| Autor: |
Neaţu Ş; National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania., Neaţu F; National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania., Diculescu VC; National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania., Trandafir MM; National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania., Petrea N; Scientific Research Centre for CBRN Defence and Ecology, 225 Oltenitei Road, 041309 Bucharest, Romania., Somacescu S; 'Ilie Murgulescu' Institute of Physical Chemistry, Romanian Academy, Spl. Independentei 202, 060021 Bucharest, Romania., Krumeich F; ETH Zurich, Institute for Chemical and Bioengineering, 8093 Zurich, Switzerland., Wennmacher JTC; ETH Zurich, Institute for Chemical and Bioengineering, 8093 Zurich, Switzerland.; Paul Scherrer Institute, 5232 Viligen, Switzerland., Knorpp AJ; ETH Zurich, Institute for Chemical and Bioengineering, 8093 Zurich, Switzerland., van Bokhoven JA; ETH Zurich, Institute for Chemical and Bioengineering, 8093 Zurich, Switzerland.; Paul Scherrer Institute, 5232 Viligen, Switzerland., Florea M; National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania. |
| Abstrakt: |
In this study, the synergistic behavior of Ni species and bimodal mesoporous undoped SnO 2 is investigated in oxygen evolution reactions (OERs) under alkaline conditions without any other modification of the compositional phases or using noble metals. An efficient and environmentally friendly hydrothermal method to prepare bimodal mesoporous undoped SnO 2 with a very high surface area (>130 m 2 g -1 ) and a general deposition-precipitation method for the synthesis of well-dispersed Ni species on undoped SnO 2 are reported. The powders were characterized by adsorption-desorption isotherms, TG-DTA, XRD, SEM, TEM, Raman, TPR-H 2 , and XPS. The best NiSn composite generates, under certain experimental conditions, a very high TOF value of 1.14 s -1 and a mass activity higher than 370 A g -1 , which are remarkable results considering the low amount of Ni deposited on the electrode (3.78 ng). Moreover, in 1 M NaOH electrolyte, this material produces more than 24 mA cm -2 at an overpotential value of approximately +0.33 V, with only 5 wt % Ni species. This performance stems from the dual role of undoped SnO 2 , on the one hand, as a support for active and well-dispersed Ni species and on the other hand as an active player through the oxygen vacancies generated upon Ni deposition. |
