Evaluation of thermally and chemically reduced graphene oxide films as counter electrodes on dye-sensitized solar cells (original) (raw)
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Moderately reduced graphene oxide as transparent counter electrodes for dye-sensitized solar cells
Electrochimica Acta, 2012
Moderately reduced graphene oxide (GO) films were fabricated by simple and fast thermal treatment of solution processed GO, and their application as an alternative to conventional Pt counter electrode in dye-sensitized solar cells (DSSCs) was investigated. GO without thermal treatment and thermally treated GO at 150 • C showed low efficiency of ∼0.5%, whereas cell performance was significantly improved by applying thermal treatment over 250 • C. In particular, the DSSC with GO thermally treated at 350 • C exhibited the highest performance with open-circuit voltage (V OC) of 0.66 V, short-circuit current density (J SC) of 16.35 mA/cm 2 , F.F. of 33.33%, and overall power conversion efficiency (PCE) of 3.60%. Moderate reduction of GO by simple thermal treatment over 250 • C was confirmed through the measurements of X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Enhancement of efficiency after high temperature thermal treatment might be attributed to the improved electrical conductivities and higher catalytic activities, resulting from the reduction of GO.
ChemEngineering
Reduced graphene oxide has certain unique qualities that make them versatile for a myriad of applications. Unlike graphene oxide, reduced graphene oxide is a conductive material and well suited for use in electrically conductive materials, such as solar cell devices. In this study, we report on the synthesis of graphene oxide as well as the fabrication and characterization of dye-sensitized solar cells with a photoanode which is an amalgam of reduced graphene oxide and titanium dioxide. The synthesized reduced graphene oxide and the corresponding photoanode were fully characterized using Ultraviolet-visible, Fourier transform infrared (FTIR), and Raman Spectrometry. The morphology of the sample was assessed using Atomic Force Microscopy, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy, and Energy Dispersive X-ray Spectroscopy. The photovoltaic characteristics were determined by photocurrent and photo-voltage measurements of the fabricated solar cells. T...
Dye-sensitized solar cells (DSSCs) are one type of highly efficient low-cost solar cells among third-generation photovoltaic devices. Replacing the expensive components of DSSCs with alternative inexpensive and earth-abundant materials would further reduce their price in the solar cell market. Recently, graphene-based low-cost counter electrodes (CEs) have been developed, which could serve as a potential alternative to the expensive platinum-based CEs. In this review article, we have summarized recent research on various reduced graphene oxide (rGO)-based composite CE materials, methods for their synthesis, their catalytic activity, and the effective utilization of such CEs in DSSCs. The photovoltaic performance of DSSCs made of rGO-based composite CEs were compared with the reference Pt-based cells, and the photovoltaic parameters are summarized in tables.
Utilizing reduced graphene oxide for achieving better efficient dye sensitized solar cells
Journal of Alloys and Compounds, 2019
In the last couple of years the use of carbon allotropes in energy generating and energy storage devices has increased owing to their exceptional properties. In applications where charge transfer is required, reduced graphene oxide (rGO) is the preferred choice. The current work reports the synthesis of rGO by microwave and electrochemical method. Further the rGO have been used in the working electrode of DSSC in various configurations. Using quasi-solid polymer electrolyte we obtained a short circuit current density (J sc) of 2.15 mA/cm 2 , open circuit voltage (V oc) of 0.54 V and an efficiency (h) of 0.58%. Because of the presence of polymer electrolyte the cell parameters improved after a period of 72 h and the same have been presented with their electrochemical impedance studies.
Pt-free spray coated reduced graphene oxide counter electrodes for dye sensitized solar cells
Solar Energy, 2016
Graphene oxide (GO) was synthesized using a modified Hummers method and was reduced by using focused sunlight to obtain solar reduced graphene oxide (SRGO). GO and SRGO are then used as Ptfree counter electrode materials in dye sensitized solar cells (DSSCs). GO and SRGO counter electrodes were prepared by a simple spray coating method to produce homogeneous electrode layers. The DSSCs with GO and SRGO counter electrodes exhibited an overall power conversion efficiencies of 3.4and3.4 and 3.4and4%, respectively. Cyclic voltammetry and electrochemical impedance spectroscopy reveal that the DSSC with SRGO counter electrode exhibits higher electro-catalytic activity and lower charge transfer resistance at the electrode/electrolyte interface (in comparison to the DSSC with GO) resulting in higher conversion efficiency. Moreover, the microstructural features of SRGO are found to be suitable for its improved interaction with the liquid electrolyte and the enhanced electro-catalytic activity at its surface.
