Abstract

An ultrathin FeOOH cocatalyst is deposited on α-Fe2O3 photoanodes in a simple room temperature immersion process for efficient photoelectrochemical (PEC) water splitting. The prepared FeOOH/Fe2O3 photoanode has a photocurrent density of up to 2.4 mA/cm2 at 1.23 V versus reversible hydrogen electrode (RHE), and the photocurrent density is increased by about 160% compared to the bare Fe2O3 of 1.55 mA/cm2. An obvious cathodic shift of the photocurrent onset potential from 0.661 to 0.582 V was also observed, and excellent stability was maintained with almost no deterioration for 5 h. The enhanced PEC performance is attributed to the decrease of the interfacial resistance between electrode and electrolyte and the increase of the injection efficiency of holes in Fe2O3.

Highlights

  • Solar-driven photoelectrochemical (PEC) water splitting has been a promising method to translate solar energy to chemical fuels, which has been widely concerned and studied [1]

  • FeOOH/Fe2O3 photoanodes were formed by the room temperature impregnation method

  • The Fe2O3 photoanode was immersed in 25 ml solution of 0.075 M FeCl3·6H2O (Shanghai Hushi, 99.99%) and 0.15 M CO(NH2)2 (Shanghai Hushi, 99%) for varying durations (1 h, 2 h, and 3 h) at room temperature (25°C)

Read more

Summary

Introduction

Solar-driven photoelectrochemical (PEC) water splitting has been a promising method to translate solar energy to chemical fuels, which has been widely concerned and studied [1]. As a promising candidate material for PEC water splitting, α-Fe2O3 has advantages such as excellent stability, economical, nontoxic, appropriate band gap (~2.1 eV), high theoretical photocurrent value of 12.5 mA/cm, and nearly 15.8% solar-to-hydrogen efficiency (STH) [9]. OEC deposition can effectively accelerate the oxidation rate of water, thereby reducing the onset potential of α-Fe2O3. The formed FeOOH cocatalyst effectively decreases the interfacial resistance between the electrode and the electrolyte of Fe2O3 photoanodes and increases the injection efficiency of holes. This allows the holes to travel faster from the Fe2O3 photoanode surface to the electrolyte, the efficient water oxidation reaction occurs at the interface of electrode and electrolyte. A cathodic shift of onset potential is about 80 mV from 0.66 to 0.58 V and excellent photostability in 5 h

Experimental
Results and Discussion
Conclusions

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.