Enhanced Photocatalytic Hydrolysis Performance of Chiral Molecule Loaded Titanium Disulfide Nanosheets

Abstract

The photoelectrochemical (PEC) water decomposition is a promising method to produce hydrogen from water. To improve the water decomposition efficiency of the PEC process, it is necessary to inhibit the generation of H 2 O 2 byproducts and reduce the overpotential required by cheap catalysts and a high current density. Studies have shown that coating the electrode with chiral molecules or chiral films can increase the hydrogen production and reduce the generation of H 2 O 2 byproducts. This is interpreted as the result of a chiral induced spin selectivity (CISS) effect, which induces a spin correlation between the electrons that are transferred to the anode. Here, we report the adsorption of chiral molecules onto titanium disulfide nanosheets. Firstly, titanium disulfide nanosheets were synthesized via thermal injection and then dispersed through ultrasonic crushing. This strategy combines the CISS with the plasma effect caused by the narrow bandgap of two-dimensional sulfur compounds to promote the PEC water decomposition with a high current density.

Chiral Induced Spin Selectivity

“…In subsequent studies with helically aggregated dye molecules additional features of spin polarization on the characteristics of water splitting became apparent; not only was spin polarization responsible for decreasing the reaction overpotential for the OER, it was shown to inhibit the formation of hydrogen peroxide, as well as other super oxides . These effects have since been shown for other chiral catalysts, − including chiral metal oxides ,,,− and metal sulfides. , As an aside, we note that CISS may account, in part, for the high activity of photosystem II …”

“…406 These effects have since been shown for other chiral catalysts, 407−413 including chiral metal oxides 117,193,133,414−416 and metal sulfides. 183,184 As an aside, we note that CISS may account, in part, for the high activity of photosystem II. 417 Although chiral ligands improve OER efficiency, they can reduce the density of active sites on the catalyst surface.…”

“…Other methods for preparing chiral TiS 2 have also been demonstrated. 183 In related studies, Bian et al report spin-polarized electron currents as high as 75% through 5 μm thick films of MoS 2 184 and greater than 90% in >100 μm TiS 2 crystals. 185 The spin polarizations generated in chiral molecules and materials may also prove fruitful when interfaced with TMDs to break valley state degeneracy.…”

“…Interestingly, spin tunnel junction devices made from the materials show magnetoresistance exceeding 300%, over an order of magnitude larger than that observed in previous CISS-based systems. Other methods for preparing chiral TiS 2 have also been demonstrated . In related studies, Bian et al report spin-polarized electron currents as high as 75% through 5 μm thick films of MoS 2 and greater than 90% in >100 μm TiS 2 crystals …”