Fabrication of Highly Textured 2D SnSe Layers with Tunable Electronic Properties for Hydrogen Evolution.

Qianyu Zhou,Mengya Wang,Yong Li,Qi Wu,Yanfang Liu,Shifeng Wang,Yuanfu Chen

doi:10.3390/molecules26113319

Abstract

Hydrogen is regarded to be one of the most promising renewable and clean energy sources. Finding a highly efficient and cost-effective catalyst to generate hydrogen via water splitting has become a research hotspot. Two-dimensional materials with exotic structural and electronic properties have been considered as economical alternatives. In this work, 2D SnSe films with high quality of crystallinity were grown on a mica substrate via molecular beam epitaxy. The electronic property of the prepared SnSe thin films can be easily and accurately tuned in situ by three orders of magnitude through the controllable compensation of Sn atoms. The prepared film normally exhibited p-type conduction due to the deficiency of Sn in the film during its growth. First-principle calculations explained that Sn vacancies can introduce additional reactive sites for the hydrogen evolution reaction (HER) and enhance the HER performance by accelerating electron migration and promoting continuous hydrogen generation, which was mirrored by the reduced Gibbs free energy by a factor of 2.3 as compared with the pure SnSe film. The results pave the way for synthesized 2D SnSe thin films in the applications of hydrogen production.

Highlights

With the increase in CO2 emissions due to the use of traditional energy sources such as coal-fired electricity and oil-powered cars, the global warming leading to the sea level rise, glaciers melting, and frequent extreme weather has become an issue of increasing concern all over the world
Was coined in 2005 [1,2], which referred to an equilibrium between the CO2 emissions in the atmosphere and the removal or capture of CO2 from the atmosphere generating net zero emissions
SnSe films were deposited on mica substrates using the molecular beam epitaxy (MBE)

Summary

Introduction

With the increase in CO2 emissions due to the use of traditional energy sources such as coal-fired electricity and oil-powered cars, the global warming leading to the sea level rise, glaciers melting, and frequent extreme weather has become an issue of increasing concern all over the world. To address this challenge, the concept of “carbon neutrality”. Several effective strategies have been proposed to reduce the amount of CO2 emissions, such as planting more trees, encouraging use of renewable energy sources, improving energy efficiency, and developing clean transportation. To dissociate water molecules into hydrogen and oxygen by means of photoelectrochemical

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Discussion

Conclusion