*Article* **Reactive Insertion of PEDOT-PSS in SWCNT@Silica Composites and its Electrochemical Performance**

### **Halima Djelad 1,2, Abdelghani Benyoucef 1, Emilia Morallón 2 and Francisco Montilla 2,\***


Received: 30 January 2020; Accepted: 3 March 2020; Published: 6 March 2020

**Abstract:** Hybrid silica-modified materials were synthesized on glassy carbon (GC) electrodes by electroassisted deposition of sol-gel precursors. Single-wall carbon nanotubes (SWCNTs) were dispersed in a silica matrix (SWCNT@SiO2) to enhance the electrochemical performance of an inorganic matrix. The electrochemical behavior of the composite electrodes was tested against the ferrocene redox probe. The SWCNT@SiO2 presents an improvement in the electrochemical performance towards ferrocene. The heterogeneous rate constant of the SWCNT@SiO2 can be enhanced by the insertion of poly(3,4-Ethylendioxythiophene)-poly(sodium 4-styrenesulfonate) PEDOT-PSS within the silica matrix, and this composite was synthesized successfully by reactive electrochemical polymerization of the precursor EDOT in aqueous solution. The SWCNT@SiO2-PEDOT-PSS composite electrodes showed a heterogeneous rate constant more than three times higher than the electrode without conducting polymer. Similarly, the electroactive area was also enhanced to more than twice the area of SWCNT@SiO2-modified electrodes. The morphology of the sample films was analyzed by scanning electron microscopy (SEM).

**Keywords:** PEDOT-PSS; SiO2; sol-gel; hybrid materials; ferrocene
