One-pot hydrothermal synthesis of uniform β-MnO2 nanorods for nitrite sensing

A simple hydrothermal method was developed for the synthesis of uniform single-crystal beta-MnO2 nanorods only using potassium permanganate and sodium nitrite in acidic solution, without any seed or template. The as-prepared beta-MnO2 nanorods have the average diameter of 300 +/- 20 nm and a length up to 1.2 +/- 0.2 mu m. Moreover, the effects of pH, temperature, and reactant molar ratios on the morphology of the final product were studied in detail. In addition, the catalytic ability of the as-prepared beta-MnO2 nanorods was tested for the electrooxidation of nitrite. The resulting sensor showed a wide linear range from 0.29 mu M to 26.09 mM (R = 0.9986), high sensitivity (1.21 mu A mM(-1), S/N = 3), low detection limit (0.29 mu M), and fast response (less than 5 s). (C) 2011 Elsevier Inc. All rights reserved.