Recent Progress in the Surface Modification of Photoelectrodes toward Efficient and Stable Overall Water Splitting

Abstract

Photoelectrochemical (PEC) water splitting using a combination of a photocathode and photoanode is one of the most promising methods of producing hydrogen from water employing sunlight. Recent reports have shown that surface modification of the photoelectrodes dramatically improves their PEC performance. Bare photoelectrodes often exhibit insufficient depletion regions, undesired surface states and/or degradation due to photocorrosion. It has been demonstrated that surface modifications can tune the flat-band potentials, band-edge potentials, surface states and chemical stabilities of these electrodes and thus improve quantum efficiency, onset potential and durability. This review describes in detail the various surface modification materials that have been developed to date, and the functions of these modifiers. This information is expected to provide guidelines for the future development of photoelectrodes capable of highly efficient and stable PEC water splitting.

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

“…In general, a photoanode consisting of a single semiconductor cannot satisfy the required performance of either photocurrent or conversion efficiency to meet commercial application due to their intrinsic limitations on performance and defects on properties, such as low solar light absorption, poor charge‐carrier transportation, and severe photocorrosion under illumination ( Table 2 ). Therefore, effective strategies such as surface modifications need to be applied to improve these properties of photoanodes. What is noteworthy is that designing functional photoanodes incorporated with cocatalysts to offset the drawbacks of single material is one of the states of art in PEC water splitting …”

Constructing Chemical Interaction between Hematite and Carbon Nanosheets with Single Active Sites for Efficient Photo‐Electrochemical Water Oxidation

“…In addition, the introduction of OECs in PEC system are mainly emphasized to facilitate surface water oxidation reaction kinetics and passivate surface defects for reduced charge recombination. [ 29 ] Nevertheless, the effect of interfacial interaction at the junction of semiconductor and OECs, which plays a crucial role for the charge transfer to the active sites on OECs, are often ignored but should be profoundly investigated, especially when the OECs are loaded with direct‐deposition method. The interaction between two different components can be divided into the physical adsorption and chemical coupling.…”

A Room‐Temperature Postsynthetic Ligand Exchange Strategy to Construct Mesoporous Fe‐Doped CoP Hollow Triangle Plate Arrays for Efficient Electrocatalytic Water Splitting

“…Electrochemical water splitting, involving two half reactions of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), has been widely explored as a promising approach to obtain clean renewable energy . To cut the use of noble‐metal‐based electrocatalysts such as IrO 2 /RuO 2 for OER and Pt for HER, enormous efforts have been afforded to expedite the thermodynamically unfavorable procedure of OER and HER at low overpotentials by using cost‐efficient and earth‐abundant electrocatalysts . As one type of non‐noble metal compounds, transition metal‐based phosphides (TMPs) have been identified as high activity and stability electrocatalysts for water splitting .…”