A system for the synthesis of Ti1-xFexO2-δ photoelectrodes sensitized with CdS QDs-N719 dye

Abstract

A system (100) for synthesizing Ti 1-x Fe x O 2-δ -Photoelectrodes co-sensitized with the dye CdS QDs-N719, comprising: i) a nanoparticle synthesis apparatus (102) configured to synthesize Ti 1-x Fe x O 2-δ -To synthesize nanoparticles with an x-value in the range of 0.008 to 0.024, wherein the synthesis arrangement comprises: a) a primary mixing chamber (104) configured to mix titanium isopropoxide (TTIP) with anhydrous isopropanol and sodium dodecyl sulfate (SDS); b) a doping addition unit (106) configured to add a stoichiometric amount of an iron(III) nitrate nonahydrate solution in isopropanol to the primary mixing chamber (104); c) a pH control module (108) configured to add aqueous ammonia dropwise to maintain the pH at 9.00 ±0.10; d) a stirring module (110) connected to the primary mixing chamber (104) and configured to maintain continuous stirring for a certain period of time; e) a collection unit (112) connected to the primary mixing chamber (104) and configured to filter and collect white titanium hydroxide precipitate; f) a drying and calcining unit (114) configured to dry and calcine the precipitation at 450°C for 2 hours; ii) a photoelectrode manufacturing arrangement (200) comprising the following: a) a paste manufacturing unit (202) configured to Ti 1-x Fe x O 2-δ -Disperse nanoparticles sequentially in DMF and acetonitrile solvents; b) a coating module (204) configured to apply the paste evenly onto an FTO substrate to produce films which are then sintered; c) a sensitization arrangement (206) configured to sensitize the prepared sintered films successively with CdS quantum dots and N719 dye, together with ZnS deposition, wherein the sensitization arrangement first deposits CdS-QDs onto the films, then deposits a ZnS layer, and then deposits N719 dyes onto the surface of the modified Ti 1-x Fe x O2- δ -QDs films depositing ZnS particles; and d) a washing unit (208) comprising a detergent containing an equimolar mixture of tert-butyl alcohol and acetonitrile for washing the prepared electrodes to obtain uniform photoelectrodes.

Description

FIELD OF THE INVENTION

[0001] The present disclosure relates to a system for synthesizing Ti 1-x Fe x O 2-δ -photoelectrodes co-sensitized with CdS QDs-N719 dye. More specifically, the present invention relates to a system for synthesizing Ti 1-x Fe x O 2-δ Nanoparticles (NPs) with different contents of Fe(III) ions and subsequent coupling of the synthesized nanoparticles with CdS quantum dots, followed by sensitization with N719 units for photovoltaic measurements. BACKGROUND OF THE INVENTION

[0002] The modification of titanium dioxide (TiO2) through doping has proven effective in altering its optical and electrical properties, making the material valuable for various applications, including catalysis, organic conversion, and solar energy generation. In particular, the introduction of dopants such as Fe3+ -ions in TiO2 has potential advantages due to the electronic compatibility and the similar ion size of Fe 3+ (69 pm) and Ti 4+ (74.5 pm), enabling substitutable solid solutions. Fe-doped TiO2 (Fe@TiO2) has shown promising results in certain applications. For example, Fe@TiO2 nanotubes have improved photodynamic efficiency and biocompatibility in cancer treatment studies, while Fe@TiO2 nanoparticles exhibit increased photocatalytic activity against bacteria under certain light conditions, mainly due to their smaller particle size and reduced band gap.

[0003] Despite these advances, however, significant challenges remain in achieving efficient energy conversion. For example, the solar efficiency of Fe@TiO2-based devices is generally low, which can be attributed to issues with charge transfer and device connectivity, leading to suboptimal photovoltaic performance. Studies on Fe@TiO2 photoelectrodes in dye-sensitized solar cells (DSSCs) have shown that tuning optical properties alone is not sufficient; poor performance metrics such as fill factor and open-circuit voltage limit overall efficiency. Furthermore, harsh conditions are often required to achieve a morphology that enables improved energy conversion, posing practical difficulties in material preparation.

