NanoCOT: Low-Cost Nanostructured Electrode Containing Carbon, Oxygen, and Titanium for Efficient Oxygen Evolution Reaction

Zhichao Shan; Panikar Sathyaseelan Archana; Gang Shen; Arunava Gupta; Martin G Bakker; Shanlin Pan

doi:10.1021/jacs.5b05367

NanoCOT: Low-Cost Nanostructured Electrode Containing Carbon, Oxygen, and Titanium for Efficient Oxygen Evolution Reaction

J Am Chem Soc. 2015 Sep 23;137(37):11996-2005. doi: 10.1021/jacs.5b05367. Epub 2015 Sep 15.

Authors

Zhichao Shan^{1

2}, Panikar Sathyaseelan Archana^{1

2}, Gang Shen³, Arunava Gupta^{1

2

4}, Martin G Bakker¹, Shanlin Pan^{1

2}

Affiliations

¹ Department of Chemistry, The University of Alabama , Tuscaloosa, Alabama 35487-0336, United States.
² Center for Materials for Information Technology, The University of Alabama , Tuscaloosa, Alabama 35487-0209, United States.
³ Department of Electrical and Computer Engineering, The University of Alabama , Tuscaloosa, Alabama 35487-0200, United States.
⁴ Department of Chemical and Biological Engineering, The University of Alabama , Tuscaloosa, Alabama 35487-0203, United States.

PMID: 26340536
DOI: 10.1021/jacs.5b05367

Abstract

Developing high-efficiency, durable, and low-cost catalysts based on earth-abundant elements for the oxygen evolution reaction (OER) is essential for renewable energy conversion and energy storage devices. In this study, we report a highly active nanostructured electrode, NanoCOT, which contains carbon, oxygen, and titanium, for efficient OER in alkaline solution. The NanoCOT electrode is synthesized from carbon transformation of TiO2 in an atmosphere of methane, hydrogen, and nitrogen at a high temperature. The NanoCOT exhibits enhanced OER catalytic activity in alkaline solution, providing a current density of 1.33 mA/cm(2) at an overpotential of 0.42 V. This OER current density of a NanoCOT electrode is about 4 times higher than an oxidized Ir electrode and 15 times higher than a Pt electrode because of its nanostructured high surface area and favorable OER kinetics. The enhanced catalytic activity of NanoCOT is attributed to the presence of a continuous energy band of the titanium oxide electrode with predominantly reduced defect states of Ti (e.g., Ti(1+), Ti(2+), and Ti(3+)) formed by chemical reduction with hydrogen and carbon. The OER performance of NanoCOT can also be further enhanced by decreasing its overpotential by 150 mV at a current density of 1.0 mA/cm(2) after coating its surface electrophoretically with 2.0 nm IrOx nanoparticles.