Durability Testing of Photoelectrochemical Hydrogen Production under Day/Night Light Cycled Conditions

Abstract

This work investigates long‐term photoelectrochemical hydrogen evolution (82 days) in 1 M HClO4 using a TiO2:H protected crystalline Si‐based photocathode with metal‐oxide‐semiconductor (MOS) junctions. It is shown that day/night cycling leads to relatively rapid performance degradation while the photocurrent under the continuous light condition is relatively stable. We observed that the performance loss is mainly due to contamination of the catalytically active surface with carbonaceous material. By ultraviolet (UV) light exposure, we also observed that the activity can be restored, most likely due to photocatalytic degradation of organic compounds by the UV light excited TiO2 protection layer.

Design principles for efficient photoelectrodes in solar rechargeable redox flow cell applications

“…In the bare Si case, obtaining a reliable result is rather challenging due to surface deactivation caused by silane or oxide formation in the electrolyte (Fig. 2a), as described in previous studies 1,2 . It is noteworthy that the surface of the Si was chemically cleaned upon any electrochemical analysis by using a 3 M H 2 SO 4 solution in order to remove the native oxide layer.…”

“…1a, the combination of the carbon with the TiO 2 resulted in a substantial negative shift in V on (~0.9 V). Further, the TiO 2 film with co-catalysts showed an efficient charge transfer performance, which is proven for water reduction studies 1,16 ; thus, this unexpected poor activity in ferricyanide reduction cannot be explained by a conductivity investigation.…”

“…1) in order to study the electrochemical reduction reactivity of the various conducting materials sputtered on highly doped silicon (c-Si) substrate (see inset). For a few samples, the TiO 2 protection layer was sputtered as described elsewhere 1,14 prior to the conducting layer deposition (Fig. 1b).…”

“…he increasing demand for integration of renewable energies into the grid calls for an energy storage system (ESS) that can provide a safe and effective solution to the inherent nature of temporal intermittencies, like sunlight. In this context, the utilisation of solar energy through photoelectrochemical (PEC) processes-including solar water splitting 1,2 and other types of solar fuel (CO 2 or N 2 reduction) 3,4 -has been regarded as being particularly attractive for storing solar energy. However, the sluggish kinetics (e.g.…”

“…Even though the initial solar redox storage cell concept was demonstrated in 1976 by Hodes et al 13 , most demonstrations have been reported rather recently 14,15 in the wake of PEC materials which have been utilised for solar-fuel production 1,2 . Unlike conventional PEC fuel conversion processes, SRFB offers flexibility with respect to redox potential, which results in an unprecedented wide selection of band-gap (E g ) of PEC materials.…”