[0004] Given these challenges, there is a need for a more comprehensive technique to improve TiO2-based materials for solar applications. This invention overcomes these limitations by developing a system that 1-x Fe x O 2-δ -Photoelectrodes co-sensitized with the dye CdS QDs-N719 were synthesized, with the synthesized electrodes aiming to overcome current inefficiencies, provide enhanced photovoltaic properties, and improve the applicability of TiO2-based materials in DSSCs. SUMMARY OF THE INVENTION

[0005] The present disclosure relates to a system for synthesizing Ti 1-x Fe x O 2-δ -Photoelectrodes co-sensitized with CdS QDs-N719 dye. The invention comprises the synthesis of Ti 1-x Fe x O 2-δnanoparticles with different Fe(III) contents (x = 0.008 to 0.024 and δ = 0.5x) using a sol-gel process at room temperature. These nanoparticles were bonded to CdS quantum dots and sensitized with N719 dye for photovoltaic applications. The Ti 1-x Fe x O 2-δ Powder was mixed in DMF and acetonitrile solvents and then coated onto F:SnO2 (FTO) glass substrates using a binder-free doctor blade technique. After calcination, the photoelectrodes were sensitized with CdS QDs, N719 dye, or both. The resulting DSSCs with Ru-based N719 dye deposited on Ti 1-x Fe x O 2-δ - CdS QDs photoanodes with Pt counter electrodes and I - / I3 - - electrolyte anchored, achieved a conversion efficiency of 3.48%, 1.5 times higher than undoped TiO2.

[0006] The present disclosure relates to a system for synthesizing Ti 1-x Fe x O 2-δ -photoelectrodes co-sensitized with the dye CdS QDs-N719. The system comprises: a nanoparticle synthesis array configured to 1-x Fe x O 2-δ-nanoparticles with an x-value in the range of 0.008 to 0.024 were synthesized, the synthesis assembly comprising: a primary mixing chamber configured to mix titanium isopropoxide (TTIP) with anhydrous isopropanol and sodium dodecyl sulfate (SDS); a dopant addition unit configured to add a stoichiometric amount of a ferric nitrate nonahydrate solution in isopropanol to the primary mixing chamber; a pH control module configured to dropwise add aqueous ammonia to maintain the pH at 9.00 ± 0.01.10; a stirring module connected to the primary mixing chamber and configured to maintain continuous stirring for a specified period of time; a collection unit connected to the primary mixing chamber and configured to filter and collect white precipitate of titanium hydroxide; and a drying and calcination unit configured to dry and calcine the precipitate at 450°C for 2 hours. The system further includes: a photoelectrode manufacturing assembly comprising: a paste manufacturing unit configured to produce Ti. 1-x Fe x O 2-δNanoparticles are sequentially dispersed in DMF and acetonitrile solvent; a coating module configured to evenly deposit the paste on an FTO substrate to produce films that are then sintered; a sensitization assembly configured to sequentially sensitize the prepared sintered films with CdS quantum dots and N719 dye, together with ZnS deposition, wherein the sensitization assembly first deposits CdS QDs on the films, then deposits a ZnS layer, and subsequently combines N719 dyes with ZnS particles on the surface of the modified Ti 1-x Fe x O 2-6 -CdS QD film; and a washing unit comprising a washing agent containing an equimolar mixture of tert-butyl alcohol and acetonitrile to wash the prepared electrodes to obtain uniform photoelectrodes.

[0007] In one embodiment, the sensitization assembly comprises: a PDDA coating unit configured to apply 2% PDDA with 0.5 M NaCl; a quantum dot deposition unit configured to apply CdS quantum dots by spin coating; a ZnS layer deposition unit configured to apply a ZnS layer on a Ti 1-x Fe x O 2-δ -CdS film;an N719 dye deposition unit used to anchor the N719 dyes on the surface of the modified Ti 1-x Fe x O 2-δ -CdS QD films; a washing module configured to rinse the films with double-distilled water; and an intermediate drying unit configured to dry the films at 110°C for 15 minutes.

[0008] In one embodiment, the system further comprises a cell mounting unit comprising a mounting unit configured to mount the cell mounted on a Ti 1-x Fe x O 2-δ -CdS QDs electrode anchored N719 dye molecule as the working electrode and platinized / FTO as the counter electrode in a sandwich cell using a 60 µm Surlyn spacer, wherein the cell assembly further comprises: an electrolyte injection port configured to introduce a drop of electrolyte through the hole from the Pt counter electrode; and a vacuum chamber enabling uniform electrolyte loading.

