Ni-Activated and Ni-P-Activated Porous Titanium Carbide Ceramic Electrodes as Efficient Electrocatalysts for Overall Water Splitting.

Abstract

Developing electrocatalysts based on transition-metal carbides that can be utilized for commercial water splitting is a challenging endeavor. To address this challenge, we employed a novel approach that merged phase-inversion tape-casting and sintering, subsequently implementing a simple and efficient electrodeposition process, to synthesize Ni-activated and Ni-P-activated titanium carbide (Ni/TiC, Ni-P/TiC) ceramic electrodes as water splitting catalytic cathodes and anodes. These self-supported Ni/TiC and Ni-P/TiC electrodes are binder-free with abundant finger-like pores, which contribute to the formation of highly conductive skeleton and more exposed active sites for direct water splitting. These catalysts exhibit outstanding performance, superior to many reported bifunctional nickel-based catalysts supported on other substrates. Moreover, the exceptional electrocatalytic performance of the Ni/TiC and Ni-P/TiC catalysts is attributed to the synergistic effect between Ni oxides (phosphides) and TiC, as revealed by density functional theory (DFT) calculations. This self-template strategy paves the way for fabricating industrially applicable electrodes to generate hydrogen and oxygen through water splitting.