Citation

Chang, Robin Yee Hui and Yeoh, Keat Hoe and Jiang, Junke and Chai, Soo See and Abdullahi, Yusuf Zuntu and Khong, Heng Yen and Lim, Thong Leng and Tuh, Moi Hua (2023) Forecasting the unrevealed surface-controlled photocatalytic water splitting in two-dimensional Ag2Se with ultrafast carrier mobility: a first-principles study. Catalysis Science & Technology, 13 (16). pp. 4813-4822. ISSN 2044-4753

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Abstract

It has been hypothesized that a thermodynamically feasible Ag2Se monolayer could be a potential candidate for photocatalytic water splitting. However, the present electronic structure knowledge is insufficient for forecasting and confirming the ultimate criterion of photocatalysis. Its wide band gap of around 2.70 eV is also non-ideal for photovoltaic conversion. These challenges are addressed herein using first-principles density functional theory (DFT) calculations to systematically probe the photocatalytic potential, light absorption coefficient, carrier mobility and carrier utilization efficiency of Ag2Se. To ascertain the spontaneity of the solar-to-hydrogen conversion, significant efforts have been made to calculate the energy barriers for the surface hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Fascinatingly, upon −6% compressive biaxial straining, the Ag2Se monolayer ingeniously combines all the desired characteristics for photocatalytic water-splitting activity, including a broader sunlight absorption region (∼105 cm−1), enhanced carrier mobility (∼105 cm2 V−1 s−1) and spontaneous catalytic pathways with relatively low triggering external potential, while retaining a direct band gap, good thermal stability and perfect band edge position. The corrected STH efficiency of ∼10% suggests commercial hydrogen production. This work provides valuable insights into the understanding of the catalytic mechanisms in the strain-modulated Ag2Se monolayer.

Item Type:	Article
Uncontrolled Keywords:	Photocatalysis; Absorbance; Monolayer; Water splitting; Electronic structure
Subjects:	Q Science > QD Chemistry > QD450-801 Physical and theoretical chemistry > QD701-731 Photochemistry
Divisions:	Faculty of Engineering and Technology (FET)
Depositing User:	Ms Nurul Iqtiani Ahmad
Date Deposited:	04 Sep 2023 07:14
Last Modified:	04 Sep 2023 07:14
URII:	http://shdl.mmu.edu.my/id/eprint/11670

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