technologies that are expected to

Read More