[0009] In one embodiment, the prepared nanoparticles are characterized to evaluate their physical, chemical and optical properties.

[0010] In one embodiment, the fabricated photoelectrodes are subjected to an evaluation of their photovoltaic performance for different compositions of Ti 1-x Fe x O 2-δ nanoparticles co-sensitized with CdS QDS and N719 dye.

[0011] An object of the present disclosure is to provide a system for synthesizing Ti 1-x Fe x O 2-δ -photoelectrodes co-sensitized with the dye CdS QDs-N719.

[0012] Another aim of the present invention is to improve the photovoltaic efficiency of TiO2-based DSSCs by doping with Fe(III) ions and co-sensitization with CdS QDs and N719 dye.

[0013] Another object of the present invention is to achieve improved charge transfer and lower recombination losses in the TiO2 photoelectrode by a binder-free deposition technique on FTO glass.

[0014] Another object of the present invention is to extend the light absorption in the visible range by using the Ti 1-x Fe x O 2-δ -photoelectrode is co-sensitized with both CdS QDs and the dye N719.

[0015] Another object of the present invention is to provide 2-nanoparticles with controlled Fe content at room temperature.

[0016] Another object of the present invention is to improve the overall stability and photovoltaic performance of DSSCs by using optimized Ti 1-x Fe x O 2-δ -Compositions and innovative techniques for the production of photoelectrodes.

[0017] To further clarify the advantages and features of the present disclosure, a more detailed description of the invention will be given with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. It should be noted that these drawings represent only typical embodiments of the invention and are therefore not to be considered limiting its scope. The invention will be described and explained in additional detail and in greater detail with reference to the accompanying drawings. SHORT DESCRIPTION OF THE FIGURE

[0018] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout. Where: Fig. 1 shows a block diagram of a system for the synthesis of Ti 1-xFe x O 2-δ -Photoelectrodes co-sensitized with the dye CdS QDs-N719 according to an embodiment of the present disclosure.

[0019] Furthermore, those skilled in the art will appreciate that elements in the drawings are shown for convenience and may not necessarily be drawn to scale. For example, the flowcharts illustrate the method by key steps to enhance understanding of aspects of the present disclosure. Furthermore, with respect to device construction, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawing may show only the specific details relevant to understanding embodiments of the present disclosure in order not to clutter the drawings with details that would be readily apparent to those skilled in the art who would benefit from the description herein. DETAILED DESCRIPTION:

[0020] To facilitate an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and described in specific language. It is to be understood, however, that no limitation on the scope of the invention is intended thereby, since such changes and further modifications of the illustrated system, and such further applications of the principles of the invention as illustrated therein, are contemplated as would normally occur to one skilled in the art to which the invention pertains.

[0021] It will be understood by one skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting thereof.

[0022] References in this specification to "one aspect," "another aspect," or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, occurrences of the phrase "in one embodiment," "in another embodiment," and similar language throughout this specification may or may not all refer to the same embodiment.

[0023] The terms "comprises," "comprising," or other variations thereof are intended to cover non-exclusive inclusion, such that a process or method comprising a list of steps not only includes those steps, but may also include other steps not expressly listed or inherent in such process or method. Likewise, one or more devices or subsystems or elements or structures or components preceded by "comprises...a" does not preclude, without further limitation, the existence of other devices or other subsystems or other elements or other structures or other components or additional devices or additional subsystems or additional elements or additional structures or additional components.

[0024] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are for illustrative purposes only and should not be considered limiting.

[0025] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0026] Fig. 1 shows a block diagram of a system (100) for synthesizing Ti 1-x Fe x O 2-δ -Photoelectrodes co-sensitized with the dye CdS QDs-N719 according to an embodiment of the present disclosure.

