‘Greening’ silicon production for a future with net zero emissions

What is it about?

From adhesives, biological implants, to electronics, silicon-based materials are ubiquitous in modern society and integral to any development based on modern technology. But at present, their production leaves large carbon footprints: methods are highly energy intensive, polluting, and unsustainable. Over the past few decades, research on silicon-based materials have focused on ‘green’ production methods, such as production from rice hull ash (RHA), the burned by-product of rice grain production, approximately 134 million tonnes of which is available each year. This review explores the various advantages of using RHA as a raw material over mined silica: it has about 85% silica content, high surface area, and high reactivity, meaning that its use would require lower energy; using it prevents its open burning, not only reducing carbon emissions but also allowing for processes of producing silicon-based materials that result in near net zero emissions. The review also looks at the various RHA processing methods to yield silicon-based materials and their potential applications. Further, it explores other biogenic silica sources.

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Photo by Anne Nygård on Unsplash

Photo by Anne Nygård on Unsplash

Why is it important?

Silicon-based materials are not only at the core of many modern technologies, but they are versatile and can be have even broader applications than are currently known. Moreover, they degrade with minimal negative environmental impact. So, it is without doubt that they should be an integral part of a greener future. The greening of silicon chemistry is still slow and difficult. But it could rapidly make a silicon-based society with net-zero emissions possible. KEY TAKEAWAY: Silicon chemists should be cognizant of the environmental impacts of producing silicon-based materials and further the research on green methods of production.