Evaluation of solution processable polymer reduced graphene oxide transparent films as counter electrodes for dye-sensitized solar cells, 2020
This paper reports the synthesis of reduced oxide (RGO) coated polyaniline (PANi) nanocomposites via in-situ emulsion polymerization and its application as counter electrode for dye sensitized solar cells (DSSCs). The synthesized nanocomposites were systematically characterized through Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform resonance infra-red (FTIR) and Raman spectroscopy indicating the uniform intercalation of polyaniline with reduced graphene oxide. The synergy between RGO and PANi chains owing to the co-doped SDS and H 2 SO 4 leads to the enhanced solubility and improved electrocatalytic activity, that was further confirmed through electrochemical measurements to satisfy the criteria for application as cost effective counter electrode material for scalable DSSC. The fabricated CE was highly transparent and reached the conversion efficiency which is comparable to that of Platinum with a current density of (12.58 mAÁcm À2) and (13.11 mAÁcm À2) respectively under an illumination of AM 1.5 G (100 mWÁcm À2) simulated solar light with an overall photo conversion efficiency of 3.9%. Thus PANi/RGO based nanocomposites could therefore serve as efficient alternative material to Pt. free CE in DSSC.
Malaysian Journal of Analytical Science, 2017
Platinum (Pt) is a conventional material for counter electrodes of dye-sensitized solar cells (DSSCs) due to its excellent electrocatalytic activity in the redox process. However, the high cost of Pt motivates researchers to search for composite materials of Pt to reduce its consumption. This study is aimed to reduce Pt usage by incorporating reduced graphene oxide (rGO) with Pt of different ratios in counter electrode thin films and to determine the optimum ratio with the highest efficiency. A DSSCbased platinum/rGO (Pt/rGO) counter electrode composite was fabricated using doctor-blade method. X-ray diffraction analysis was performed to examine the crystallite structure of the Pt/rGO thin film. The optimum ratio was found to be 70:30 of Pt:rGO, with current-voltage characterization showing an efficiency of 5.5%, open-circuit voltage of 0.739 V, current density of 12.5 mA/cm 2 , and fill factor of 59.24%.
Nanoscale, 2014
NiO nanoparticles (NPs) were hybridized on the surface of reduced graphene oxide (RGO) by dry plasma reduction (DPR) at atmospheric pressure without any toxic chemicals and at a low temperature. NiO-NPs of 0.5-3 nm size, with a typical size of 1.5 nm, were uniformly hybridized on the surface of RGO. An XPS analysis and the Raman spectra also revealed the repair of some structural damage on the basal plane of the graphene. The material when applied to the counter electrode (CE) of dye-sensitized solar cells (DSCs) exhibited a power conversion efficiency of 7.42% (AE0.10%), which is comparable to a conventional Pt-sputtered CE (8.18% (AE0.08%)). This material outperformed CEs produced using NiO-NPs (1.53% (AE0.15%)), GO (4.48% (AE0.12%)) and RGO (5.18% (AE0.11)) due to its high electrochemical catalytic activity and high conductivity. The charge transfer resistance for NiO-NP-RGO was as low as 1.93 U cm 2 , while those of a NiO-NP-immobilized electrode and a GO-coated electrode were 44.39 U cm 2 and 12.19 U cm 2 , respectively, due to a synergistic effect.
Reduced Graphene Oxide Decorated TiO2 for Improving Dye-Sensitized Solar Cells (DSSCs)
Current Nanoscience, 2019
In this comprehensive study, the influence of titanium dioxide (TiO2) dopants decorated on Reduced Graphene Oxide (rGO) via spin coating technique as an efficient photoelectrode in DSSCs was investigated in detail. This study aims to determine the optimum spinning duration for decorating TiO2 onto rGO nanosheet photoanode for high DSSCs performance. The rGO nanosheet was prepared using the electrodeposition method. A dropped of 0.2 wt% of TiO2 solution was absorbed using micro-pipette (0.1 μl) and continuously applied on FTOrGO surface with the rate of 0.1 μl/5s. The spinning duration was varied from 10 to 50 s, and resultant samples were labelled as Lt, where t= 10, 20, 30, 40 and 50s, respectively. The experimental results showed that TiO2 decorated rGO nanosheet photoanode for 30s spinning duration exhibited a maximum power conversion efficiency of 9.98% than that of pure rGO nanosheet photoanode (4.74%) under 150 W of xenon irradiation, which is about 2.1 times improvement in DSSCs performance. Ti4+ ion was decorated onto rGO nanosheet leading to the highest interactions with the O-H functional group or Ti4+ could react with the epoxide or phenolic groups in rGO forming the Ti-O-C bonds.
ACS Applied Electronic Materials, 2020
The introduction of an efficient and precious platinum (Pt) free counter electrode (CE) for dye-sensitized solar cells (DSSCs) is an important aspect to address. In this report, we have employed nanoporous reduced graphene oxide (PG) containing PEDOT:PSS−PG composite on FTO substrate as CEs, which have shown excellent diffusion of I 3 − , remarkable photocatalytic activity, and better device performance along with desired stability. The investigated cathode material has been prepared by mixing PGs and highly conducting PEDOT:PSS. Experimental measurements and analyses such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and so on indicate that PEDOT:PSS−PG is a promising cathode material for a Pt-free CE in DSSCs. EIS indicates that the PEDOT:PSS−PGs have lower interfacial charge-transfer resistance because of their high electrical conductivity and superior electrocatalytic activity. The achieved photoconversion efficiency (η) of a DSSC employing the Pt-free PEDOT:PSS−PG/FTO CE is 9.57%, which is found to be comparable to that of Pt/FTO CE based DSSC (9.64%) under a simulated solar light illumination of 100 mW/ cm 2 .