CdS Sensitizer Research Articles

Self-powered photodetector based on 1D TiO2-3D CdS mixed dimensional heterostructure fabricated at low temperature

Solution processed photodetectors have garnered great attention in applications such as, machine vision perception, neuromorphic computing and opto-electronic memory storage. Though, such photodetectors offer several advantages such as ease of fabrication, high scalability, low thermal budget and low-cost processing, multi-modal functionality etc. however, they suffer from the major drawback of inferior device performance −as low responsivity and slow rise time, particularly due to the intrinsic poor crystallinity of the photoactive material. In this work, we demonstrate a solution processed photodetector with impressive performance at comparatively low processing temperatures (<150 °C) based on the mixed dimensional heterostructure configuration of 1D TiO2 nanorods and 3D CdS nanoflowers. TiO2 nanorods have been synthesized by hydrothermal technique, whereas their CdS sensitization is done by chemical bath deposition. Low cost carbon paste is used as electrode instead of conventional non-economic noble metal electrodes. X-ray diffraction studies validated excellent crystallinity of the photoactive material even under low temperature processing condition. The type-II Heterojunction (TiO2 and CdS) configuration photodetector shows efficient response at zero bias, thus yielding a self-powered device. The detector shows response in UV and visible region, with excellent responsivity of 110 mA/W (5 V), 563 µA/W (0 V) and a quicker rise time of 81 ms. Albeit the simple fabrication scheme and low processing temperatures, the detector exhibited promising figures-of-merit, which aids in fabrication of novel solution processed photodetectors.

Construction of CdS/Ti-Nb-O composite photoanode with favorable optical absorption and charge transfer for dramatically boosted photoelectrochemical water splitting

Rational design and construction of highly effective Ti-based photoanodes with advantageous structures are crucial to enhance photoelectrochemical (PEC) water splitting. In this work, we reported a CdS/Ti-Nb-O composite photoanode with satisfactory charge transfer and optical absorption for dramatically boosted PEC performance, which was constructed by bulk-phase Nb-doping synergistically with CdS quantum dots (QDs) sensitization of Ti-based oxide nanostructures. The composite system exhibited a remarkable photocurrent density of 16.11 mA cm-2, which was 34 times higher than pure TiO2 (0.47 mA cm-2). The electron lifetime was substantially increased and the solar-to-hydrogen (STH) conversion efficiency could be as high as 9.45%. Bulk-phase Nb-doping improved the conductivity of Ti-Nb-O, which enabled speedy and sustained charge separation in the composite-electrolyte solid-liquid interface. Meanwhile, CdS sensitization extended light absorption from 410 nm to 640 nm, thereby generating more photogenerated carriers. Simultaneously, Nb-doping negatively shifted the valence band (VB) and conduction band (CB) of Ti-Nb-O, which made the energy band more compatible with CdS. And the well-matched energy band structures of CdS and Ti-Nb-O not only improved separation-transfer properties of photogenerated electrons and holes but also increased overall optical absorption property of the composite system. This work involved dual-regulation charge separation strategy through bulk-phase doping synergetically with QDs sensitization may contribute to constructing high-efficient Ti-based photoanodes for PEC water splitting.

Influence of CdS sensitization on the photovoltaic performance of CdS:TiO2 solar cell

Influence of CdS sensitization on the photovoltaic performance of CdS:TiO2 solar cell

CdS/CeO2 heterostructures as visible-light photocatalysts for the reduction of nitro to amine organics

We developed an easy-operation synthetic methodology to one-dimensional CdS/CeO2 heterostructures, which were formed by hybriding the CeO2 nanorods and CdS nanoparticles with varied mass loading of CdS. The heterostructures will be an ideal candidate as superior photocatalysts owing to their composite and structural features. We took the reduction of nitro organics with various substituents as probing reactions to evaluate their photocatalytic performances. As expect, the CdS/CeO2 heterostructures exhibit significantly enhanced and composition-dependent photocatalytic activity under visible-light illumination. Based on our systematic investigations, we ascribed the significantly improved visible-light harvesting properties to the hybriding of narrow-bandgap CdS with CeO2 and the negative potential of the conductive edge benefits for the reduction of H+ to active hydrogen species. More importantly, the CdS sensitization effect accelerates the interface carrier separation and transfer processes due to the formation of heterostructure. The life time of the photogenerated electrons are remarkably prolonged. Moreover, the 3-CdS/CeO2 composites also exhibit excellent photocatalytic stability.

Charging a vanadium redox battery with a photo(catalytic) fuel cell

A Photo(catalytic) Fuel Cell based on a CdS/TiO2 photoanode and using ethanol as model fuel has been studied as an electric power source to charge a vanadium redox battery. The Photo Fuel Cell was tested under various current production conditions in terms of stability and power output capacity. The cell was functional and produced substantial electric power by consuming an organic fuel under simulated solar energy irradiation. However, it has been found that CdS sensitizer may undergo a self-oxidation process which is relatively fast when the current output is large but is much slower when the current production is low. The conditions for slow self-oxidation have thus been delimited and this allowed determining the conditions for charging the vanadium redox battery using electricity produced by the Photo Fuel Cell. These findings set the basis for production of sustainable electricity and for its storage in a vanadium redox battery.

