Synthesis, characterization and electrocatalytic properties of two new open Wells-Dawson-type tungstosilicates

Abstract

Two new open Wells-Dawson-type polyoxometalates (POMs), K₇H₂[K(Co(H₂O)₄)₂Co(H₂O)₂(Si₂W₁₈O₆₆)]·22H₂O and K₇H₂[{C(NH₂)₃} (Co(H₂O)₄)₂Co(H₂O)₂(Si₂W₁₈O₆₆)]·20H₂O (abbreviated as K-Co₃Si₂W₁₈ and C(NH₂)₃-Co₃Si₂W₁₈), were synthesized by conventional synthesis and characterized by X-ray single crystal and powder diffraction (XRSCD and XRPD), IR and UV-vis absorption spectra. XRSCD analysis reveals that two tungstosilicates have similar anionic structures with an open Wells-Dawson anion [Si₂W₁₈O₆₆]¹⁶⁻ and three Co²⁺ ions. The electrocatalytic activities of both compounds toward the reduction of H₂O₂ and NaNO₂ were studied. Also their electrocatalytic water oxidation performance was evaluated at neutral pH.

Graphical Abstract

Keywords:

• Tungstosilicates
• open Wells-Dawson structure
• crystal structure
• electrocatalytic reduction
• electrocatalytic water oxidation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China (no. 21671091), the Natural Science Foundation of Liaoning Province (no. 20180550544), the Opening Project of Key Laboratory of Polyoxometalate Science of Ministry of Education, and the Scientific Research Project of Liaoning Normal University (GD19L005).