Researchers have found an efficient, less energy-intensive, and environment-friendly way of synthesising hydrogen peroxide, a chemical that finds a range of industrial uses. Hydrogen peroxide is a versatile oxidising agent, widely used in environmental disinfection, chemical synthesis, paper bleaching, and fuel cells.
In addition, the growth of this market is driven by the rising awareness of disinfection, a rise in the number of surgeries, prevalence of hospital-acquired infections, and so on.
Currently, over 95 per cent of hydrogen peroxide is produced industrially using the anthraquinone oxidation process, which is energy-intensive, expensive and produces many hazardous chemicals as by-products.
Scientists are looking for an environment-friendly and economical means to produce hydrogen peroxide from renewable resources. In this context, a new class of porous and ordered polymers with modifiable catalytic sites and light-harvesting properties in visible range, called covalent organic frameworks (COFs), have emerged as promising photocatalysts.
Water affinity
Researchers at SN Bose National Centre for Basic Sciences, Kolkata, an autonomous institute under the Department of Science and Technology, have designed and prepared a series of COFs that have good water affinity, through careful control of the hydrazone linkage density, and studied their effect on the photocatalytic performance for hydrogen peroxide generation.
It was observed that the hydrazone-linked COFs provide abundant docking sites for water and oxygen, thereby promoting water oxidation reaction (WOR) and oxygen reduction reaction (ORR) — two main pathways for photocatalytic generation of hydrogen peroxide.
Clean pathway
“A significant amount of hydrogen peroxide (550 micromoles per gram per hour) was also produced under sunlight irradiation, which outperforms most organic photocatalysts under similar conditions, thus demonstrating a clean and sustainable pathway,” says a press release from DST.