Intercalation makes the difference with TiS₂: Boosting electrocatalytic water oxidation activity through Co intercalation

Abstract

Intercalated and unmodified TiS 2 nanomaterials were synthesized and characterized by UV-Visible-NIR spectroscopy, Powder X-Ray Diffraction, and X-Ray Photoelectron and Ultraviolet Photoelectron Spectroscopy. Photoelectron spectroscopy measurements indicated that CoS and Cu 2 S appeared to be intercalated between sheets of partially or fully oxidized TiS 2 , which could be solution processed on conductive oxide substrates. The materials were then applied toward water oxidation and evaluated by cyclic voltammetry, chronoamperometry, and impedance measurements. While unmodified TiS 2 was not observed to perform well as an electrocatalyst with overpotentials .3 V in 1 M NaOH electrolyte, CoS intercalation was found to lower the overpotential by ;1.8-1.44 V at 10 mA/cm 2 . Conversely, Cu 2 S intercalation resulted in only a modest increase in performance (.2.3 V overpotential). Impedance measurements indicated that intercalation increased the series resistance in the as-prepared samples but decreased the series resistance in oxidized samples.

Enhanced Pseudo-Capacitive Contributions to High-Performance Sodium Storage in TiO2/C Nanofibers via Double Effects of Sulfur Modification

“…1 d), the chemical state of sulfur was characterized by several peaks. The low-energy ones at 161.2 and 162.4 eV can be attributed to the TiS 2 phase [ 30 , 31 ]. The high-energy doublet centered at 163.9 and 165.1 eV can be correlated with S-Ti and S-C, which confirm S doping of TiO 2 bulk and of carbon fibers [ 32 ].…”

Electrochemical Properties and Reaction Mechanism of NiTi2S4 Ternary Metal Sulfide as an Anode for Lithium Ion Battery

“…The peaks at 456.6 and 462.1 eV were well matched with Ti 3+ . Similar to Ni, the peak couples of 454.8 and 460.5 eV and 458.7 and 464.4 eV can be assigned to the surface oxidized Ti (TiO and TiO 2 ). − The S 2p spectrum was deconvoluted into two peaks centered at 161.3 and 162.4 eV, which were assigned to S 2p 3/2 and S 2p 1/2 of divalent sulfide ions (S 2– ), respectively (Figure d) …”