General Characterization Methods for Photoelectrochemical Cells for Solar Water Splitting

Abstract

Photoelectrochemical (PEC) water splitting is a very promising technology that converts water into clean hydrogen fuel and oxygen by using solar light. However, the characterization methods for PEC cells are diverse and a systematic introduction to characterization methods for PEC cells has rarely been attempted. Unlike most other review articles that focus mainly on the material used for the working electrodes of PEC cells, this review introduces general characterization methods for PEC cells, including their basic configurations and methods for characterizing their performance under various conditions, regardless of the materials used. Detailed experimental operation procedures with theoretical information are provided for each characterization method. The PEC research area is rapidly expanding and more researchers are beginning to devote themselves to related work. Therefore, the content of this Minireview can provide entry-level knowledge to beginners in the area of PEC, which might accelerate progress in this area.

Bismuth Vanadate with Electrostatically Anchored 3D Carbon Nitride Nano‐networks as Efficient Photoanodes for Water Oxidation

“…To gain a deeper insight into the interfacial charge‐transfer behavior, electrochemical impedance spectroscopy (EIS) measurements were carried out under light illumination at the applied potential bias of 0.7 V (vs. RHE). In the Nyquist graph (Figure e), the nanocomposite of CNNW/BVO shows a smaller semicircle radius compared with pristine BVO, which represents a more efficient charge separation . Furthermore, CNNW/BVO‐FN exhibits the smallest semicircle radius among all photoanodes, suggesting a fastest interfacial charge transfer in the CNNW/BVO‐FN heterojunction, which is consistent with the photocurrent and CTE results .…”

Green Synthetic Fuels: Renewable Routes for the Conversion of Non-Fossil Feedstocks into Gaseous Fuels and Their End Uses

“…The electrolyte is an aqueous solution with suitable ionic conductivity and inert in contact with the photoanode. For electrodes that need an acidic electrolyte, H 2 SO 4 is used; for alkaline electrolytes, KOH and NaOH are used; Na 2 SO 4 , K 2 SO 4 or KH 2 PO 4 /K 2 HPO 4 are used for neutral electrolytes [303]. Since H 2 and O 2 generation occurs on different electrodes, products are collected separately, avoiding the need of post-treatments.…”

“…In the external biased configuration, a photocurrent is The solar energy conversion efficiency of photocatalytic water-splitting reactions depends on light absorption, charge separation and transfer, recombination processes and electrocatalytic activity of the semiconductor anode [309]. The solar-to-hydrogen (STH) conversion efficiency is defined as the ratio of the chemical energy of hydrogen generated to the solar energy input and is a function of semiconductor bandgap [303]. In Figure 12a is displayed the theoretical maximum efficiency for a variety of semiconductor materials, the upper limit for a single material reaches 16% when the bandgap is near 2.0 eV [309].…”

Hydrogen evolution by a photoelectrochemical cell based on a Cu2O-ZnO-[FeFe] hydrogenase electrode

“…The active area is determined to 0.25 cm 2 by a black tape mask mentioned before. All the potentials were converted into RHE based by the equation: ERHE = E(Ag/AgCl)SHE +0.059pH + E(Ag/AgCl) [31].…”