[0027] With reference to Fig. 1, the system (100) comprises a nanoparticle synthesis assembly (102) configured to produce Ti 1-x Fex O 2-δ-nanoparticles with x in the range of 0.008 to 0.024 are synthesized, the synthesis assembly comprising: a primary mixing chamber (104) configured to mix titanium isopropoxide (TTIP) with anhydrous isopropanol and sodium dodecyl sulfate (SDS); a dopant addition unit (106) configured to add a stoichiometric amount of a ferric nitrate nonahydrate solution in isopropanol to the primary mixing chamber (104); a pH control module (108) configured to add aqueous ammonia dropwise to maintain the pH at 9.00 ± 0.00.10; a stirring module (110) connected to the primary mixing chamber (104) and configured to maintain continuous stirring for a predetermined period of time; a collecting unit (112) connected to the primary mixing chamber (104) and configured to filter and collect white precipitate of titanium hydroxide; and a drying and calcining unit (114) configured to dry the precipitate and anneal it at 450°C for 2 hours. The system (100) further comprises: a photoelectrode manufacturing assembly (200) comprising: a paste manufacturing unit (202) configured to produce Ti. 1-x Fe x O 2-δNanoparticles are sequentially dispersed in DMF and acetonitrile solvent; a coating module (204) configured to deposit the paste evenly on an FTO substrate to produce films, which are then sintered; a sensitization assembly (206) configured to sequentially sensitize the produced sintered films with CdS quantum dots and N719 dye, together with ZnS deposition, wherein the sensitization assembly first deposits CdS QDs on the films, then a ZnS layer is deposited, and then N719 dyes with ZnS particle deposition on the surface of the modified Ti 1-x Fe x O 2-δ -CdS- QD film are deposited; and a washing unit (208) comprising a washing agent containing an equimolar mixture of tert-butyl alcohol and acetonitrile to wash the prepared electrodes to obtain uniform photoelectrodes.

[0028] In one embodiment, the sensitization assembly (206) comprises: a PDDA coating unit (206a) configured to apply 2% PDDA with 0.5 M NaCl; a quantum dot deposition unit (206b) configured to apply CdS quantum dots by spin coating; a ZnS layer deposition unit (206c) configured to apply a ZnS layer on a Ti 1-x Fe x O 2-δ --CdS film; an N719 dye deposition unit (206d) used to anchor the N719 dyes on the surface of the modified Ti 1-x Fe x O 2-δ --CdS-QD films; a washing module (206e) configured to rinse the films with double distilled water; and an intermediate drying unit (206f) configured to dry the films at 110°C for 15 minutes.

[0029] In one embodiment, the system (100) further comprises a cell assembly unit (300) comprising an assembly unit (302) configured to assemble the N719 dye molecule attached to a Ti 1-x Fe x O 2-δ --CdS QDs electrode anchored as the working electrode and platinized / FTO as the counter electrode, into a sandwich cell using a 60 µm Surlyn spacer. The cell assembly unit (300) further comprises: an electrolyte injection port (304) configured to introduce a drop of electrolyte through the hole from the Pt counter electrode; and a vacuum chamber (306) that allows uniform electrolyte loading.

[0030] In one embodiment, the prepared nanoparticles are characterized to evaluate their physical, chemical and optical properties.

[0031] In one embodiment, the fabricated photoelectrodes are subjected to an evaluation of their photovoltaic performance for different compositions of Ti 1-x Fe x O 2-δ nanoparticles co-sensitized with CdS QDS and N719 dye.

[0032] The present invention relates to a system for the synthesis of Ti 1-x Fe x O 2-δ Nanoparticles (NPs) with varying Fe(III) ion contents (x = 0.008 to 0.024 and δ = 0.5x) and the subsequent coupling of the synthesized nanoparticles with CdS quantum dots, followed by sensitization with N719 units, to produce photoelectrodes for photovoltaic measurements. The synthesized nanoparticles were first characterized with regard to their chemical, physical, and optical properties, and after characterization, the powder form of Ti was 1-x Fe x O 2-δThe binder-free paste was thoroughly mixed with DMF solvent and then with CH3CN solvent using an ultrasonic device. The binder-free paste was then coated onto a transparent conductive oxide glass substrate F:SnO2 (FTO) using a doctor blade technique to obtain a uniform photoelectrode. After calcination, the various photoelectrodes were subsequently sensitized with either CdS QDs or N719 dye, or both.

