https://doi.org/10.15255/KUI.2022.050
Published: Kem. Ind. 72 (3-4) (2023) 179–186
Paper reference number: KUI-50/2022
Paper type: Original scientific paper
Download paper:  PDF

Photoelectrocatalytic Hydrogen Production Supported by Ascorbic Acid

D. Balaić, G. Antonije Oreški, G. Radić, H. Kušić, K. Perović and M. Kraljić Roković

Abstract

Photoelectrochemical hydrogen production combines electrochemistry and photocatalysis, resulting in sustainable hydrogen production. The process can be improved by the addition of hole scavengers, which reduce the recombination of electrons and holes, increasing the utilisation of solar radiation. Because of its low oxidation potential, ascorbic acid (AA) is an environmentally friendly and readily available hole scavenger. The commonly studied photocatalyst TiO₂ makes little utilisation of solar radiation energy due to its high energy gap of 3.2 eV. The metal sulphide SnS₂ attracts attention due to its low energy band gap of 2.2 eV, which allows the use of the visible region of the spectrum. In this work, the electrochemical characterisation of SnS₂ and TiO₂ photoanodes in NaCl solution in the presence and absence of AA was performed. The effect of AA on the photoresponse was investigated using the linear polarisation method and monitoring the open circuit potential. The results confirmed that SnS₂ and TiO₂ electrodes are photoactive, and that AA has good hole scavenging properties. Hydrogen production was performed at constant potentials of 0.6 and 1.35 V, respectively. TiO₂ exhibited higher photoactivity, thus producing more hydrogen at 0.6 V. On the other hand, at a potential of 1.35 V, most of the hydrogen produced was the result of an electrochemical reaction rather than a photoelectrochemical reaction, thus, a larger amount of hydrogen was produced with the SnS₂ electrode. The highest amount of hydrogen produced in this work was at 1.35 V for the SnS₂ electrode in an argon atmosphere and it was 0.799 ml h^–1 cm^–2.

This work is licensed under a Creative Commons Attribution 4.0 International License

Keywords

ascorbic acid, hydrogen, hole scavenger, photoelectrochemical hydrogen production, tin(IV) sulfide, titanium(IV) oxide