Gadolinium‐Induced Valence Structure Engineering for Enhanced Oxygen Electrocatalysis
Meng Li, Yu Wang, Yang Zheng, Gengtao Fu, Dongmei Sun, Yafei Li, Yawen Tang, Tianyi Ma
Abstract
Abstract Rare earth doped materials with unique electronic ground state configurations are considered emerging alternatives to conventional Pt/C for the oxygen reduction reaction (ORR). Herein, gadolinium (Gd)‐induced valence structure engineering is, for the first, time investigated for enhanced oxygen electrocatalysis. The Gd 2 O 3 –Co heterostructure loaded on N‐doped graphene (Gd 2 O 3 –Co/NG) is constructed as the target catalyst via a facile sol–gel assisted strategy. This synthetic strategy allows Gd 2 O 3 –Co nanoparticles to distribute uniformly on an N‐graphene surface and form intimate Gd 2 O 3 /Co interface sites. Upon the introduction of Gd 2 O 3 , the ORR activity of Gd 2 O 3 –Co/NG is significantly increased compared with Co/NG, where the half‐wave potential (E 1/2 ) of Gd 2 O 3 –Co/NG is 100 mV more positive than that of Co/NG and even close to commercial Pt/C. The density functional theory calculation and spectroscopic analysis demonstrate that, owing to intrinsic charge redistribution at the engineered interface of Gd 2 O 3 /Co, the coupled Gd 2 O 3 –Co can break the OOH*–OH* scaling relation and result in a good balance of OOH* and OH* binding on Gd 2 O 3 –Co surface. For practical application, a rechargeable Zn–air battery employing Gd 2 O 3 –Co/NG as an air–cathode achieves a large power density and excellent charge–discharge cycle stability.