Photon-absorption-based explanation of ultrasonic-assisted solar photochemical splitting of water to improve hydrogen production. (2nd August 2018)

• Record Type: Journal Article
• Authors: Ziming, Cheng; Fuqiang, Wang; Huaxu, Liang; Shengpeng, Hu; Bo, Lin; Jianyu, Tan; Hongyang, Li
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 31(2018)
• Page Start: 14439
• Page End: 14450
• Publication Date: 2018-08-02
• Subjects: Hydrogen -- Water splitting -- Nanofluids -- Ultrasonic -- Solar photochemical -- Monte Carlo ray tracing; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.06.037
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The ultrasonic-assisted solar photochemical splitting of water had been explored in recent years to enhance hydrogen production efficiency. In this study, a photon-absorption-based study was conducted to investigate the mechanism of the ultrasonic-assisted solar photochemical splitting of water. An elaborate test bench for temperature-controlled, ultrasonic-assisted solar photochemical water splitting was designed, set up, and tested. A comparison of the hydrogen production between the ultrasonic-assisted and conventional solar photochemical splitting of water was carried out. The effective nanoparticle size before and after ultrasonic vibration, as well as after solar photocatalysis, was analyzed. Furthermore, the spectral absorptivity of the nanofluids before and after ultrasonic vibration, as well as after solar photocatalysis, was investigated by both experimental and numerical methods. The investigation indicated that the improved particle dispersion in the solution prepared by ultrasonication allowed the absorbance of more incoming sunlight. The amount of hydrogen produced by the ultrasonic-assisted hydrogen production was 3.45 times that of conventional solar photochemical splitting of water without pre-ultrasonicated. Besides, an effective spectral absorptivity coefficient was proposed as a modified measure of spectral absorptivity. In addition, the optimal particle diameter was optimized using the Monte Carlo ray tracing method to identify the best light absorption performance. Highlights: An test rig for ultrasonic-assisted solar photochemical water splitting is set up. Photon-absorption explanation of ultrasonic-assisted water splitting is introduced. H2 production, effective diameter with different pre-ultrasonicated time is tested. Effective spectral absorptivity coefficient is proposed to assess light absorption.