NiO and Co3O4 nanofiber catalysts for the hydrogen evolution reaction at liquid/liquid interfaces

The development of the non-precious, earth abundant and inexpensive catalysts with high catalytic efficiency for the electrocatalytic hydrogen evolution reaction acts an essential role in sustainable energy conversion and storage. Herein, we report that hydrogen evolution in two-phase systems by an organic soluble electron donor decamethylferrocene (DMFc) has been efficiently catalyzed by Co3O4 and NiO nanofiber catalysts, which are fabricated by the low-cost and simple electrospinning method. The catalytic activities of these metal oxide nanofibers have been examined by two-phase reactions and four-electrode cyclic voltammetry methods at water/1,2 dichloroethane interface. The hydrogen evolution reaction rate of nanofiber catalysts is also compared to the bulk forms of these metal oxide catalysts. The reaction rate is increased 74, 152, 284 and 384 times by using bulk and nanofiber forms of Co3O4 and NiO, respectively, when compared to an uncatalyzed reaction. The higher catalytic activity of the metal oxide nanofibers can be ascribed to the enhanced surface to volume ratio revealed from the fibrous structures.