Infrared-light-driven SiN3 monolayer photocatalytic hydrolysis: A first-principles investigation

Abstract

Although the immediate priority is to design low-price, non-poisonous hydrolytic photocatalysts, locating high-performance photocatalysts remains challenging. Herein, SiN3 monolayer with excellent stability was designed and comprehensively investigated by first-principles calculations. The results demonstrate that SiN3 monolayer displays ultra-high electron mobility of 7.41 × 104 cm2 V−1 s−1 and conspicuous anisotropy. Furthermore, the utilization of sunlight by SiN3 monolayer stretches to the infrared region with an optical absorption coefficient value ∼105 cm−1, which far exceeds classical photocatalyst MoS2. More particularly, the overpotential of SiN3 monolayer can operate as a driving force for spontaneous hydrogen evolution reaction without the external potential under solar radiation, which suggests that it is outstanding photocatalyst. Furthermore, strain engineering contributes to optical absorption of SiN3 monolayer, which is amplified by a 1.76-fold at 692 nm at just 4 % strain. The work not only reveals the prospective application of SiN3 monolayer in infrared-light-driven hydrolysis, but sheds some light on implementing large-scale solar hydrogen generation.