Photocatalytic production of hydrogen peroxide using polymer bound anthraquinone. I. Photoproducts in 2‐hydroxyethyl methacrylate hydrogels swollen with water and 2‐propanol

Abstract Photoreductions of polymer‐bound anthraquinone in degassed water‐ and 2‐propanolswollen 2‐hydroxyethyl methacrylate hydrogel films were performed at 313 and 334 nm, and in sunlight for the water‐swollen system. The quantum yield at 334 nm for production of anthrahydroquinone was 0.31 in water and 0.94 in 2‐propanol. Results at 313 nm were very similar. A reversible oxygen insensitive side product, indentified as 10‐hydroxyanthrone, was produced simultaneously to the anthrahydroquinone in water‐swollen films, but not for 2‐propanol. A small amount of irreversible side product, believed to be hydroxylated anthraquinone, was also formed in the water system. A photochemical reaction scheme is suggested to account for these observations. Hydrogen peroxide production from photoreduction‐reoxidation cycling of the hydrogels is reported.