Pt-free, low-cost and efficient counter electrode with carbon wrapped VO2(M) nanofiber for dye-sensitized solar cells

Abstract

The present study reports the use of one-dimensional carbon wrapped VO2(M) nanofiber (VO2(M)/C) as a cost-effective counter electrode for dye-sensitized solar cells (DSSCs); where M denotes monoclinic crystal system. Uniform short length nanofiber was synthesised by a sol-gel based simple and versatile electrospinning and post carbonization technique. The investigation of nanostructure and morphological analysis were performed by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and transmission electron microscope (TEM) with EDAX. The electrochemical response was comprehensively characterized by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization. The electrochemical analysis of the VO2(M)/C nanofiber counter electrode exhibits significant electrocatalytic activity towards the reduction of triiodide and low charge transfer resistance at the electrode-electrolyte interface. The DSSCs fabricated with carbon-wrapped VO2(M) nanofiber CE showed high power conversion efficiency of 6.53% under standard test condition of simulated 1SUN illumination at AM1.5 G, which was comparable to the 7.39% observed for conventional thermally decomposed Pt CE based DSSC under same test conditions. This result encourages the next step of modification and use of low-cost VO2(M) as an alternate counter electrode for DSSCs to achieve a substantial efficiency for future energy demand.

Repositioning N-Acetylcysteine (NAC): NAC-Loaded Electrospun Drug Delivery Scaffolding for Potential Neural Tissue Engineering Application

“…The isotherm is not closed, which may be due to the swelling phenomenon due to the formation of very narrow slip pores or bottle-shaped pores present over the microporous structure. Nitrogen adsorption below the relative pressure of P/Po < 1 was indicative of the formation of micropores [ 50 ]. The nanofibers have a pore size distribution covering both the micro and mesoporous ranges.…”

The Synchronization of Electron Enricher and Electron Extractor as Ternary Composite Photoanode for Enhancement of DSSC Performance

“…When dye molecule absorbs the light, the e − is excited (1) and transferred to the CB of P25 (2). The e − at this state can move to CB of N-, S-TiO 2{001} -2F (3) via e − hopping mechanism, and it can be further extracted by N-, S-rGO-(PreEx-LT), which acts as e − extractor, through the external circuit performing work (4). Moreover, the N-, S-TiO 2{001} -2F as the e − enricher can be easily excited by visible light (5) (pink arrow in the first circle), resulting in high density of photoexcited e − .…”

“…Dye-sensitized solar cell (DSSC) has gained a considerable attention as a potential solar device. The performance of the DSSC could be improved by several strategies, including the development of more efficient dye sensitizers [1,2] electrolyte systems [3], counter electrodes [4,5], and photoanodes [6,7]. Among these, the photoanode is an integral part determining the overall efficiency of DSSC because it has strong influence on dye adsorption ability and charge transport properties [8,9].…”

Progress of MOF Derived Functional Materials toward Industrialization in Solar Cells and Metal-Air Batteries

“…Due to its high cost, researchers have been utilizing alternative materials with low cost, good stability, and high catalytic characteristics. [34][35] [36] Nowadays, MOFs were intensively studied for their appealing physicochemical properties which render them interesting materials for CE. [37][38] [39] However, their employment as CE is quite limited due to the inherent mild conductivity, and the development of composite materials, including MOFs as well as conductive polymers, is typically needed to achieve the transport of charge in such application.…”