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Co(OH)2/BiVO4 photoanode in tandem with a carbon-based perovskite solar cell for solar-driven overall water splitting
摘要： BiVO4 as a promising candidate photoanode material for PEC water splitting has been paid much attention due to its low cost, nontoxicity, high stability and narrow band gap energy of 2.4 eV. However, owing to its short carrier diffusion length and poor charge separation consequence the achieved efficiency of the BiVO4 photoanode is still limited. Herein, we addressed this issue by loading Co(OH)2 onto as-prepared BiVO4 to fabricate Co(OH)2/BiVO4 heterojunction photoanode via a simple solution impregnation method, in which Co(OH)2 as a modifier can increase interface charge separation efficiency from 44% of BiVO4 to 92% of Co(OH)2/BiVO4. As a result, the water-splitting photocurrent density was significantly enhanced from 1.57 mA/cm2 of BiVO4 to 4.52 mA/cm2 of Co(OH)2/BiVO4 at 1.23 V vs. RHE under 1-sun illumination. Further, the Co(OH)2/BiVO4 photoanode was assembled in tandem with a single sealed carbon-based PSC, and the resulting PV-PEC device showed a high STH efficiency of 4.6% and decent stability. The produced H2 and O2 gases were determined as ~68 μmol/cm2/h and ~34 μmol/cm2/h, respectively, corresponding to the 2:1 ratio of water splitting reaction with a faradaic efficiency of ~98%.
关键词： heterojunction photoanode,water splitting,tandem device,Co(OH)2/BiVO4
更新于2025-09-12 10:27:22
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Cobalt complex dye as a novel sensitizer in dye sensitized solar cells
摘要： In this study, cobalt metal complex has been introduced as a novel class of sensitizer for more mechanistic consideration of the photovoltaic conversion efficiency (PCE) of dye sensitized solar cells. UV-Vis spectroscopy of dye illustrates maximum absorption at wavelengths of dye in 498 and 650 nm. TiO2 was used as the photoanode of the cell whose X-ray diffraction spectrum indicates that its crystal phase is anatase (101). Surface morphology of photoanode was also investigated by scanning electron microscopy (SEM) and obviously showed ~25nm TiO2 nanoparticles. The cyclic voltammetry (CV) investigation of Pt-coated fluorine doped tin oxide (FTO) as the counter electrode of the cell indicates redox process on this electrode. Photovoltaic measurements of cobalt complex sensitized solar cell show that the short-circuit current density (JSC), open-circuit voltage (VOC), fill factor (FF%) and photovoltaic conversion efficiency (PCE%) are 48.80 μA.cm-2, 0.7 V, 44% and 0.09% at the air mass 1.5 (100mW.cm-2) irradiation condition, respectively. The high light harvesting efficiency (LHE) (~61%) and high molar absorption coefficient of the cobalt complex dye (12,500 M-1.cm-1) were other optical advantages of the cobalt complex sensitized solar cell. The results indicate the quantum yield of electron injection (φing) which depends on dye structure as a parameter influences the JSC. The pyridine rings conformation in donor part of the cobalt complex dye plays a significant role in φing and subsequently PCE. These findings open a new insight about mechanistic aspects of dye sensitized solar cells efficiency.
关键词： Dye-sensitized solar cell,Photoanode,Dye,Counter electrode,Photovoltaic measurement,Cobalt complex
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Dye‐Sensitized Solar Cells: History, Components, Configuration, and Working Principle
摘要： The ever-growing human population requires the consumption of energy in various forms, and therefore researchers in energy field focus on energy harvesting from various sources. The nonrenewable energy sources such as fossil fuels are running out, which cannot be replenished in our life time. The nonrenewable energy sources are carbon-based fossil fuels such as coal, petroleum, and natural gas that emits greenhouse gases (for example carbon dioxide) that cause global warming, a serious threat to the world and mankind. At present, worldwide around three-fourth of the electricity is obtained from the nonrenewable sources that cannot be reused or recycled [1]. Many countries such as Japan, China, France, Ukraine, and India depend on nuclear power stations for the production of electricity and also they are facing several harmful issues from these power plants that lead to environmental pollution [2]. Therefore, the focus of scientists mainly rely on the renewable energy-based energy conversion devices. Solar, wind, hydroelectric, biomass, and geothermal are some of the examples of renewable energy resources available in our earth. Of these, solar energy is an important source of renewable energy, which is available throughout a day all over the year, basically inexhaustible in nature. In case of solar energy, radiation obtained from the sunlight is capable of producing heat and light, causes photochemical reactions, and generates electricity. As the electricity becomes a first and foremost basic need for the mankind, this impressive energy source can be utilized for the conversion of solar to electrical energy using solar cell technology. The strength of solar energy is magnanimous as it provides us about 10 000 times more energy that is higher than the world’s daily need of energy consumption [1]. The earth receives such a huge amount of energy every day, we are fortunate to harness it using suitable solar cell technologies. Regrettably, though solar energy is free of cost, the highly expensive technologies required for its conversion and storage which limit the technology to reach the wider community.
