Tellurium-induced defect engineering for boosting the oxygen evolution reaction of spinel oxide

Abstract

Metalloid atom Te was adopted into oxide NiCo2O4 to optimize the electronic structure and alter the energy level of the d band center as a highly efficient OER catalyst.

Bird Nest-Like Fe3O4/CoOx Nanosphere Heterojunctions with Amorphous/Crystalline Structure for Enhanced Electrochemical Oxygen Evolution

“…On the contrary, the fitting peak of Co 0 disappeared, possibly because Co 0 in BN-Fe 3 O 4 /CoO x was oxidized to Co 2+ during the OER process, resulting in a decrease in the ratio of Co 3+ /Co 2+ (Figure S14c). 32,63 As shown in Figure S14d, the proportions of the lattice oxygen (O latt ), oxygen vacancy (O v ), and adsorbed oxygen (O ads ) are 30.72, 50.92, and 18.36%, respectively, illustrating that the content of oxygen vacancy does not change considerably, proving that the charge transfer rate is still fast. So far, it could come to a conclusion that the crystalline structure often has higher catalytic performance due to more exposure to crystal faces, while the amorphous structure has a greater advantage in maintaining the overall stability of the material structure.…”

“…In addition, as shown in Figure S12, after 1000 CV cycles at a scan rate of 100 mV s −1 , the overpotential increased by only 10 mV, that is, the increment is 3.5%, which is almost negligible, both revealing the outstanding durability of BN-Fe 3 O 4 /CoO x toward OER. 14,63 Meanwhile, to further verify the stability of the morphology and chemical composition of the catalyst, SEM, TEM, XRD, and XPS of the BN-Fe 3 O 4 /CoO x nanosphere after 1000 CV cycles were evaluated as well. As shown in Figure S13a,b, the morphology of the material has not changed significantly, proving that the BN-Fe 3 O 4 /CoO x catalyst has excellent structural stability.…”