WS2 as an Effective Noble-Metal Free Cocatalyst Modified TiSi2 for Enhanced Photocatalytic Hydrogen Evolution under Visible Light Irradiation

Abstract

Abstract:A noble-metal free photocatalyst consisting of WS 2 and TiSi 2 being used for hydrogen evolution under visible light irradiation, has been successfully prepared by in-situ formation of WS 2 on the surface of TiSi 2 in a thermal reaction. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results demonstrate that WS 2 moiety has been successfully deposited on the surface of TiSi 2 and some kind of chemical bonds, such as Ti-S-W and Si-S-W, might have formed on the interface of the TiSi 2 and WS 2 components. Optical and photoelectrochemical investigations reveal that WS 2 /TiSi 2 composite possesses lower hydrogen evolution potential and enhanced photogenerated charge separation and transfer efficiency. Under 6 h of visible light (λ > 420 nm) irradiation, the total amount of hydrogen evolved from the optimal WS 2 /TiSi 2 catalyst is 596.4 µmol·g −1 , which is around 1.5 times higher than that of pure TiSi 2 under the same reaction conditions. This study shows a paradigm of developing the effective, scalable and inexpensive system for photocatalytic hydrogen generation.

Facile Sonication Synthesis of WS2 Quantum Dots for Photoelectrochemical Performance

“…PEC activity was measured using a standard three-electrode electrochemical configuration combined with Xe illuminant (Figure 5a) in 0.5 M sodium sulfate (Na 2 SO 4 ) solution with a scan rate of 10 mV/s [5,29]. As shown in Figure 5b, when the applied voltage was slowly increased from 0.2 V to −0.5 V, the empty ITO (Indium tin oxide) curve (green) was almost a straight line.…”

“…Since the discovery of graphene, 2D materials, such as tungsten disulfide (WS 2 ) and other transition metal dichalcogenides (TMDCs), have drawn a great deal of interest due to their attractive physical and electronic properties [1][2][3]. It is reported that the hydrogen binding energy of MoS 2 is close to that of Pt-group metals, thus hinting at potential applications of other TMDCs in photocatalytic HER [4][5][6][7][8][9]. Both computational and experimental results have confirmed that the photocatalytic activities of XS 2 (X could be other transition metals, such as W) mainly stem from the edges rather than the basal planes [10,11].…”

Preparation of Rh/Ni Bimetallic Nanoparticles and Their Catalytic Activities for Hydrogen Generation from Hydrolysis of KBH4

“…However, the technique for hydrogen storage is still a large problem which hinders the application of hydrogen. To date, an extensive body of research has been published on hydrogen storage including liquid hydrogen storage, high pressure gaseous hydrogen storage, adsorption hydrogen storage, metal hydride hydrogen storage, organic compounds hydrogen storage, and liquid phase chemical hydrogen storage [1][2][3][4]. Among these methods, liquid phase chemical hydrogen storage attracted considerable attention due to their high hydrogen content, high hydrogen purity, and easy control of the hydrogen generation rate [5,6].…”

One-Step Synthesis of MoS2/TiSi2 via an In Situ Photo-Assisted Reduction Method for Enhanced Photocatalytic H2 Evolution under Simulated Sunlight Illumination

“…In recent decades, semiconductor photocatalysis has received close attention owing to its potential application in the production of renewable hydrogen [1,2]. Since the discovery of photoelectrocatalytic H 2 production in the TiO 2 electrode by Fujishima and Honda in 1972 [3], the semiconductor photocatalyst (Eg ≈ 3.2 eV) has been investigated extensively [4,5].…”

“…After that, a series of TiSi 2 -based compounds or composites, including TiSi 2 -SiC [11], Ti 5 Si 3 [12], TiO 2 /TiSi 2 [7,8], were synthesized. RuO 2 /TiSi 2 /RGO hybrid and WS 2 /TiSi 2 composite were also successfully synthesized by our group [1,13]. These novel materials showed improved photoelectrochemical properties and enhanced photocatalytic activity.…”