关键词： Dye-Sensitized Solar Cells,photoanode,TiO2,solar energy,dyes,photovoltaic effect,DSSCs,counter electrode,renewable energy,electrolytes
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Carbon Nanotubes‐Based Nanocomposite as Photoanode
摘要： Over the past few decades, energy is the backbone of technology and economic development. In addition to man, machine, and money, energy is now fourth factor of production. Without energy, no machine will run, electricity is needed for everything. Hence, our energy requirements have increased dramatically in the years following the industrial revolution. Readily accessible fossil fuels, such as coal, natural gas, and oils, are the major energy sources used to meet our current need. However, these sources are nonrenewable and have led to serious environmental issues, global warming, and air pollution, and their increasing consumption rate has accelerated fossil fuel depletion; the search for alternative energy source has become vital.
关键词： Dye-Sensitized Solar Cells,Photoanode,Renewable Energy,Nanocomposite,Carbon Nanotubes
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Graphene‐Based Nanocomposite as Photoanode
摘要： This chapter highlighted the research on the use of graphene and graphene-based nanocomposite materials in the photoanode of DSSCs. Graphene-based materials, such as pristine graphene, graphene oxide, and reduced graphene oxide and graphene quantum dots possess attractive properties for various components of DSSC photoanode. The graphene-based nanocomposite materials showed different functionalities such as electron conducting layer, transparent conducting electrode, and sensitizer in the DSSC photoanode. When combined with other nanomaterials of metal, metal oxides, metal sulfides, etc., to form a nanocomposite due to synergetic effects few interesting properties are also emerged which enhanced the photovoltaic performances of DSSCs. From the above discussion, it is clear that graphene and its nanocomposites have the properties that are well suited for the purpose of making high-performance photoanode for DSSC. But, there is still lake of extensive studies on the graphene-based nanocomposite materials in the DSSC photoanode as compared to the applications toward counter electrode. Hence, an in-depth research on modification of DSSC photoanode employing graphenebased materials needs to be carried out. Particularly, the synthesis protocols for graphene-based materials with tunable morphology and adjustable properties and their better incorporation into other components to enhance the photoanode performance. On the other hand, loading of graphene-based material on to the host also greatly influence the performance of the cells, hence meticulous calculation on the amount of materials and characterization of their physical and chemical properties can play important roles in solving many issues limiting the performance of DSSC photoanodes. When graphene is used as a transparent conducting electrode, the major issue is to maintain the transparency. The unsatisfactory transparency is caused by multiple-layer graphene stacking and the high sheet resistance due to surface defects and oxidization. Better processing procedures are necessary to overcome these problems and enhance the chance for graphene to be used as feasible alternatives to TCOs in the DSSC photoanode. The strength and flexibility of graphene outperforms other flexible candidates. Further modification of graphene nanosheets may create a new generation of flexible electrodes. Considerable progress has been made on the preparation of graphene transparent conducting electrodes at the laboratory level; however, it remains a challenge to cost-effectively produce high-quality graphene on an industrial scale for the practical use of graphene in transparent conducting electrodes.
关键词： photoanode,photovoltaic,nanocomposite,graphene,DSSC
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Function of Photoanode: Charge Transfer Dynamics, Challenges, and Alternative Strategies
摘要： The increase in population demanded heavy energy requirements that accelerated the depletion of fossil fuels [1]. Among several renewable resource-based alternatives, dye-sensitized solar cell (DSSC) is one of the cost-effective and potential substitutes to silicon solar cells that emerged in the early 1990s in the field of photovoltaics, as it involves inexpensive components and simple fabrication process. DSSC is entirely different from the conventional p/n junction solar cells in terms of operating principle; however, it adopts the principle of natural photosynthesis process and, therefore, is it is often addressed as artificial photosynthesis. The monolayer of dye molecules on the photoanode functions like chlorophyll in plants and absorbs the incident light to generate both positive and negative charge carriers in the cell.
