Hierarchical CdS Nanorod@SnO₂ Nanobowl Arrays for Efficient and Stable Photoelectrochemical Hydrogen Generation

Abstract

An efficient photoanode based on CdS nanorod@SnO nanobowl (CdS NR@SnO NB) arrays is designed and fabricated by the preparation of SnO nanobowl arrays via nanosphere lithography followed by hydrothermal growth of CdS nanorods on the inner surface of the SnO nanobowls. A photoelectrochemical (PEC) device constructed by using this hierarchical CdS NR@SnO NB photoanode presents significantly enhanced performance with a photocurrent density of 3.8 mA cm at 1.23 V versus a reversible hydrogen electrode (RHE) under AM1.5G solar light irradiation, which is about 2.5 times higher than that of CdS nanorod arrays. After coating with a thin layer of SiO , the photostability of the CdS NR@SnO NB arrays is greatly enhanced, resulting in a stable photoanode with a photocurrent density of 3.0 mA cm retained at 1.23 V versus the RHE. The much improved performance of the CdS NR@SnO NB arrays toward PEC hydrogen generation can be ascribed to enlarged surface area arising from the hierarchical nanostructures, improved light harvesting owing to the NR@NB architecture containing multiple scattering centers, and enhanced charge separation/collection efficiency due to the favorable CdS-SnO heterojunction.

Design of Heterostructured Hollow Photocatalysts for Solar‐to‐Chemical Energy Conversion

“…All these structural and compositional advantages of TiO 2 NR@NB arrays lead to enhanced PEC performance with a photocurrent density of 1.24 mA cm −2 at 1.23 V versus RHE under 100 mW cm −2 AM 1.5G irradiation (Figure F–H). To achieve better performance, materials responsive to visible light should be incorporated in the similar frame‐like structure . A nanosphere lithography method combined with hydrothermal growth was used to fabricate CdS NR@SnO 2 NB arrays, which exhibits a photocurrent density of about 3.8 mA cm −2 at similar conditions.…”

“…To achieve better performance, materials responsive to visible light should be incorporated in the similar frame-like structure. [97] A nanosphere lithography method combined with hydrothermal growth was used to fabricate CdS NR@SnO 2 NB arrays, which exhibits a photocurrent density of about 3.8 mA cm −2 at similar conditions.…”

Structure and Band Alignment Engineering of CdS/TiO2/Bi2WO6 Trilayer Nanoflake Array for Efficient Photoelectrochemical Water Splitting

“…[1][2] The rational design and fabrication of suitable photoanode materials are crucial for achieving efficient PEC water splitting system. [10][11][12][13][14][15][16][17] However, many studies have revealed that the PEC activity of pure CdS is severely limited because of the highly photogenerated carrier recombination. [6][7][8][9] The PEC application of CdS has been intensively studied.…”

“…[10][11][12][13][14][15][16][17] However, many studies have revealed that the PEC activity of pure CdS is severely limited because of the highly photogenerated carrier recombination. [27][28][29][30] For example, complex CdS architec-tures, such as three-dimensional (3D), [10,11] inverse opal arrays [12][13][14] and branched nanoarrays [15][16][17] have been fabricated. [18][19][20][21][22] The sulfide/sulfite ions as hole scavengers are always necessary for stable operation.…”

“…[6][7][8][9] The PEC application of CdS has been intensively studied. [10][11][12][13][14][15][16][17] However, many studies have revealed that the PEC activity of pure CdS is severely limited because of the highly photogenerated carrier recombination. Moreover, CdS suffers from serious photocorrosion under illumination because the photogenerated holes induce the self-oxidization of S 2À .…”