Harnessing sunlight to photoelectrochemically split water and generate H2 holds great promise for future renewable energy production. However, to achieve commercial production of H2 via photoelectrochemical (PEC) devices, constraints such as cost, stability, and availability of resources must be overcome. To compete with today’s fossil fuel-based energy sources, precious metal catalysts must be replaced with catalysts that are inexpensive, Earth-abundant, and efficient and semiconductors must be modified to improve light absorption and reduce light reflectance. 1T-phase MoS2 (1T-MoS2) has gained popularity as a substitute for noble metal catalysts in PEC H2 evolution due to its conductivity, facile electrical transport, and high density of active sites. Additionally, the active site density may be increased further by intercalating 1T-MoS2 with transition metals to activate 1T-MoS2’s inert basal plane. Herein, zinc-doped 1T-MoS2 nanosheets are drop cast onto silicon nanowires and achieve 36.0 mA cm-2 photocurrent density at -171 mV vs RHE overpotential with a 41 mV dec-1 Tafel slope. Moreover, after 48 hours of electrolysis, 81.7% of their photocurrent density is maintained. Our work highlights the ability of Zn-doped 1T-MoS2 to not only compete with platinum metal catalysts for PEC H2 generation but also to significantly enhance the lifetime of silicon nanowires, bringing PEC devices one step closer to achieving large-scale applications of H2 generation.

Photoelectrochemical H2 generation via zinc-doped 1T-MoS2 on silicon nanowires

2019 Fall National Meeting

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