MoS2-supported on free-standing TiO2-nanotubes for efficient hydrogen evolution reaction

The electrochemical production of hydrogen is a promising and flexible approach towards the conversion of intermittent renewable energy sources into clean chemical fuel. However, low-cost, efficient, and durable electrocatalysts are yet to be developed to attain economies of scale in hydrogen generation. In this study, we fabricated highly ordered free-standing TiO2 nanotube arrays (TiO2-NTs), by simply anodizing Ti foils. The tube length, diameter, wall thickness, and surface structure of the TiO2-NTs can be controlled by adjusting the anodization conditions. Subsequently, we synthesized and supported MoS2 layers on free-standing TiO2-NTs as an active material for the hydrogen evolution reaction (HER), using a slow evaporation method. The layers of MoS2 uniformly disperse on the entire surface of the TiO2-NTs composite. The electrochemical test shows that the MoS2-supported free-standing (MoS2/TiO2-NTs) system exhibits excellent HER performance in acidic media with a low overpotential at 10 mA cm(-2) (170 mV), as well as small Tafel slope (70 mV decade(-1)). Also, the MoS2/TiO2-NTs displays superior durability for HER after 5000 continuous potential cycles between -0.4 and +0.2 (V vs. RHE). Our results demonstrate the potential application of MoS2/TiO2-NTs composite for cost-effective electrochemical production of hydrogen. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.