Low temperature aqueous synthesis of highly dispersed Co3O4 nanocubes and their electrocatalytic activity studies

We report here a simple approach to the synthesis of highly dispersed Co3O4 nanocubes in higher yield by aqueous precipitation method at low temperatures (70-90 degrees C). The nanosized Co3O4 powders were directly achieved from Co(II) aqueous solution under alkaline and oxidizing conditions. TEM results indicate that the as-prepared Co3O4 has a cubic nanostructure with uniform size of about 20nm and narrow size distribution. Powder X-ray diffraction (XRD) and infrared spectrum (IR) results show that the samples are Co3O4 in spinel structure. The objective Co3O4 nanocubes can be achieved in a wide range of experimental parameters, which can be preserved as stable suspension in distilled water or ethanol for several months with no obvious change. Appropriate reaction time and temperature should be controlled to get better crystallized Co3O4 nanocubes with perfect cubic appearance and good dispersibility. It is essential to achieve cubic-like Co3O4 particles by using ammonia as precipitator. The as-prepared Co3O4 nanocubes, combined with PbO2 as electrodes, extend improved electrocatalytic activities and decreased oxygen evolution potential in electrochemical reactions, so they can be used as potential electrode materials or electrocatalytic materials. This facile method for the synthesis of Co3O4 nanocubes is a simple and general process without any seed, catalyst, or template, thus it is promising for large-scale and low-cost production of Co3O4 with high-quality. (C) 2010 Elsevier B.V. All rights reserved.