International Journal of Hydrogen Energy, Vol.40, No.15, 5081-5091, 2015
Introducing polyethyleneimine (PEI) into the electrospun fibrous membranes containing diiron mimics of [FeFe]-hydrogenase: Membrane electrodes and their electrocatalysis on proton reduction in aqueous media
A number of fibrous membranes with cellulose acetate as a matrix and functionalised with diiron mimics of the diiron subunit of [FeFe]-hydrogenase were prepared by electrospinning technique. Four mimics, [Fe-2(mu-edt) (CO)(6)] (1), [Fe-2{mu-SCH2CH(CH2OH)S}(CO)(6)] (2), [Fe-2{(mu-S)(2)(C6O2H4)(CO)(6)] (3) and [Fe-2{mu-SCH2CH(OH)CH2(OH))(2)(CO)(6)] (4), bearing 0, 1,2 and 4 hydroxyl group(s) were incorporated into the electrospun fibrous membranes (EFMs). To improve the conductivity of the EFMs, graphene oxide was chemically gratified onto cellulose acetate. The resultant EFMs membranes were characterized using infrared spectroscopic, thermogravimetric and scanning electron microscopic techniques. The electrochemical behaviours and electrocatalytic performance on proton reduction of the membrane electrodes assembled from the EFMs showed in aqueous media that the membrane (M2) containing complex 2 is most durable and exhibited the best catalytic performance. To the electrospinning system containing complex 2 was further doped with basic polymer PEI to enhance tentatively proton transfer during the electrocatalysis of proton reduction. Our results showed that the presence of PEI in the EFMs did improve the electrocatalytic performance of proton reduction, presumably due to the enhancement in proton transfer in the catalysis. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Electrospun fibre;Membrane electrode;[Fe-Fe]-hydrogenase;Hydrogen evolution;Electrocatalysis