Graphene Quantum Dots Supported Mo₃S₄ as a Promising Candidate for Pt-Free Counter Electrode in Dye-Sensitized Solar Cell and Supercapacitor Applications

Abstract

We have synthesized with and without graphene quantum dots (GQDs) supported Molybdenum sulfide (Mo 3 S 4 /GQDs) by the hydrothermal route and examined the effect on electrochemical and dye sensitized solar cells (DSSCs) performance. The crystalline structure and composition are elucidated by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The synthesized samples show a spherical nature which is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). JV spectra reveal GQDs modified Mo 3 S 4 counter electrodes deliver the highest short circuit current (J SC ) of 13.84 mA cm −2 , open-circuit voltage (V OC ) of 0.72 V, and power conversion efficiency (PCE) of 5.67%, which is 13% higher compared to pristine counter electrodes. Low peak to peak separation (Epp) and higher peak current density (Jpc) and exchange current density (Jo) are responsible for this improvement. Besides, the samples have been employed as a working electrode and studied supercapacitor performance. Among them, Mo 3 S 4 /GQDs exhibited the highest specific capacitance of 234 F g −1 at 2 A g −1 . The results mentioned above reveal GQDs supported Mo 3 S 4 is not only a viable substitute for Pt-free counter electrodes but also provide a better outlook for energy storage devices.

Efficient Electron Transfer across Strontium Titanate Decorated Graphene Oxide for High‐Performance Dye‐Sensitized Solar Cells and Photocatalytic Degradation of Dye and Antibiotic

“…[28] The two-dimensional graphene nanosheet has unique characteristics such as high surface area, excellent carrier mobility, high optical transparency and excellent electrical conductivity, making it a spotlight material in photocatalytic activity and DSSC. [29][30][31][32] Graphene can generally be prepared from graphene oxide (GO) precursors by chemical reduction, with the resulting product known as reduced graphene oxide (rGO). Furthermore, the interface interaction between the semiconductor and graphene favours the electron transfer from the conduction band of the semiconductor to graphene.…”

Molybdenum Nitride and Oxide Quantum Dot @ Nitrogen-Doped Graphene Nanocomposite Material for Rechargeable Lithium Ion Batteries

“…The molybdenum nitrides are promising anode materials in LIBs among the various transition metal nitrides [1][2][3][4]. For the sake of overcoming the limitations of large volume change during the charge/discharge progress, low diffusion rate of electrolyte and lithium ion as well as poor electron transport at high rate of cycles, the molybdenum nitrides were prepared into all kinds of nano-shaped particles or/and combined with other materials forming composites [3,[5][6][7][8][9][10][11][12][13][14][15][16][17]. Zheng et al [18] prepared a nano-complex with Mo 2 N quantum dots @MoO 3 @nitrogen-doped carbon (MON-NC) by a sol-gel method.…”

East Asian Calligraphy Black Ink-Coated Paper as Flexible Conducting Electrode for Supercapacitor

“…16,[23][24][25][26][27][28] Supercapacitors usually use electric double layer capacitance (EDLC) and/or pseudocapacitance for energy storage. [29][30][31][32][33][34] Nowadays, commercially available supercapacitors afford advantages as fast charging and discharging; however, their energy density is still not comparable to that of conventional batteries. 16,24,35,36 In this light, pseoducapaciance and/or an ion intercalation process have been introduced to increase the energy density of supercapacitors.…”