Abstract
Electrocatalysts play an important role in oxygen reduction reaction (ORR) in promoting the reaction process. Although commercial Pt/C exhibits excellent performance in ORR, the low duration, high cost, and poor methanol tolerance seriously restrict its sustainable development and application. TinO2n−1 (3 ≤ n ≤ 10) is a series of titanium sub-oxide materials with excellent electrical conductivity, electrochemical activity, and stability, which have been widely applied in the field of energy storage and catalysis. Herein, we design and synthesize Ti4O7/Ti3O5 (T4/T3) dual-phase nanofibers with excellent ORR catalytic performance through hydrothermal growth, which is followed by a precisely controlled calcination process. The H2Ti3O7 precursor with uniform size can be first obtained by optimizing the hydrothermal growth parameters. By precisely controlling the amount of reducing agent, calcination temperature, and holding time, the T4/T3 dual-phase nanofibers with uniform morphology and coherent interfaces can be obtained. The orientation relationships between T4 and T3 are confirmed to be , , and , respectively, based on comprehensive transmission electron microscopy (TEM) investigations. Furthermore, such dual-phase nanofibers exhibit the onset potential and half-wave potential of 0.90 V and 0.75 V as the ORR electrocatalysts in alkaline media, respectively, which illustrates the excellent ORR catalytic performance. The rotating ring-disk electrode (RRDE) experiment confirmed the electron transfer number of 3.0 for such catalysts, which indicates a mixture of two electron and four electron transfer reaction pathways. Moreover, the methanol tolerance and cycling stability of the catalysts are also investigated accordingly.
Highlights
The development of new clean energy technologies is imperative in recent years due to the serious energy crisis and environmental pollution [1,2,3]
The filling amount of the reactant as well as the reaction temperature were modified from 50% to 80% and 160 ◦ C to 200 ◦ C to illustrate these effects on the growth morphology of the precursor
A higher filling solubility andtothe pH value, and, thereby, affectswhich the reaction and theofmorphology of the amount leads a larger pressure inside the reactor, leads torate the change reactants solubility products
Summary
The development of new clean energy technologies is imperative in recent years due to the serious energy crisis and environmental pollution [1,2,3]. As the two most promising new energy technologies, fuel cells and metal-air batteries possess excellent safety and sustainability, which has attracted more attention in recent years [4,5] These two devices enjoy the same cathodic oxygen reduction reaction: O2 + 4H+ + 4e− → 2H2 O , which is the key reaction to improve the performance and energy conversion efficiency [6,7,8]. Materials 2020, 13, 3142 to the formation of more intermediates, high reaction activation energy, slow kinetic rate, and more In this case, the efficiency of the oxygen reduction reaction becomes a big challenge affecting the performance of the energy conversion devices [9,10]. Plenty of research studies have been carried out on the design and synthesis of various Oxygen Reduction Reaction (ORR) electrocatalysts in recent years [11,12,13,14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
