Converting water impurity in organic solvent into hydrogen and hydrogen peroxide by organic semiconductor photocatalyst

Abstract

Photocatalytic water-splitting to generate hydrogen (H2) and hydrogen peroxide (H2O2) is a green and renewable method to convert solar energy into chemical energy. The water impurity in organic solvents is usually hard to be removed. Here, we firstly used an organic semiconductor (DAnTMS) synthesized from 9,10-dibromoanthracene and trimethylsilylacetylene to convert the water impurity in organic solvent into H2 and H2O2 by photocatalysis. Under visible light, for 300.0 μL water in 20.0 mL methyl cyanide (MeCN) system, the DAnTMS catalyst can produce H2 and H2O2 with rate of 245.9 μmol g−1 h−1 and 3923.4 μmol g−1 h−1, respectively. Furthermore, a practical photocatalytic experiment was performed in 20.0 mL commercially available MeCN (99.8%, H2O ≤ 0.01%) with 10.0 mg DAnTMS as catalyst, in which, the total 15.4 μmol H2 and 176.7 μmol H2O2 were generated after 12 h reaction, suggesting the water impurity in MeCN was completely removed. In present catalytic system, on DAnTMS, O2 and H2O are reduced into H2O2 and H2, respectively, while, H2O is oxidized into H2O2 through a 2e- pathway.