[0033] In one embodiment, the proposed system includes a nanoparticle synthesis assembly suitable for the synthesis of Ti 1-x Fe x O 2-δ(x = 0.008 to 0.024), the assembly containing multiple units that collectively utilize the sol-gel technique to synthesize nanoparticles. First, TTIP was added to anhydrous isopropanol with sodium dodecyl sulfate (SDS) as a capping molecule. The contents were stirred for 15 minutes at room temperature. As an Fe dopant source, a stoichiometric amount of ferric nitrate nonahydrate was dissolved in isopropanol, and this solution was added to the above mixture, and the whole solution was stirred for 2 hours. An aqueous ammonia solution was added dropwise until the pH of the solution reached 9.00 ± 0.10 to form a white precipitate of titanium hydroxide. The mixture was continuously stirred for 2 hours and filtered to separate the precipitate. The collected precipitate was then washed with isopropanol and then with double-distilled water, and finally dried in an electric oven.After annealing at 450 °C for 2 hours, a white, crystalline, doped / undoped TiO 2 powder was obtained.

[0034] In one embodiment, the system includes a photoelectrode fabrication assembly suitable for the development and manufacture of Ti l1-x Fe x O 2-δ -CdS QDs-N719 dye photoelectrodes. The assembly contains several units for carrying out the production, whereby first the synthesized nanoparticles are used to prepare the paste from the nanoparticles, wherein the Ti 1-x Fe x O20.5 x -Paste by dispersing Ti 1-x Fe x O 2-δNPs in DMF and then in acetonitrile as a solvent. The prepared paste was applied to an FTO substrate using a doctor blade technique, and then the films were sintered at 450 °C for 30 minutes. These films were then immersed in a 2% PDDA solution containing 0.5 M NaCl at room temperature and then rinsed with double-distilled water. CdS QDs (S1, ESI + ) are deposited on the same surface by spin coating. Then the modified Ti1 - xFe x O 2-δ -CdS films are rinsed with double distilled water and dried in an oven at 110 °C for 15 minutes. However, for better charge transport, a ZnS layer is deposited on the Ti 1-x Fe x O 2-δ -C d S-film deposited. CdS-sensitized Ti 1-x Fe xO2-δ thin films were immersed in an aqueous solution of Zn(CH3CO2)2 for 1 minute, rinsed thoroughly with double distilled water, and then immersed in an aqueous solution of Na2S (0.5 M) for 1 minute. Furthermore, this process was repeated five times to ensure uniform deposition of ZnS particles on the Ti 1-x Fe x O 2-δ -CdS films. These electrodes are then sintered at 250 °C for 30 minutes. Finally, the N719 dyes are deposited on the surface of the modified Ti1- x Fe x O 2-δ CdS QD films were anchored by immersing the films in an N719 dye solution for 24 hours. These electrodes were then washed with an equimolar mixture of tert-butyl alcohol and acetonitrile (1:1 ratio) to obtain a uniform photoelectrode and remove the unbound dye. - solar cell, wherein the assembly contains several units for carrying out the production. First, the solar cell was 1-x Fe x O 2-δ The N719 dye molecule anchored to the CaS QD electrode as the working electrode and platinized FTO as the counter electrode were assembled into a sandwich cell by sealing with a thick Surlyn spacer (60 µm) at 110 °C to properly bond the two electrodes. The photoactive area of ​​the Ti1-xFexO2 -δ- The CdS-N719 electrode is held at 0.36 cm2. A drop of electrolyte is introduced through the hole of the Pt counter electrode. The cell is placed in a vacuum chamber to ensure uniform electrolyte loading throughout the device.

[0035] The optical properties of undoped Ti 1-x Fe x O 2-δ - and CdS-sensitized Ti 1-x Fe x O 2-δ-CdS thin films were measured using UV-Vis diffuse reflectance spectra (DRS). The evaluation of the Fe-doped TiO 2 -based photoanodes shows that increasing the Fe content from 0.008 to 0.024 mol% significantly reduces the absorption edge of Ti 1-x Fe x O 2-δ towards the visible spectrum, as evidenced by a redshift of the optical absorption and a reduced band gap. CdS sensitization further extends the absorption range from 350 to 550 nm and enhances the absorption of visible light, likely due to the high molar extinction coefficient of CdS.

[0036] Fourier transform infrared spectroscopy (FTIR) of undoped TiO2, Ti 0.992 Fe 0.008 O 1.996 and Ti 0.976 Fe 0.024 O 1.988 and PDDA-loaded Ti 0.976 Fe 0.024 O 1.988NPs were analyzed. FTIR analysis confirmed increased surface hydroxylation in Fe-doped TiO 2 , which facilitates the deposition of negatively charged CdS QDs without disturbing the anatase structure of TiO 2 .

