An innovative Au-CdS/ZnS-RGO architecture for efficient photocatalytic hydrogen evolution

Abstract

An innovative CdS/ZnS-RGO hybrid is synthesizedviaan one-pot hydrothermal method. The further introduction of Au nanoparticles enables the composite with the merits of heterostructured semiconductor/semiconductor junction benefiting the hole transfer, as well as graphene and noble metal favorable for electron transportation.

The Evolution from a Typical Type-I CdS/ZnS to Type-II and Z-Scheme Hybrid Structure for Efficient and Stable Hydrogen Production under Visible Light

“…34 On the other hand, after coating ZnS, a new photoluminescence peak at ∼525 nm appears and its intensity evidently increases with the increase in ZnS coating amount. According to the previous reports, 32,35 the new photoluminescence peak at ∼525 nm is possibly caused by the excitation from defect energy levels introduced by rich Zn defects in the ZnS shell.…”

“…It can be inferred from the results of steady state and in situ SPV characterization that the photogenerated holes in CdS migrate to the ZnS shell under illumination so that photogenerated charge carriers in CdS can be effectively separated. This is due to the existence of Zn defects in ZnS, which introduce higher defect energy levels above the VB of ZnS . Since the defect energy levels introduced in ZnS are higher than the VB of CdS, the electrons in ZnS can be excited by two processes under AM 1.5 light irradiation, as shown in Scheme .…”

“…This is due to the existence of Zn defects in ZnS, which introduce higher defect energy levels above the VB of ZnS. 35 Since the defect energy levels introduced in ZnS are higher than the VB of CdS, the electrons in ZnS can be excited by two processes under AM 1.5 light irradiation, as shown in Scheme 1. Since the Fermi level of CdS is more negative than the introduced defect energy levels (V Zn and I S ), electrons on the CdS site at the CdS−ZnS interface will transfer and accumulate on the ZnS site so that it can form an interfacial electric field directed from CdS to ZnS.…”

Au Nanoparticle and CdS Quantum Dot Codecoration of In2O3 Nanosheets for Improved H2 Evolution Resulting from Efficient Light Harvesting and Charge Transfer

“…The distribution of elemental Au was also very uniform except for some observable surface aggregation. The aggregation can be ascribed to the concentrated photogenerated electrons accumulated on the In 2 O 3 surface, facilitating the formation and accumulation of Au NPs. , As a counterpart, the distribution of elements in In 2 O 3 /Au 4 was also studied, and the results are displayed in Figure S6. The distribution of elemental Au in In 2 O 3 /Au 4 is exactly the same as that in In 2 O 3 /Au 4 /CdS-12 (Figure S5).…”

Tailoring Morphology in Hydrothermally Synthesized CdS/ZnS Nanocomposites for Extraordinary Photocatalytic H2 Generation via Type-II Heterojunction

“…Several approaches, such as morphology control [5], crystal phase control [6], heterojunction formation [7,8], doping with metals [9] and nonmetals [10] have been employed to overcome these limitations. Nowadays, methods to improve the photocatalytic performance of CdS mainly focus on structural engineering or surface modification.…”