Fabricating S-scheme Sb 2 S 3 @CdSe x S 1- x quasi-one-dimensional heterojunction photoanodes by in-situ growth strategy towards photoelectrochemical water splitting

Nowadays, energy and environmental problems are becoming increasingly prominent in society, the development of clean and environmentally friendly energy is in line with the construction of ecological civilization and energy, which have attracted the attention of many researchers over the past decades. Narrow band gap semiconductor Sb 2 S 3 is widely used in the area of solar cells because of its high light absorption coefficient and suitable bandgap width. However, numerous deep -level defects provide plentiful photogenerated carrier recombination sites, which restricts the improvement of photoelectrochemical properties seriously. In this work, S -scheme Sb 2 S 3 @CdSe x S 1- x core -shell quasi -one-dimensional heterojunction photoanodes were prepared on the FTO substrate by a two-step vapor transport deposition (VTD) method, chemical bath deposition (CBD) and in -situ selenization method. The results showed that CdSe x S 1- x nanoparticles (NPs) were tightly coated on the Sb 2 S 3 nanorods (NRs). The photocurrent density of the Sb 2 S 3 @CdSe x S 1- x photoanodes was 1.61 mA cm -2 under 1.23 V RHE . Compared with the Sb 2 S 3 photoanodes (0.61 mA cm -2 ), Sb 2 S 3 @CdSe x S 1- x photoanodes obtained a 2.64 -fold improvement, and the dark current was effectively reduced. It showed excellent stability and fast photocurrent response in a 600 s optical stability test. It was concluded that: (1) The charge transfer mechanism of the S -scheme can avoid the problem of high recombination rate of photogenerated charge carriers due to the defects of Sb 2 S 3 effectively, and realized spatial separation of photogenerated carriers. (2) The [ hk 1] oriented Sb 2 S 3 NRs and the formed quasi -one-dimensional heterostructures promote efficient carrier transport. (3) The introduction of Se effectively regulated the band structure of CdS, slowed down the photocorrosion of S, and improved the stability of the photoelectrodes significantly. (c) 2024 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.