A general review on the thiospinels and their energy applications

Antil

ACS Appl. Mater. Interfaces

et al. 2022

Transition metal phosphides (TMPs) are expected to be excellent electrocatalysts for oxygen evolution reaction (OER) because of their high stability, highly conducting metalloid nature, highly abundant constituting elements, and the ability to act as a precatalyst due to in situ surface-formed oxy-hydroxide species. Herein, a "one-pot" colloidal approach has been used to develop a rod-shaped one-dimensional non-noble metal FeCoP electrocatalyst, which exhibits an excellent OER activity with an exceptionally high current density of 950 mA cm −2 , a turnover frequency value of 7.43 s −1 , and a low Tafel slope value of 54 mV dec −1 . The FeCoP electrocatalyst affords OER ultralow overpotentials of 230 and 260 mV at current densities of 50 and 100 mA cm −2 , respectively, in 1.0 M KOH, and demonstrates a superior catalytic stability of 10,000 cycles and durability up to 60 h at 50 mA cm −2 . An insight into the superior and stable electrocatalytic OER performance by the FeCoP nanorods is obtained by extensive Xray photoelectron spectroscopy, X-ray diffraction, Raman and infrared spectroscopy, and cyclic voltammetry analyses for a mechanistic study. This reveals that a high number of electrocatalytically active sites enhance the oxygen evolution and kinetics by offering metal ion sites for utilitarian in situ surface formation and adsorption of *O, *OH, and *OOH reactive species for OER catalysis.

Section: Resultscontrasting

confidence: 53%

A Superior and Stable Electrocatalytic Oxygen Evolution Reaction by One-Dimensional FeCoP Colloidal Nanostructures

Antil

ACS Appl. Mater. Interfaces

et al. 2022

“…The [Cr2-xSnx]X6 octahedron showed a ~2.0% degree of distortion, which agrees with the octahedral distortions in chalcospinels already reported in our previous research [5,6,13]. The single positional u parameter of the chalcogen atoms (u, u, u), Wyckoff position 32e, of CuCr1.1Sn0.9S2.3Se1.7, was 0.25484 (4), which is comparable to the values found in cubic CuCr1.7Sn0.3Se4 and CuCr1.5Sn0.5Se4: u = 0.25663(4) and u = 0.25632(3), respectively [6].…”

Section: Crystal Structure Analysis Pxrd Patterns and Sem-eds Analysessupporting

confidence: 90%

“…This has been the focus of many studies because of its potential for use in new data storage devices with reduced energy consumption [2,3]. Therefore, solid solutions of seleno-and thiospinels have been well studied because of their extraordinary electrical and magnetic properties, which can differ significantly by substitution [4][5][6][7][8][9][10][11]. For example, replacing metal ions in the octahedral or tetrahedral position with diamagnetic ions can alter the magnetic properties of CuCr2S4 and CuCr2Se4.…”

Section: Introductionmentioning

confidence: 99%

Effects of Tin and Sulfur Chemical Substitution on the Structural and Electrical Properties of CuCr2Se4 Selenospinel

et al. 2022

A series of CuCr2-xSnxS2.3Se1.7 and CuCr2-xSnxS1.7Se2.3 (x = 0.4, 0.6, and 1.0) compounds were prepared by solid-state reaction at a high temperature. Single-crystal X-ray diffraction analysis showed that CuCr1.1Sn0.9S2.3Se1.7 crystallizes in a spinel-type structure (cubic Fdm space group). The others samples were also consistent with a spinel-type structure but through powder X-ray diffraction patterns and Rietveld refinements. The systems studies showed p-type semiconductor behavior with a carrier concentration per volume of approximately ~+1020 cm−3. The electrical conductivity, σ, showed tin-content dependence. The conductivity of CuCr2‑xSnxS1.7Se2.3 increased from ~9.0 to ~17.0 S·cm−1 at room temperature (RT) for x = 0.4 and 0.6, respectively, and the magneto-resistance average value determined for CuCr2-xSnxS2.3Se1.7 and CuCr2-xSnxS1.7Se2.3 was approximately ~10−4 Ω (0.566 T, external magnetic field). DFT calculations revealed that the Cr centers concentrated most of the spin density. A smaller spin polarization featuring the opposite spin was observed for S/Se atoms.

“…[28] However, introducing vacancies in sulfide would also result in the disorder of crystal structure, which would show a negative effect on rate performance and cyclic stability. [29] Moreover, when using NaBH 4 and hydrazine as reductant, the gas evolution is opposite to the permeation direction of reductant solution, depressing the reduction reaction inside the electrode as well as the formation of sulfur vacancies. Thus far, few work on introducing sulfur vacancies to enhance the performance of sulfide electrodes with high massloading had been reported.…”

Section: Introductionmentioning

confidence: 99%

CoNi₂S₄ Electrode with High Mass‐Loading for High‐Energy‐Density Supercapacitor: Role of S‐Containing Anions Exchange

Wang

Chen

et al. 2023

Chemistry A European J

Anion exchange is recognized as an effective method to regulate the composition, electronic conductivity, and electrochemical behavior of the transition metal-based compounds. In this work, anion exchange is adopted as a rational post-treatment route to facilitate the capacitive activity of CoNi 2 S 4 nanoparticle arrays grown on carbon cloth (CC) with high mass-loading. As soaked in saturated Na 2 S solution, the CoNi 2 S 4 /CC electrode showed an increased capacity from 483 C g À 1 to 841 C g À 1 at 10 mA cm À 2 with excellent rate performance and stable cycling performance, which was superior to the CoNi 2 S 4 /CC electrode activated by NaBH 4 reduction. Anion exchange was beneficial for enhancing the crystallinity, retaining the adhesion of nanoarrays, and realizing low resistance nature in a mild route. The asassembled CoNi 2 S 4 /CC//activated CC hybrid supercapacitor delivered a high areal capacitance of 1.28 F cm À 2 at 5 mA cm À 2 , and achieved an energy density of 0.58 mWh cm À 2 at a power density of 4.5 mW cm À 2 with excellent cycle stability with 90.6 % capacity retention after 10000 cycles.