Efficient Photoelectrochemical Water Oxidation on Hematite with Fluorine-Doped FeOOH and FeNiOOH as Dual Cocatalysts.

An effective cocatalyst is usually required to improve the performance of photoelectrochemical (PEC) water splitting catalysts. A fluorine-doped FeOOH (F:FeOOH) cocatalyst on a hematite photoanode was used to lower the onset potential by 140 mV and significantly improve the PEC performance. Moreover, a more effective dual cocatalytic system was prepared by subsequent loading of a FeNiOOH cocatalyst, which resulted in a further decrease of the onset potential by 270 mV. The final onset potential of the Fe2 O3 /F:FeOOH/FeNiOOH photoanode was lowered to 0.45 V versus the reversible hydrogen electrode (RHE), which is one of the lowest onset potential values ever reported for hematite photoanodes. The photocurrent also dramatically increased by a factor of approximately 3 to 0.9 mA cm-2 at 1.0 V versus RHE. Based on the structural, chemical, and electrochemical impedance spectroscopy characterization, the enhanced performance was attributed to the F:FeOOH overlayer, which reduced the surface recombination and accelerated the oxygen evolution reaction activity, and the FeNiOOH cocatalyst, which further enhanced the reaction kinetics. The facile preparation of the F:FeOOH cocatalyst and the design of the dual cocatalytic system will allow the development of high-performance hematite photoanodes.

Deng J ，Zhang Q ，Feng K ，Lan H ，Zhong J ，Chaker M ，Ma D ... -  《-》

Loading the FeNiOOH cocatalyst on Pt-modified hematite nanostructures for efficient solar water oxidation.

Deng J ，Lv X ，Zhang H ，Zhao B ，Sun X ，Zhong J ... -  《-》

Boosting Hole Transfer in the Fluorine-Doped Hematite Photoanode by Depositing Ultrathin Amorphous FeOOH/CoOOH Cocatalysts.

Wang T ，Long X ，Wei S ，Wang P ，Wang C ，Jin J ，Hu G ... -  《-》

Surviving High-Temperature Calcination: ZrO(2) -Induced Hematite Nanotubes for Photoelectrochemical Water Oxidation.

Nanotubular Fe2 O3 is a promising photoanode material, and producing morphologies that withstand high-temperature calcination (HTC) is urgently needed to enhance the photoelectrochemical (PEC) performance. This work describes the design and fabrication of Fe2 O3 nanotube arrays that survive HTC for the first time. By introducing a ZrO2 shell on hydrothermal FeOOH nanorods by atomic layer deposition, subsequent high-temperature solid-state reaction converts FeOOH-ZrO2 nanorods to ZrO2 -induced Fe2 O3 nanotubes (Zr-Fe2 O3 NTs). The structural evolution of the hematite nanotubes is systematically explored. As a result of the nanostructuring and shortened charge collection distance, the nanotube photoanode shows a greatly improved PEC water oxidation activity, exhibiting a photocurrent density of 1.5 mA cm-2 at 1.23 V (vs. reversible hydrogen electrode, RHE), which is the highest among hematite nanotube photoanodes without co-catalysts. Furthermore, a Co-Pi decorated Zr-Fe2 O3 NT photoanode reveals an enhanced onset potential of 0.65 V (vs. RHE) and a photocurrent of 1.87 mA cm-2 (at 1.23 V vs. RHE).

Li C ，Li A ，Luo Z ，Zhang J ，Chang X ，Huang Z ，Wang T ，Gong J ... -  《-》

Deposition of FeOOH Layer on Ultrathin Hematite Nanoflakes to Promote Photoelectrochemical Water Splitting.

Zhang W ，Zhang Y ，Miao X ，Zhao L ，Zhu C ... -  《Micromachines》