Release time:2021-03-15  Hits:

• Key Words:Oxygen;Catalysts - Doping (additives) - Electrocatalysts - Electrolytic reduction - Lanthanum alloys - Nitrogen - Perovskite - Secondary batteries - Urea - Yarn;Bi-functional catalysts - Bifunctional activity - Bifunctional electrocatalysts - Calcination treatment - N-doped - Nitrogen-doped carbons - Oxygen evolution reaction - Oxygen reduction reaction
• Abstract:A robust bifunctional electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly desired for the application in rechargeable metal air batteries. Here, we report a new strategy to in-situ prepare La<inf>2</inf>O<inf>3</inf>-nitrogen doped carbon tubes (NCNTs) hybrids by one step calcination treatment with LaNi<inf>0.9</inf>Fe<inf>0.1</inf>O<inf>3</inf>perovskite oxides as precursors, sugar as carbon sources and urea as nitrogen sources. The contents of applied LaNi<inf>0.9</inf>Fe<inf>0.1</inf>O<inf>3</inf>oxides affect the formation of NCNTs, and the obtained NCNTs have abundant wrinkles on the surface. In alkaline solution, the LO-NF-NCNTs-1.0 sample catalyzes the ORR with an onset potential of 0.896&nbsp;V (vs. RHE) and a half-wave potential (E<inf>1/2</inf>) of 0.772&nbsp;V (vs. RHE), which is only an E<inf>1/2</inf>gap of 65&nbsp;mV compared with commercial Pt/C catalyst. Meanwhile, the LO-NF-NCNTs-1.0 sample exhibits better OER activities than the commercial RuO<inf>2</inf>catalyst. Significantly, we demonstrate that the LO-NF-NCNTs-1.0 sample possesses surprisingly catalytic stabilities, and an outstanding tolerance towards methanol crossover. The excellent bifunctional activities may be attributed to the typical morphology of NCNTs, coupling effect between NCNTs and La<inf>2</inf>O<inf>3</inf>because of the formation of active La[sbnd]O and C[sbnd]O bonds. &copy; 2017 Elsevier Ltd
• Volume:115
• Translation or Not:no