Engineering Gd2O3-Ni heterostructure for efficient oxygen reduction electrocatalysis via the electronic reconfiguration and adsorption optimization of intermediates

Abstract

• A simple yet effective sol gel strategy to form Gd 2 O 3 -Ni/CNT hybrids. • Gd 2 O 3 -Ni/CNT endows excellent ORR performance. • Superior property is resulted from the electronic reconfiguration of Gd 2 O 3 and Ni. • The as-prepared electrode exhibits high power density and capacity in ZAB. A 3D nano-aerogel electrocatalyst is produced based on metal Ni combined with Gd 2 O 3 species through a facile hydrogel route. The synthetic method hinges on the fabrication of oxidized carbon nanotubes (OCNTs) crosslinked poly (vinyl alcohol) to form hydrogel, which permits effective catch of highly active Gd 2 O 3 /Ni particles after pyrolysis. The designed Gd 2 O 3 -Ni heterostructure on carbon nanotubes (Gd 2 O 3 -Ni/CNT) is highly efficient for oxygen reduction electrocatalysis. It is found that the half-wave potential (E 1/2 ) of Gd 2 O 3 -Ni/CNT is nearly 190 mV positive than that of Ni/CNT and even surpasses the commercial Pt/C. The superior performance is resulted from the electronic reconfiguration between Gd 2 O 3 and Ni in the heterostructure, which further optimized the adsorption of intermediates to balance the binding of OOH* and OH* on the surface of Gd 2 O 3 -Ni and break the OOH*–OH* scaling relation. Finally, the assembled zinc-air battery with Gd 2 O 3 -Ni/CNT as electrocatalyst achieves high capacity.