Perfect inhibition of CdS photocorrosion by graphene sheltering engineering on TiO₂ nanotube array for highly stable photocatalytic activity

Abstract

An artful graphene sheltering engineering onto TiO2 nanotube array for perfect inhibition of CdS photocorrosion (RGO/CdS-TiO2 NT) has been developed by a one-step electrodeposition method. The CdS photocorrosion driven by both holes and radicals has been systematically investigated and identified. The RGO layer provides a perfect protection to CdS through (i) blocking the attack of active species especially ˙OH radicals and (ii) offering a closed electron-rich microenvironment where the stored electrons RGO(e(-)) not only reduce intermediate species S˙(-) to S(2-) but also compensate the valence band of CdS for its loss of electrons to alleviate CdS photocorrosion from oxidation by holes. The photocatalyst exhibits extremely high stability. RGO/CdS-TiO2 NT shows high visible-light photocatalytic activity for the degradations of organic dye methylene blue (MB), industrial chemical p-nitrophenol (PNP) and herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). This work provides a new insight into the protection of photosensitive semiconductors from photocorrosion.

Improving the contact properties of CdS-decorated TiO2 nanotube arrays using an electrochemical/thermal/chemical approach

“…In that regard, CdS-decorated TNAs have been investigated in quantum dot (QD)-sensitized solar cells [1,[5][6][7], photoelectrochemical hydrogen production [8], and photocatalytic and photoelectrocatalytic degradation of contaminants in water [9][10][11]. Different methods have been reported to couple CdS with TNAs, among which the successive ionic layer adsorption and reaction (SILAR) process and the electrochemical deposition of CdS precursors [11][12][13][14] are the most commonly used. Both methods involve reactions between solvated Cd 2+ and S 2− ions located near the TNA surface, which does not ensure strong bonding between CdS and TNAs [15], thus leading to poor contact properties that affect the adhesion and the charge transport at the CdS/TNA interface.…”

Stabilizing and Improving Solar H2 Generation from Zn0.5Cd0.5S Nanorods@MoS2/RGO Hybrids via Dual Charge Transfer Pathway

“…39 In addition, XPS signals of Mo 3d in Figure 2d are observed at binding energies around 229.4 eV and 232.4 eV in the typical ZCS@MoS 2 /RGO which ascribed to doublet Mo3d 5/2 and Mo3d 3/2 , which are consistent with the data of MoS 2 . 40 Compared to the ZCS nanorods, the typical ZCS@MoS 2 /RGO shows both binding energy of Zn 2p and Cd 3d towards high value, which can be a strong evidence for presence of interactions between ZCS and RGOsheets 40,41. To confirm the deoxygenation of GO using the photo-assisted reduction method, XPS spectrum of C1s of ZCS@MoS 2 /RGO is compared with that of initial GO.…”

Palladium-decorated zinc sulfide/reduced graphene oxide nanocomposites for enhanced visible light-driven photodegradation of indigo carmine

“…However, reduced graphene oxide has been reported to stabilized metal sulfides and inhibit their corrosion [38]. The addtion of reduced graphen oxides to ZnS is therefore anticipated to siginificanlty reduced the photocorrosive properties of ZnS and improve its photocatlyic performance.…”