LAUSR

Abstract The surface property of an electrocatalyst is crucial for oxygen evolution reaction (OER). In this work, we have successfully prepared CoMoO4 nanorods (NR) with {100} facets exposed mainly and CoMoO4 nanosheets (NS) with {010} exposed mainly via a facile hydrothermal route. It is found that although the CoMoO4 NS has a 7 times higher surface area (49.3 m2 g−1) than the CoMoO4 NR (7.0 m2 g−1), the CoMoO4 NR has a 5.7 times higher OER current density (8.93 mA cmcat−2) than the CoMoO4 NS (1.56 mA cmcat−2) at 550 mV. Its higher intrinsic OER activity is mainly attributed to the exposed {100} facets of CoMoO4 NR. Compared with {010} facets (0.41 Jm-2), the {100} facets with a higher surface energy (0.54 Jm-2) are more reactive, and the more Co atoms on (100) surface can provide more OER active sites. This work demonstrates that the control of active facets exposed is a promising way for the development of efficient OER catalysts.