Enhanced charge separation in CoOx@CdS core-shell hererostructure by photodeposited amorphous CoOx for high efficient hydrogen production

Abstract

The efficient spatial separation of charges is crucial for augmenting the photocatalytic efficacy. Herein, a CoOx@CdS core-shell hererostructure is fabricated by photodeposited amorphous CoOx cover the surface of 3D CdS for highly efficient photocatalytic hydrogen evolution (PHE). Amorphous CoOx extends the optical absorption range, suppresses the photocorrosion and enhance the specific surface area of CoOx@CdS. Consequently, the optimized 2%CoOx@CdS exhibits the superior PHE activity (16.30 mmol h-1 g-1) and outstanding photostability beyond 70 h was also obtained, which is 2.9 times greater than pure CdS. The markedly enhanced photoactivity of the optimized 2% CoOx@CdS is primarily due to the establishment of a core-shell architecture, wherein CoOx serves as a medium for the extraction of photogenerated holes. This structure efficiently accelerates the charge separation and electron transfer at the CoOx@CdS interface. Specifically, CoOx acts as a collector of holes promoting a more efficient photogenerated charge separation. This work presents a straightforward approach to construct the CoOx@CdS core-shell hererostructure as a robust photocatalyst for the transformation of solar energy.