关键词： photoanode,dye-sensitized solar cell,charge transfer dynamics,renewable energy,DSSC
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Function of <scp>TiCl</scp><sub/>4</sub> Posttreatment in Photoanode
摘要： Energy is the key factor for any living creature to exist in this universe. The advent of industrialization and increase in population have led to a surge in the crisis for energy. The reduction of our dependence on fossil fuels (oil, coal, and natural gas), as well as the evolution towards a cleaner future, requires the large deployment of sustainable renewable energy sources. Among them solar energy is the most abundant and also available throughout the year. Moreover, the solar energy has the greatest potential to fulfill the thirst for energy and the need for innovation of clean and eco-friendly technologies. In this perspective, developing solar cells is one of the best approaches to convert solar energy into electrical energy based on photovoltaic effect. Solar cells based on crystalline silicon and thin film technologies are often referred to as first- and second-generation solar cells. The demerits in that are the limited availability and the cost of silicon. An emerging third-generation photovoltaics have been developed as an alternate to it. These include Dye-sensitized solar cells (DSSCs), organic photovoltaic, quantum dots and recently perovskite solar cells. DSSCs based on nanocrystalline TiO2 as a photo-anode have attracted a lot of scientific and technological interest since their breakthrough in 1991 [1]. The two main functional aspects of charge generation and transport are no longer combined in one material but separated in different materials, i.e. a sensitizing dye, a wide-band-gap semiconductor (TiO2), and a liquid redox electrolyte [2].
关键词： photoanode,TiO2,dye-sensitized solar cells,electron transport,TiCl4 posttreatment,dye adsorption,photocurrent generation
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Plasmonic Nanocomposite as Photoanode
摘要： Semiconductor oxides used in dye-sensitized solar cell (DSSC) include TiO2, ZnO, SnO2, and Nb2O5 and the lists go on, which serve as the carrier for the monolayers of the sensitizer using their large surface and electron transfer to the conducting substrate. Nanocrystalline semiconductor films adsorb a large amount of the dye molecules and increase the harvesting efficiency of the solar energy. However, the major drawback associated with the use of large surface area TiO2 is its random electron transport, which will cause the electron–hole recombination process and hence affect the overall device performance [1, 2]. To overcome this problem, designing a photoanode with an efficient transport pathway from the photoinjected carriers to the current collector seems to be a possible alternative to enhance the performance of DSSCs. With this aim, surface modification with metal, doping, semiconductor coupling, and hybridizing with carbon material have been attempted [3–6]. Modification of metal oxide with plasmonic particles such as gold (Au) [7–9] and silver (Ag) [10, 11] were reported actively in the DSSC application to prevent the recombination of the photogenerated electron–hole pairs and improve the charge transfer efficiency.
关键词： photoanode,TiO2,ZnO,Au,Ag,dye-sensitized solar cells,Plasmonic nanocomposite
更新于2025-09-12 10:27:22
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Electrophoretic Deposition of Quantum Dots and Characterisation of Composites
摘要： Electrophoretic deposition (EPD) is an emerging technique in nanomaterial-based device fabrication. Here, we report an in-depth study of this approach as a means to deposit colloidal quantum dots (CQDs), in a range of solvents. For the first time, we report the significant improvement of EPD performance via the use of dichloromethane (DCM) for deposition of CQDs, producing a corresponding CQD-TiO2 composite with a near 10-fold increase in quantum dot loading relative to more commonly used solvents such as chloroform or toluene. We propose this effect is due to the higher dielectric constant of the solvent relative to more commonly used and therefore the stronger effect of EPD in this medium, though there remains the possibility that changes in zeta potential may also play an important role. In addition, this solvent choice enables the true universality of QD EPD to be demonstrated, via the sensitization of porous TiO2 electrodes with a range of ligand capped CdSe QDs and a range of group II-VI CQDs including CdS, CdSe/CdS, CdS/CdSe and CdTe/CdSe, and group IV-VI PbS QDs.
关键词： dichloromethane,sensitization,photoanode,quantum dots,electrophoretic deposition
更新于2025-09-12 10:27:22
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Enhanced light harvest in dye-sensitized solar cells by nanocrystals-on-microcrystals TiO <sub/>2</sub> photoanode
摘要： In this paper, we discuss the new design of a DSSC using a photoanode by inserting TiO2 particles in size of sub-micron into the photoanode with small nanoparticles. The experimental results point out that the uniform mixing of TiO2 nanoparticles can increase the photocurrent density, and then obviously improve the ef?ciency of DSSC. The best performance was achieved when the mass ratio of sub-micron particles was 5%, and the power conversion ef?ciency was 5.58%, which is 20% higher than pure TiO2 nanoparticles. This nanocrystals-on-microcrystals TiO2 photoanode can be used in DSSC with high yield for large-scale production.
关键词： photoanode,photoelectric conversion ef?ciency,dye-sensitized solar cell
更新于2025-09-12 10:27:22