HYBRID PHOTOELECTROCATALYST FOR MOLECULAR OXYGEN REDUCTION BASED ON REDUCED GRAPHENE OXIDE AND P3HT:C60(CF3)H

Metal-free photoelectrocatalysts of the oxygen reduction reaction (ORR) composed of electroreduced graphene oxide (ERGO), donor polymer P3HT and fullerene acceptor C60(CF3)H are described. We have shown that the utilization an ERGO interface layer is beneficial for the design of the efficient and stable ORR photoelectrodes. FTO-coated glass substrates (fluorine-doped tin oxide) were used for the photoelectrodes fabrication. A thin layer of graphene oxide was deposited by spin-coating at the FTO surface following by its electrochemical reduction to form ERGO layer. Then, a bulk heterojunction (BHJ) layer of P3HT and C60(CF3)H was deposited at FTO/ERGO surface via spin-coating following by its annealing to form the photoelectrode FTO/ERGO/BHJ. ORR catalytic activity of the fabricated FTO, FTO/ERGO, FTO/BHJ, and FTO/ERGO/BHJ photoelectrodes was compared using cyclic voltammetry (PBS, pH=7.4; white light irradiation, 100 mW cm–2). The FTO/ERGO photoelectrode demonstrates the ORR electrocatalytic behavior. For the FTO/ERGO photoelectrode, the ORR current density increases by 27 times, and the overpotential decreases by 0.1 V compared to the values for the FTO photoelectrode. The FTO/BHJ and FTO/ERGO/BHJ photoelectrodes have a pronounced photocatalytic effect. The irradiation of the FTO/BHJ and FTO/ERGO/BHJ photoelectrodes with white light increases the ORR current density more than 2 and 3 times, respectively, compared with the values for the FTO/ERGO photoelectrode. The overpotential is reduced by 0.3 V. Chronoamperometric studies have shown that the FTO/ERGO/BHJ photoelectrode works stably for more than 20 h, while the FTO/BHJ photoelectrode undergoes peeling of the BHJ photoactive film. The hybrid FTO/ERGO/BHJ photoelectrodes are high-efficient ORR photoelectrocatalysts with decreased overpotential (similar with that for the efficient metal-containing electrocatalysts of the non-platinum group), and operating lifetime of more than 20 h. Deposition of ERGO layer at the FTO surface improves the adhesion of the photoactive layer while maintaining high charge-transport characteristics. Thus, the engineering of the long-lifetime polymer-based ORR photoelectrodes is possible via introduction of the ERGO interface layer between photoactive BHJ and FTO layers. For citation: Malkin N.A., Brotsman V.A., Lukonina N.S., Goryunkov A.A. Hybrid photoelectrocatalyst for molecular oxygen reduction based on reduced graphene oxide and P3HT:C60(CF3)H. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 9. P. 90-98. DOI: 10.6060/ivkkt.20256809.1y.