[0037] The structural properties of undoped TiO 2 -, Ti 0.992 Fe 0.008 O 1.996 -, Ti 0.984 Fe 0.016 O 1.992 -, Ti 0.976 Fe 0.024 O 1.988 - as well as (Ti 0.976 Fe 0.024 O 1.988 - CdS thin films were analyzed by X-ray diffraction (XRD). XRD analysis shows that Fe ions are successfully incorporated into the TiO 2 lattice without forming separate Fe phases, with crystallite sizes of undoped and Fe-doped TiO 2 NPs in the range of 15-20 nm. It was confirmed that CdS QDs (2-4 nm) are deposited on different layers.

[0038] The surface morphology of CdS QDs, Ti 0.976 Fe 0.024 O1.988 and Ti 0.976 Fe 0.024 O 1.988 - CdS film is examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM analyses show that CdS QDs have a uniform spherical morphology and the Ti 0.976 Fe 0.024 O 1.988 - Successfully decorate film, optimizing the surface for improved interaction with CdS.

[0039] XPS was used to determine the chemical bonding configuration on the surface of Ti 0.976 Fe 0.024 O 1.988 and Ti 0.976 Fe 0.024 O 1.988 - to investigate CdS photoanodes. High-resolution XPS spectra confirm the presence and oxidation states of Ti, O, Cd, S, and Fe, thus verifying the successful coupling of CdS QDs on Fe-doped TiO2. Mott-Schottky analysis was used to examine the semiconductor properties and the associated donor density of the undoped and Fe-doped TiO2 film. The Mott-Schottky analysis indicates n-type semiconductor behavior for both undoped and Fe-doped TiO2, with the flat band potential shifting from -0.254 V to -0.534 V with increasing Fe concentration. The donor density also increases with Fe content, indicating an increased charge carrier density in the TiO2 layer.

[0040] These results together confirm that Fe doping and CdS sensitization improve the optical and semiconductor properties of TiO2, thus increasing its potential efficiency in photovoltaic applications.

[0041] The evaluation of the Ti 1-x Fe x O 2-δFilms showed significant improvements in photovoltaic performance at different Fe doping concentrations. Devices made of undoped TiO2 sensitized with CdS QDs and N719 dye achieved a conversion efficiency of about 2%. In contrast, TiO2 films doped with Fe(III) ions and co-sensitized with CdS QDs and N719 dye achieved higher solar efficiencies, with Ti 0.992 Fe 0.008 O 1.996 :CdS:N719 achieved the highest efficiency of 3.48%, which is approximately 1.5 times that of undoped TiO 2 . This improvement was attributed to the increase in short-circuit current density (Jsc) and a higher donor density (ND) for Ti0.992Fe0.008O1.996, as well as a more negative flat-band potential compared to other dopant levels, thus optimizing charge transport and energy conversion.

[0042] Furthermore, the fill factor (FF) increased from 42% for undoped devices to 52% for Fe-doped devices, indicating improved charge transport efficiency. The observed improvements in photovoltaic parameters such as Voc, Jsc, FF, and overall efficiency demonstrate the potential of Ti 1-x Fe x O 2-6 -NPs as promising photoelectrodes for high-performance dye-sensitized solar cells (DSSCs) and other photoenergy conversion applications.

[0043] The drawings and the foregoing description provide examples of embodiments. Those skilled in the art will recognize that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be separated into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of the processes described herein may be changed and are not limited to the manner described herein. Furthermore, the actions of any flowchart need not be implemented in the order shown; nor do all actions necessarily need to be performed. Also, those actions that are not dependent on other actions may be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples.Numerous variations, whether explicitly stated in the specification or not, such as differences in structure, dimensions, and material use, are possible. The scope of the embodiments is at least as broad as indicated in the following claims.

