• Researchers have developed an innovative, energy-efficient, and environmentally friendly method for synthesizing hydrogen peroxide (H₂O₂), a chemical widely used in industries for disinfection, paper bleaching, and other applications. 

• This breakthrough could significantly reduce the environmental impact and energy consumption associated with traditional production methods.

• Hydrogen peroxide is a versatile oxidising agent essential for various applications, including environmental disinfection, chemical synthesis, paper bleaching, and fuel cells. 

• The growing demand for H₂O₂ is driven by increased awareness of disinfection, rising surgical procedures, and the prevalence of hospital-acquired infections. 

• Currently, over 95 per cent of industrial H₂O₂ is produced through the anthraquinone oxidation process, which is energy-intensive, costly, and generates hazardous by-products.

• To address these challenges, scientists are exploring sustainable and economical strategies for producing H₂O₂ from renewable resources with minimal environmental impact. 

• A promising approach involves the use of covalent organic frameworks (COFs), a class of porous, ordered polymers with modifiable catalytic sites and light-harvesting properties in the visible range.

Key Findings:

• Researchers at the S. N. Bose National Centre for Basic Sciences, Kolkata, an autonomous institute under the Department of Science and Technology (DST), designed a series of hydrazone-linked COFs with excellent water affinity. 

These COFs were engineered to optimise photocatalytic performance for H₂O₂ generation by promoting two key reactions:

i) Water Oxidation Reaction (WOR)

ii) Oxygen Reduction Reaction (ORR).

• The hydrazone-linked COFs demonstrated exceptional photocatalytic H₂O₂ production under irradiation with a 40 W blue LED (λ = 467 nm) without requiring external sacrificial electron donors. 

• Notably, the COFs also achieved significant H₂O₂ production (550 μmol g⁻¹ h⁻¹) under sunlight, outperforming most organic photocatalysts under similar conditions.

• The researchers further enhanced H₂O₂ production by using an aqueous benzyl alcohol solution (water: benzyl alcohol = 90:10), which prevented H₂O₂ degradation and achieved a remarkable production rate of 21,641 μmol g⁻¹ h⁻¹. 

• This approach paves the way for developing continuous flow reactors for sustainable H₂O₂ production, enabling a seamless transition from laboratory research to industrial-scale applications.

(The author is a trainer for Civil Services aspirants.)