Enhanced electrochemical sensing performance for trace Hg(II) by high activity of Co3+ on Co3O4-NP/N-RGO surface

Recent advances in the modification of electrodes for trace metal analysis: a review

“…Nanocubes, nanoflakes, nanospheres, and nanodiamonds 75,[170][171][172][173][174][175] are among the other types of NMs used in the modification of the electrodes. Moreover, a poly(melamine)/grafitic-C 3 N 4 nanonetwork, 176 NiCo 2 O 4 nanocages, 177 Co 3 O 4 nanopolyhedrons, 88 and N,S-dual-doped carbon/sepiolite clay hybrid nanostructures 178 were also used in the modification of various types of electrodes.…”

“…NMs have been primarily applied on the electrodes in combination with other modifiers (including through the formation of composites). [22][23][24][25]27,[30][31][32]34,46,47,50,54,59,67,70,72,75,83,85,86,88,89,[92][93][94][95][96][97][98][99][100][101][102]107,113,115,117,118,[122][123][124][125][126][129][130][131]135,136,[138][139]...…”

“…In addition to the above-mentioned properties, carbon-based NMs are easy to apply, low cost, and abundant materials which can be further functionalized and serve as hosts for other compounds/ materials (mainly NPs). 191,192 These materials are mostly used either in combination with other modifiers, 24,30,34,47,54,56,57,59,64,67,70,75,85,86,88,107,113,115,129,147,149,160,162 or functionalized with other compounds. 146,148,158,159,167 In general, organic functionalization (i.e., oxygen and amino functionalization) and doping (mainly with nitrogen, boron, sulphur, and phosphorus) are the two main strategies used to improve the catalytic activity and increase active sites (affecting in this manner the electron-transfer process) and the hydrophilic nature of the carbon NMs.…”

“…Five main types of NMs, i.e. , graphene, graphene oxide (GO) and reduced graphene oxide (rGO), 22–92 NPs, 23–25,27,31,56,57,59,64,67,70,83,86,87,93–138 single and multiwalled carbon nanotubes (SWCNTs and MWCNTs), 32,83,89,98,99,101,113,129,133,139–162 nanosheets, 34,85,107,111,139,162–166 and nanofibers, 167–169 have been employed in the modification of the electrodes used in the determination of heavy metals. Nanocubes, nanoflakes, nanospheres, and nanodiamonds 75,170–175 are among the other types of NMs used in the modification of the electrodes.…”

“…NMs have been primarily applied on the electrodes in combination with other modifiers (including through the formation of composites). 22–25,27,30–32,34,46,47,50,54,59,67,70,72,75,83,85,86,88,89,92–102,107,113,115,117,118,122–126,129–131,135,136,138–156,160,162,168,175,179–189 However, in most of these studies, due to the lack of discussing the sensing mechanism of these nanocomposite-modified electrodes, there is no clear understanding of the influence of different components on the sensitivity and/or selectivity of the electrodes. Apart from the combination of different NMs (usually a combination of NPs and MWCNTs), 83,98,99,101,107,113,115,128,129,133,139,162 compounds and/or materials belonging to the other main groups of electrode modifiers have also been combined with NMs to modify the electrodes.…”