Gadolinium‐Induced Valence Structure Engineering for Enhanced Oxygen Electrocatalysis

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 Gd2O3–Co heterostructure loaded on N‐doped graphene (Gd2O3–Co/NG) is constructed as the target catalyst via a facile sol–gel assisted strategy. This synthetic strategy allows Gd2O3–Co nanoparticles to distribute uniformly on an N‐graphene surface and form intimate Gd2O3/Co interface sites. Upon the introduction of Gd2O3, the ORR activity of Gd2O3–Co/NG is significantly increased compared with Co/NG, where the half‐wave potential (E1/2) of Gd2O3–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 Gd2O3/Co, the coupled Gd2O3–Co can break the OOH*–OH* scaling relation and result in a good balance of OOH* and OH* binding on Gd2O3–Co surface. For practical application, a rechargeable Zn–air battery employing Gd2O3–Co/NG as an air–cathode achieves a large power density and excellent charge–discharge cycle stability.

Valence Engineering via In Situ Carbon Reduction on Octahedron Sites Mn3O4 for Ultra‐Long Cycle Life Aqueous Zn‐Ion Battery

“…In addition, the electronic structure affects the Gibbs free energy of metal ion adsorption on the surface of the material. [ 13 ] Zhou et al. treated β‐MnO 2 with 0.25 m NaBH 4 to produce surface oxygen defects, which has a high specific capacity of 302 mAh g −1 .…”

Graphitic‐shell encapsulated FeNi alloy/nitride nanocrystals on biomass‐derived N‐doped carbon as an efficient electrocatalyst for rechargeable Zn‐air battery

“…The discharge‐charge voltage gap at 60 mA/cm 2 is only 0.93 V, contributing to an energy efficiency of 54.0% (Figure S12). In addition, the peak power density could be as high as approximately 350 mW/cm 2 , which is much higher than that of Pt/C (250 mW/cm 2 ), 31 and also much superior to those reported for Zn‐air primary batteries 40‐43 . Moreover, the excellent rechargeability of the Fe x Ni y N@C/NC was demonstrated by more than 400 discharge/charge cycles over 400 hours (Figure 6C).…”

“…In addition, the peak power density could be as high as approximately 350 mW/cm 2 , which is much higher than that of Pt/C (250 mW/cm 2 ), 31 and also much superior to those reported for Zn-air primary batteries. [40][41][42][43] Moreover, the excellent rechargeability of the Fe demonstrated by more than 400 discharge/charge cycles over 400 hours (Figure 6C). After more than 400 cycles, the final discharge-charge voltage gap is only 0.80 V, which remains nearly unchanged.…”

Facile Synthesis of Carbon Cloth Supported Cobalt Carbonate Hydroxide Hydrate Nanoarrays for Highly Efficient Oxygen Evolution Reaction

“…Figure 2C shows the high-resolution Co 2p XPS spectrum, which can be best fitted with two spin-orbit doublets and two shakeup satellites. The fitting peaks at 782.40 and 798.10 eV are assigned to Co 2+ species, whereas the fitting peaks at 780.46 and 796.40 eV are attributed to Co 3+ species (Li et al, 2020a;Li et al, 2020b). For O 1s XPS spectrum, the peaks located at 530.3, 530.95 and 532.40 eV are associated with metal-oxygen bond, hydroxyl group (OH − ) and oxygen vacancies (Tang et al, 2020;Li M. et al, 2021).…”