Visible light can catalyze the chemical reactions involved in industrial processes.
The manufacture of many chemicals, essential for human health and comfort, depend on fossil fuels, which contributes to the expansion of fuel extraction processes, and thus the increase in carbon dioxide emissions, and the exacerbation of the problem of climate change.
A new approach has emerged, which relies on sunlight to convert carbon dioxide resulting from combustion processes into useful chemicals.
This will lead to reducing emissions in two ways:
The use of unwanted gas as a raw material, on the one hand, and dependence on sunlight, And not fossil fuels, to be the source of energy needed for production on the other hand.
It is noted that this process has become more feasible, thanks to the progress made in the production of catalysts that are activated when exposed to sunlight or light. Over recent years, researchers have succeeded in developing catalysts capable of breaking the double-resistance bond between carbon and oxygen in carbon dioxide. This is considered as a very important first step towards establishing "solar" refineries, which produce useful compounds from exhaust gas, including so-called "basic" particles, which can play the role of raw materials used in the composition of various products, including medicines, detergents, and fertilizers, And textiles.
It is known that the photocatalysts that are activated upon exposure to light are usually semiconductors, requiring high-energy ultraviolet rays to generate the electrons responsible for converting carbon dioxide.
However, UV rays are scarce in nature (representing only 5% of the sun's rays), and they are harmful. Hence, the development of new catalysts activated by visible light, the most available, and the least harmful, was a major goal of researchers, who are working to achieve this goal by making precise adjustments to the composition of the already existing catalysts, as well as to their structure and external form, and from these Compounds, for example, titanium dioxide.
Although this compound efficiently converts carbon dioxide into other molecules when exposed to UV rays alone, activating it with nitrogen greatly reduces the energy needed to do so.
Thus, the modified catalyst no longer requires only visible light to produce widely used chemicals, such as methanol, formaldehyde and formic acid, which are important in the manufacture of adhesives, foams, plywood, woodwork, floors and disinfectants.
It should be noted that currently, solar chemical research is mainly conducted in academic laboratories, including the Joint Center for Artificial Photosynthesis, run by the California Institute of Technology, in partnership with the Lawrence Berkeley National Laboratory. And also includes the "Sunrise Consortium", a coalition based in the Netherlands, which includes a number of universities, industrial, research and technological institutions, in addition to the heterogeneous interactions section of the Max Planck Institute for Chemical Energy Conversion, which is located in the city of Mulheim, Germany.
In addition, some emerging companies are developing a new approach to converting carbon dioxide into useful materials, based on the use of electricity to stimulate chemical reactions.
It goes without saying that using electricity to power reactions would be a less environmentally conscious approach than relying on sunlight, in the event that electrical energy is the result of fossil fuel combustion, but relying on photovoltaics can overcome this obstacle.
There is no doubt that the progress in converting carbon dioxide into chemicals based on sunlight will be invested commercially, and will find further development by start-ups or other companies in the coming years.
By converting carbon dioxide - which today is no more than exhaust from combustion processes - into valuable products, the chemical industry will take a new step on the road to becoming a true circular economy, free of waste, and will help make the desired goal of Generating emissions that reduce rather than increase CO2 concentrations is a tangible reality.