Noble-metal-free hexagonal wurtzite CdS nanoplates with exposed (110) and (112) crystal facets for efficient visible-light H2 production

Abstract

Hexagonal wurtzite CdS has been regarded as one of the most promising semiconductors for photocatalysis. However, its water splitting performance under visible-light irradiation is seriously limited due to the high charge carrier recombination. In order to solve this limitation, we facilely prepared 2D hexagonal wurtzite CdS nanoplates (HWCs) with exposed (110) and (112) crystal facets via a water bath strategy. The visible-light responsivity of the HWCs exhibited an obvious red shift and, accordingly, the band gap was narrowed from 2.31 to 2.12 eV. Besides, the HWCs showed an excellent visible-light H₂ evolution rate of ca. 6214.5 μmol h⁻¹ g⁻¹ without cocatalysts due to the enhanced charge carrier separation between the (110) and (112) crystal facets. Finally, a possible photocatalytic mechanism for HWCs was tentatively proposed. This work will be beneficial for designing and fabricating powerful mono-component photocatalysts.