Highly Conformal Deposition of an Ultrathin FeOOH Layer on a Hematite Nanostructure for Efficient Solar Water Splitting

Abstract

An ultrathin (ca. 2 nm) amorphous FeOOH overlayer was deposited conformally on a hematite nanostructure by a simple solution-based precipitation method, to generate an oxygen evolution cocatalyst for efficient solar water splitting. This uniform and highly conformal coating of the ultrathin metal oxyhydroxide is rare and is distinguished from the layers prepared by other conventional methods. With the FeOOH overlayer as the cocatalyst, the water oxidation photocurrent of hematite increased by a factor of approximately two and the onset potential shifted in the cathodic direction by 0.12 V under 1 sun illumination. The enhanced performance was attributed to the improved water oxidation kinetics and the passivation of the surface states of the hematite.

Ir-phosphate cocatalyst for photoelectrochemical water oxidation using α-Fe2O3

“…Similarly, photoelectrodeposited Co-Pi caused 170 mV improvement 29 whereas FeOOH cocatalyst shied the onset potential by 120 mV. 30 It is also reported that photo or electrochemical deposition of Nioxides or Co-oxides on hematite could lower the required bias voltage by 100-300 mV. (Fig.…”

Rational Design and Construction of Cocatalysts for Semiconductor‐Based Photo‐Electrochemical Oxygen Evolution: A Comprehensive Review

“…[33,73,101,[171][172][173][174][175][176] It has potential advantages such as feasible synthesis, well stability, and resource abundancy. [33,73,101,[171][172][173][174][175][176] It has potential advantages such as feasible synthesis, well stability, and resource abundancy.…”

Metal–Organic Framework Derived Co3O4/TiO2/Si Heterostructured Nanorod Array Photoanodes for Efficient Photoelectrochemical Water Oxidation

“…[18,19] Therefore, designing composited photoanodes with proper band-gap energy structure is considered to be a promising route to overcome these limitations induced poor PEC performance. [8,32,33] Recently, the outstanding OER performance Water Splitting Particularly, benefiting from the outstanding visiblelight response performance and carrier mobility within silicon, it has long been regarded as the most suitable material to build the solar energy conversion device.…”

“…[26] As the conduction band (CB) of silicon is more negative than most of the common MO semiconductors (e.g., TiO 2 , [27,28] WO 3 ), [29] silicon can bring better electron reduction kinetics on the counter electrode. [8,32,33] Recently, the outstanding OER performance Water Splitting [23,31] In this regard, constructing MO/Si heterostructured photoanode is proposed to overcome the potential shortcomings of both MO and silicon simultaneously.…”

“…Particularly, benefiting from the outstanding visiblelight response performance and carrier mobility within silicon, it has long been regarded as the most suitable material to build the solar energy conversion device. [8,32,33] Recently, the outstanding OER performance Water Splitting [30] However, it is not efficient to directly use only silicon as anode for PEC water oxidation due to the valence band (VB) of silicon is higher than the water oxidation potential.…”