Efficient Generation of Hydrogen Peroxide and Formate by an Organic Polymer Dots Photocatalyst in Alkaline Conditions

A photocatalyst comprising binary organic polymer dots (Pdots) was prepared. The Pdots were constructed from poly(9,9-dioctylfluorene-alt-benzothiadiazole), as an electron donor, and 1-[3-(methoxycarbonyl)propyl]-1-phenyl-[6.6]C₆₁ , as an electron acceptor. The photocatalyst produces H₂ O₂ in alkaline conditions (1 M KOH) with a production rate of up to 188 mmol h^-1  g^-1 . The external quantum efficiencies were 30 % (5 min) and 14 % (75 min) at 450 nm. Furthermore, photo-oxidation of methanol by Pdots, followed by a disproportionation reaction and an oxidation reaction, produced the high-value chemical formate. On the basis of various spectroscopic and electrochemical measurements, the photophysical processes of the system were studied in detail and a reaction mechanism was proposed.