Gradient heterostructured titanium nitride/carbide for enhanced stability and efficiency in hydrogen evolution reaction

초록

The development of efficient and durable multifunctional water splitting catalysts is essential for advancing hydrogen production in the energy industry. Herein, Ti-based carbide and nitride (Ti-C/N-(x), where x refers to the C/N atomic ratio) heterostructures with a controlled compositional gradient were synthesized via chemical vapor deposition, forming a structure with both heterostructure and vertical C/N gradients. Among the synthesized samples, Ti-C/N-(1.2) with a C-rich surface and a distinct vertical gradient was identified as the optimal composition in terms of electrochemical hydrogen evolution and durability. The combined effect of the heterostructure and compositional gradient was most effectively realized in Ti-C/N-(1.2). Moreover, Ti-C/N-(1.2) demonstrated remarkable durability for hydrogen evolution reaction, maintaining stability for 48 h at a current density of -100 mA cm- 2 in universal pH electrolytes. Importantly, a two-electrode electrolysis system utilizing a Ti-C/N-(1.2) cathode achieved outstanding long-term stability, operating for 1170 h at a current density of -100 mA cm- 2 in artificial seawater solution. These results establish Ti-C/N-(x) as a promising electrocatalyst for sustainable hydrogen production, demonstrating exceptional durability and efficiency across diverse electrochemical applications.

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