Cobalt-based nanomaterials have been intensively explored as one of the most promising noble-metal-free oxygen evolution reaction (OER) electrocatalysts. However, most of their performances are still inferior to state...Cobalt-based nanomaterials have been intensively explored as one of the most promising noble-metal-free oxygen evolution reaction (OER) electrocatalysts. However, most of their performances are still inferior to state-of-the-art precious metals especially for Ru and Ir.Herein, we apply a continuous ion exchange method and further hydrothermal treatment to synthesize the flake-like Ag-CoSO4 nanohybrids beginning from Co-BTC (BTC:benzene-1,3,5-tricarboxylic acid) metal-organic frameworks precursor. The catalyst exhibits superior OER performance under the alkaline electrolyte solution (a low overpotential of 282 mV at 10 mA/cm2 in 1 mol/L KOH), which is even better than RuO2 due to the improved conductivity and rapid electrons transfer process via introducing small amount of Ag. The existence of Ag in the hybrids is beneficial for increasing the Co(IV) concentration, thus promoting the *OOH intermediate formation process. Besides, due to the very low requirement of Ag content (lower than 1 atom%), the cost of the catalyst is also limited. This work provides a new insight for designing of inexpensive OER catalysts with high performance and low cost.展开更多
Electrolyte-diffusion of CoSO4 in pure aqueous solution is studied at 25 ℃ over a concentration range of 10-5-0.25 mol/l. The measurement of diffusion coefficients are done by improved capillary technique without sti...Electrolyte-diffusion of CoSO4 in pure aqueous solution is studied at 25 ℃ over a concentration range of 10-5-0.25 mol/l. The measurement of diffusion coefficients are done by improved capillary technique without stirring. These values are compared with the theoretical values computed on the basis of Onsager-Fuoss theory.展开更多
基金supported by the National Natural Science Foundation(No.21271163,No.1232211,No.21571168)the Fundamental Research Funds for the Central Universities(WK2060140021)the CAS/SAFEA International Partnership Program for Creative Research Teams and the Hefei Science Center CAS(2016HSC-IU011)
文摘Cobalt-based nanomaterials have been intensively explored as one of the most promising noble-metal-free oxygen evolution reaction (OER) electrocatalysts. However, most of their performances are still inferior to state-of-the-art precious metals especially for Ru and Ir.Herein, we apply a continuous ion exchange method and further hydrothermal treatment to synthesize the flake-like Ag-CoSO4 nanohybrids beginning from Co-BTC (BTC:benzene-1,3,5-tricarboxylic acid) metal-organic frameworks precursor. The catalyst exhibits superior OER performance under the alkaline electrolyte solution (a low overpotential of 282 mV at 10 mA/cm2 in 1 mol/L KOH), which is even better than RuO2 due to the improved conductivity and rapid electrons transfer process via introducing small amount of Ag. The existence of Ag in the hybrids is beneficial for increasing the Co(IV) concentration, thus promoting the *OOH intermediate formation process. Besides, due to the very low requirement of Ag content (lower than 1 atom%), the cost of the catalyst is also limited. This work provides a new insight for designing of inexpensive OER catalysts with high performance and low cost.
文摘Electrolyte-diffusion of CoSO4 in pure aqueous solution is studied at 25 ℃ over a concentration range of 10-5-0.25 mol/l. The measurement of diffusion coefficients are done by improved capillary technique without stirring. These values are compared with the theoretical values computed on the basis of Onsager-Fuoss theory.
