Recent Advances in Earth‐Abundant Photocathodes for Photoelectrochemical Water Splitting

Abstract

The conversion of solar energy into hydrogen through photoelectrochemical (PEC) water splitting is an attractive way to store renewable energy. Despite the intriguing concept of solar hydrogen production, efficient PEC devices based on earth-abundant semiconductors should be realized to compete economically with conventional steam reforming processes. Herein, recent milestones in photocathode development for PEC water splitting, particularly in earth-abundant semiconductors, in terms of new techniques for enhancing performance, as well as theoretical aspects, are highlighted. In addition, recent research into newly emerging low-cost p-type semiconductors in the PEC field, such as Cu BaSn(S,Se) and Sb Se , are scrutinized and the advantages and disadvantages of each material assessed.

Rationally Designed Heterojunction on a CuBi2O4 Photocathode for Improved Activity and Stability during Photoelectrochemical Water Reduction

“…Although CBO possesses the above merits, the photocathode materials based on CBO for HER have relatively few been reported. However, the disadvantages of the low light absorption efficiency, high charge‐recombination rate and easy to photocorrosion still limit their PEC performance . So far, some reports have explored to ameliorate the shortcomings of CBO, such as the change of morphology, the doping of other elements, the formation of heterojunction and the modification of some co‐catalysts or precious metals .…”

“…However, the disadvantages of the low light absorption efficiency, high charge-recombination rate and easy to photocorrosion still limit their PEC performance. [9][10] So far, some reports have explored to ameliorate the shortcomings of CBO, such as the change of morphology, [11] the doping of other elements, [12] the formation of heterojunction [13] and the modification of some co-catalysts or precious metals. [14] The above research results significantly improved HER performance of the CBO-based photocathode, due to the improvement of separation efficiency of photogenerated carriers.…”

Directly Photoexcited Oxides for Photoelectrochemical Water Splitting

“…Its relativelyn arrow E G of 1.9 eV enables the absorption of most of the visible-light spectrum.B ecause the CB and VB lie below and above the hydrogen evolution and oxygen Fermi levels,r espectively,i ti sc onsidered one of the promising p-PE materials. Notwithstanding this, the aforementioned comprehensive work revealed the [14] and 2018, American Chemical Society. [123] However, this material has not demonstrated as atisfying performance due to strongb ulk recombination.…”

“…In this flourishing field, numerous reviews have been published on differenta spects, such as materials, [5][6][7][8] protection strategies, [9][10][11] and practical applications. [12,13] Reviews on oxide photoelectrodes (PEs) are among them,w hich focus on photocathodes, materials, and cocatalysts, [6,7,14,15] whereas this review intends to sort the most recent progress in oxide PEs by cell configurations, which are defined by charge-separationt ypes. An abbreviated terminology for the facilitated description of various PEC types is introduced herein.…”

CoP/N‐Doped Carbon Nanowire Derived from Co‐Based Coordination Polymer as Efficient Electrocatalyst toward Oxygen Evolution Reaction

“…Splitting water into H 2 and O 2 is an attractive hydrogen production technology. The methods include electrochemical, photocatalytic, and photoelectrocatalytic water splitting. Compared with photocatalytic and photoelectrocatalytic water splitting, electrocatalytic water splitting can efficiently achieve continuous production of H 2 and O 2 .…”