Facet-dependent electrochemical properties of Co3O4 nanocrystals toward heavy metal ions

Abstract

We revealed an interesting facet-dependent electrochemical behavior toward heavy metal ions (HMIs) based on their adsorption behaviors. The (111) facet of Co3O4 nanoplates has better electrochemical sensing performance than that of the (001) facet of Co3O4 nanocubes. Adsorption measurements and density-functional theory (DFT) calculations reveals that adsorption of HMIs is responsible for the difference of electrochemical properties. Our combined experimental and theoretical studies provide a solid hint to explain the mechanism of electrochemical detection of HMIs using nanoscale metal oxides. Furthermore, this study not only suggests a promising new strategy for designing high performance electrochemical sensing interface through the selective synthesis of nanoscale materials exposed with different well-defined facets, but also provides a deep understanding for a more sensitive and selective electroanalysis at nanomaterials modified electrodes.

The Effect of Crystal Face of Fe2O3 on the Electrochemical Performance for Lithium-ion Batteries

“…In contrast, the packing densities of the (010) facets for ions are 2.89 nm −2 and 5.78 nm −2 . Due to the high atomic density, more Fe 3+ ions participate in the reaction, and lead to a high specific capacity28. The detailed crystal structure of Fe 2 O 3 have been displayed in Fig.…”

“…To prepare FeOOH nanorods precursors, 1.9 mmol of FeCl 3 ·6H 2 O was put into 15 ml of deionized water to form a homogeneous solution, then added 15 ml of 0.8 M NaOH solution under stirring, quickly. After stirring for 10 min, the total solution was transferred into a 50 ml Teflon-lined stainless steel autoclave, sealed and heated at 180 °C for 4 h. The result product was collected by centrifugation, washed with deionized water and ethanol, then was dried at 80 °C and calcined at 250 °C for 2 h. The Fe 2 O 3 nanosheets were synthesized based on the previous work28. 5.1 mmol of FeCl 3 ·6H 2 O was dissolved in 35 ml of anhydrous ethanol, and 38.4 mmol of CH 3 COONa·3H 2 O was rapidly added into the solution with stirring.…”

“…Huang et al . found the facet-dependent electrochemical properties of Co 3 O 4 toward heavy metal ions and found that the Co 3 O 4 nanoplates with (111) facet performed better electrochemical sensing capability than the Co 3 O 4 nanocubes with (001) facet28. Not long ago, we also reported the facet-dependent electrochemical capability of Co 3 O 4 as anode material for Li-ion batteries and proved the Co 3 O 4 octahedron with exposed (111) plane exhibited more excellent electrochemical properties than that of Co 3 O 4 cube with exposed (001) plane and Co 3 O 4 truncated octahedron with exposed (001) and (111) planes29.…”

An electrochemical sensor based on Co3O4 nanosheets for lead ions determination

“…14 Due to the electrochemical stability and adsorption capacity, Co 3 O 4 nanocrystals synthesized via a hydrothermal process were used for the detection of Pb(II). 15 However, the synthetic method of Co 3 O 4 suffered from the complications of the complex synthesis process and needed organic additives. Therefore, it is necessary to develop a mild and easily controlled method for preparing Co 3 O 4 nanostructures for metal ions detection.…”

Enhanced Electroactivity of Facet-Controlled Co3O4 Nanocrystals for Enzymeless Biosensing

“…In particular, the facet-dependent property is among the most exciting aspect of the research because the activity of an inactive material may be remarkably enhanced by revealing highly active facets without changing the composition [1,3] . For instance, spinel cobalt oxide (Co 3 O 4 ) has shown superb performance in catalysis [4,5] and heavy metal ion sensing [6] , with selectively exposed crystal facets. Such results are ascribed to the surface configuration and the density of active species at the crystal facets [1] .…”