Piezocatalytic H2O2 Production

Hydrogen peroxide is a widely used environmentally friendly oxidant. The traditional anthraquinone process for producing H₂O₂ has drawbacks such as high energy consumption and safety risks. The development of alternative efficient, green, and economical methods for H₂O₂ production is, thus, an interesting research target. Piezocatalysis could be a useful approach for this. In piezocatalysis, the piezoelectric effect is used to convert mechanical energy, such as vibrations from the environment, into electric energy and trigger reactions.

Shuchen Tu, South China Normal University, Guangzhou, China, Changlin Yu, Xiangming Li, Guangdong University of Petrochemical Technology, Maoming, China, and colleagues have developed a piezocatalyst for H₂O₂ production. The team prepared metal-organic cage (MOC)-coated gold nanoparticles that are anchored on graphitic carbon nitride (MOC-AuNP/g-C₃N₄). The metal-organic cages (MOC-OH) were synthesized from zirconocene dichloride and 2-hydroxyterephthalic acid, and the coated gold nanoparticles were then obtained by an in-situ reduction of Au³⁺ using the metal-organic cages. The team prepared ultrathin graphitic carbon nitride using a hydrothermal reaction and thermal polymerization. The MOC-coated gold nanoparticles and the graphitic carbon nitride were then assembled to obtain the desired MOC-AuNP/g-C₃N₄ nanohybrid.

The synthesized MOC-AuNP/g-C₃N₄ can be used as an efficient piezocatalyst to generate H₂O₂ at rates up to 120.21 μmol g^–1 h^–1 in air and water. According to the researchers, the MOC component enhances substrate (O₂) and product (H₂O₂) adsorption via host-guest interactions and hinders rapid H₂O₂ decomposition, while the gold nanoparticle component affords a strong interfacial electric field that promotes the migration of electrons from the graphitic carbon nitride for the O₂ reduction reaction. Overall, the work shows the potential of multi-site engineered materials as piezoelectric catalysts for H₂O₂ synthesis.