Highly Efficient and Robust MoS2 Nanoflake-Modified-TiN-Ceramic-Membrane Electrode for Electrocatalytic Hydrogen Evolution Reaction

Electrode design and fabrication are of major importance for hydrogen evolution reaction applications, as far as high-efficiency and low-cost production of hydrogen are concerned. This paper reports on a titanium-nitride-ceramic-membrane electrode modified by MoS2 nanoflakes. Porous TiN-ceramic membranes were fabricated by phase-inversion tape-casting, followed by pressureless sintering. The as-prepared TiN membranes contained straight finger-like pores with an average diameter of 80 mu m and smaller pores with an average diameter of 1-3 mu m. Then, MoS2 nanoflakes were perpendicularly, densely, and uniformly grown on the surface of the TiN grains through the one-pot hydrothermal method. The optimized MoS2/TiN membrane electrode displayed a low overpotential of 113 mV at 10 mA cm(-2), a Tafel slope of 78 mV dec(-1), a small charge transfer resistance of 1.44 Omega, and a high double-layer capacitance of 504 mF cm(-2). It also exhibited excellent stability with slight degradation after 80 h testing at an overpotential of 150 mV in 0.5 M H2SO4. The high conductivity of the TiN substrate, the similar chemical bonds, which favored the rapid electron transfer between MoS2 and TiN, the abundant exposed active sites of MoS2 nanoflakes, and the unique dual-pore structure resulted in the above superior electrocatalytic activity. The proposed successful utilization of conventional ceramic-membrane technology to prepare electrocatalysts based on membrane electrodes has potential for large-scale application in industrial hydrogen production.