[0044] Advantages, other benefits, and solutions to problems have been described above with reference to specific embodiments. However, the advantages, benefits, solutions to problems, and any components that may cause an advantage or solution to occur or become more apparent are not to be construed as a critical, required, or essential feature or component of any or all of the claims. REFERENCES 100 A system (100) for the synthesis of Ti 1-x Fe x O 2-δ -Photoelectrodes co-sensitized with the dye CdS QDs-N719. 102 Arrangement for the synthesis of nanoparticles 104 Primary mixing chamber 106 dopant addition unit 108 pH control module 110 Stirring module 112 Catch device 114 Drying and calcination unit 200 Photoelectrode manufacturing assembly 202 Paste preparation unit 204 Coating module 206 Awareness Unit 206a PDDA coating unit 206b Quantum dot coating unit 206c Unit for the deposition of ZnS layers 206d Unit for the deposition of N719 dyes 206e washing module 206f intermediate drying unit 208 washing unit 300 units for cell assembly 302 Assembly unit 304 Electrolyte injection port 306 Vacuum Chamber

Claims

[1] A system (100) for synthesizing Ti 1-x Fe x O 2-δ -Photoelectrodes co-sensitized with the dye CdS QDs-N719, comprising: i) a nanoparticle synthesis apparatus (102) configured to synthesize Ti 1-x Fe x O 2-δ -To synthesize nanoparticles with an x-value in the range of 0.008 to 0.024, wherein the synthesis arrangement comprises: a) a primary mixing chamber (104) configured to mix titanium isopropoxide (TTIP) with anhydrous isopropanol and sodium dodecyl sulfate (SDS); b) a doping addition unit (106) configured to add a stoichiometric amount of an iron(III) nitrate nonahydrate solution in isopropanol to the primary mixing chamber (104); c) a pH control module (108) configured to add aqueous ammonia dropwise to maintain the pH at 9.00 ±0.10; d) a stirring module (110) connected to the primary mixing chamber (104) and configured to maintain continuous stirring for a certain period of time; e) a collection unit (112) connected to the primary mixing chamber (104) and configured to filter and collect white titanium hydroxide precipitate; f) a drying and calcining unit (114) configured to dry and calcine the precipitation at 450°C for 2 hours; ii) a photoelectrode manufacturing arrangement (200) comprising the following: a) a paste manufacturing unit (202) configured to Ti 1-x Fe x O 2-δ -Disperse nanoparticles sequentially in DMF and acetonitrile solvents; b) a coating module (204) configured to apply the paste evenly onto an FTO substrate to produce films which are then sintered; c) a sensitization arrangement (206) configured to sensitize the prepared sintered films successively with CdS quantum dots and N719 dye, together with ZnS deposition, wherein the sensitization arrangement first deposits CdS-QDs onto the films, then deposits a ZnS layer, and then deposits N719 dyes onto the surface of the modified Ti 1-x Fe x O2- δ -QDs films depositing ZnS particles; and d) a washing unit (208) with a detergent containing an equimolar mixture of tert-butyl alcohol and acetonitrile for washing the prepared electrodes to obtain uniform photoelectrodes. [2] System (100) according to claim 1, wherein the sensitization arrangement (206) comprises: i) a PDDA coating unit (206a) configured to deposit 2% PDDA with 0.5 M NaCl; ii) a quantum dot deposition unit (206b) configured to deposit CdS quantum dots by spin coating; iii) a ZnS layer deposition unit (206c) configured to deposit a ZnS layer on a Ti 1-x Fe x O 2-δ -to separate CdS film; iv) an N719 dye deposition unit (206d) configured to deposit the N719 dyes onto the surface of the modified Ti 1-x Fe x O 2-δ -to anchor CdS-QD-Films; v) a washing module (206e) configured to rinse the films with double distilled water; and vi) an intermediate drying unit (206f) configured to dry the films for 15 minutes at 110°C. [3] System (100) according to claim 1, further comprising a cell assembly unit (300) with an assembly unit (302) configured to mount the on a Ti1- x Fe x O2-δ -CdS QDs electrode anchored N719 dye molecule as working electrode and platinized FTO as counter electrode assembled into a sandwich cell using a 60 µm Surlyn spacer. [4] System (100) according to claim 3, wherein the cell assembly unit (300) further comprises: i) an electrolyte injection port (304) configured to introduce a drop of electrolyte through the hole from the Pt counter electrode; and ii) a vacuum chamber (306) which enables uniform electrolyte loading. [5] System (100) according to claim 1, wherein the produced nanoparticles are characterized in order to evaluate their physical, chemical and optical properties. [6] System (100) according to claim 1, wherein the manufactured photoelectrodes are subject to an evaluation of their photovoltaic performance for different compositions of Ti 1-x Fe x O 2-δ-subjected to nanoparticles co-sensitized with CdS QDS and N719 dye.

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