Current perspectives in engineering of viable hybrid photocathodes for solar hydrogen generation

Abstract

Photoelectrochemical water splitting represents an attractive technological solution to harvest and then store the solar energy which is abundant but intermittent. It can be achieved by employing a photoelectrochemical cell, also called an artificial leaf. In order to construct viable photoeclectrochemical cells, efforts are being dedicated to engineer robust and efficient photocathodes for solar H 2 generation and photoanodes for solar water oxidation reaction. In this article, we discuss on the recent achievements and current perspectives in engineering of viable hybrid photocathodes. The state of the art on the design of a hybrid photocathode, its performance as well as the current understanding of its mechanistic operation will be first described. We then discuss on the technical strategies that are currently being developed to enhance the robustness and performance of a hybrid photocathode.

Photoelectrochemical CO2 Reduction via Cu2O/CuFeO2 Hierarchical nanorods photocatalyst

“…Nanostructuring is essential to increase the photocatalytic activity of the photoelectrode. [6,10] According to several reported studies, Cu 2 O photocathodes that are not nanostructured exhibit low performance. [19,35] To improve the performance of the photoelectrode, the following problems must be solved by nanostructuring the photoelectrode.…”

“…[2,3] Among various candidate materials, Cu 2 O, which is a p-type semiconductor, has received much attention worldwide as a CO 2 RR photocatalyst. [4][5][6][7] It has a negative conduction band position and can thus produce photogenerated electrons that can overcome the activation energy barrier of the CO 2 RR. [8][9][10] Moreover, Cu 2 O has a bandgap of 1.9-2.2 eV, so it can efficiently absorb light from the solar spectrum.…”

“…[8,13,14] However, because monovalent copper oxide has reduction and oxidation redox potentials within the bandgap, copper oxide has serious stability problems as a photocatalyst. [6][7][8][9][10][11] Thus, further research on enhancing the stability of Cu 2 O-based photocatalysts is necessary. Recently, various studies have been conducted to improve the stability of the Cu 2 O photocatalyst.…”

“…[25,26] CuFeO 2 is capable of reducing carbon dioxide and is very suitable for forming a hierarchical structure with Cu 2 O because its band position is similar to that of Cu 2 O. [6,[27][28][29][30] According to several previous studies, CuFeO 2 /CuO composites have been fabricated as photocatalysts. However, they were produced in film form by electrodeposition or dip coating and suffered from a low current density.…”

“…However, because monovalent copper oxide has reduction and oxidation redox potentials within the bandgap, copper oxide has serious stability problems as a photocatalyst . Thus, further research on enhancing the stability of Cu 2 O‐based photocatalysts is necessary.…”