Vacancies induced enhancement in neodymium doped titania photoanodes based sensitized solar cells and photo-electrochemical cells

Herein we present a comprehensive study of composition dependent Neodymium (Nd3+) doped Titania (Nd-TiO2) as photoanodes for obtaining improved performances in different types of solar energy conversion devices, namely dye-sensitized solar cell (DSSC), quantum-dot (QD) sensitized solar cells (QDSC) and photo-electrochemical cells (PEC). An all-inclusive characterization of the optical, dielectric properties and morphological studies of Nd-TiO2 with different doping concentration are performed. The XPS and Urbach energy analysis corroborated further by the dielectric studies established the critical role of vacancies in the improved electrical properties of doped TiO2 in comparison with that of undoped TiO2. Superior performances on solar cells devices (DSSC and QDSC) and PEC water splitting devices using N719 dye and CdS-QD sensitized Nd-TiO2 photoanodes were fabricated and analyzed. Enhanced photo-conversion efficiencies of ≈30% for QDSC and ≈16% for DSSC were obtained with Nd (0.4 mol%)-TiO2 photoanodes in comparison with undoped TiO2 photoanodes. Similarly, the PEC water splitting of CdS (QDs) sensitization exhibited the photocurrent density of (1.8 mA-cm−2 at 1.23 V vs RHE), which is three times higher than undoped TiO2, while the N719 dye-sensitized photoanode exhibited the current density of (0.7 mA-cm−2 at 1.23 V vs RHE), which is two times higher than undoped TiO2. The results established that the optimized doping concentration of Nd (0.4 mol%)-TiO2 is universal for all classes of solar energy conversion devices.

Performance of pyrocatechol violet and carminic acid sensitized ZnO/CdS nanostructured photoactive materials for dye sensitized solar cell

In this study, ZnO and CdS deposited ZnO nanostructured material was successfully synthesized by using co-precipitation and ultra-sonication methods, respectively. A comparative study of the sensitization of ZnO and nanostructured ZnO/CdS with two different dyes (carminic acid and pyrocatechol violet) and applications of the synthesized material in solid state dye sensitized solar cells (DSSCs) are reported here. The characterization of the materials was performed by using x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The SEM and TEM results showed that surface of ZnO nano spheres is well covered with CdS. UV–visible spectrum showed the rise of a new optical band due to CdS deposition which effectively tuned the band gap of ZnO from 3.12 eV to 1.877 eV. XRD analysis revealed the successful formation of hexagonal phases of CdS and ZnO. The materials were applied as photoanodes in DSSCs with and without dye sensitization. P3HT (Poly (3-hexylthiophene) was used as a hole conducting polymer. CdS deposition and sensitization with different dyes showed a significant effect on the overall efficiency of fabricated devices. The ZnO/CdS based DSSC sensitized with carminic acid showed a current density (Jsc) of 8.72 mA/cm2 with an open circuit voltage (Voc) of 0.43 V and an overall efficiency of 1.42%. While the same photoanode material sensitized with pyrocatechol violet gave Jsc value of 9.13 mA/cm2 with a Voc of 0.39 V and an overall efficiency of 1.55%.

Flexible CdS and PbS nanoparticles sensitized TiO2 nanotube arrays lead to significantly enhanced photocatalytic performance

TiO2 nanotube arrays (TiO2 NTAs) were mainly synthesized by the anodization of Ti foils, and the Ti mesh anodization was little researched. TiO2 NTAs/Ti mesh showed remarkably high photocatalytic performance in pollutant treatment and photocurrent/hydrogen generation. In this paper, TiO2 NTAs were synthesized on flexible three dimensional Ti mesh surface, and CdS/PbS sensitizers covered TiO2 NTAs by the hydrothermal deposition. Especially, the S–CdS photocatalyst prepared by CdS sensitization showed strong photocurrent and photocatalytic pollutant removal capacity. RhB, MB dyes and Cr(VI) ions were effectively purified under solar irradiation, and samples also showed excellent visible light-driven photoelectric ability. Furthermore, the S–PbS photocatalyst prepared by PbS sensitization showed high photocatalytic water splitting performance. The functional material offers a flexible, low cost and high photocatalytic membrane for waste water treatment and photocurrent/hydrogen generation.

Fabrication of Nanosticks-Like CdS Sensitizer for the Application of Solar Cells.

The novelty of this work is to fabricate the Nanosticks (NSs) like CdS sensitizer on the surface of TiO₂ electrode by chemical bath deposition (CBD) method with a very high vacuum annealed at 350 °C for 30 min. Whereas, nanocrystalline TiO₂ electrodes have been prepared on FTO (SnO₂: F) glass by a spin-coating method with high purity (99.99%, Degussa P25) TiO₂ powder. The surface of the CdS layer has been covered by NSs like structures which are confirmed by the scanning electron microscope image. The 100 nm of platinum-coated FTO substrate and polysulfide-based electrolyte are used to assemble the Grätzel Solar cell (GSC). The performance of solar cell (SC) based on NSs like CdS has been compared with the nanoparticles (NPs) based CdS sensitized SC, where CdS NPs has synthesized by CBD without any post-annealing. The efficiency of NSs like CdS sensitized SC exhibits 2.44%, which is 2 folds of the efficiency of the CdS NPs sensitized SC. The NSs like CdS sensitized SC shows the highest photocurrent 20.24 mA/cm² compared to CdS NPs based SC.

CdS-sensitized chestnut-like TiO2-based thin films for improved photoelectrochemical performance

In this paper, novel chestnut-like TiO2 was successfully synthesized by the hydrothermal method. The presence of chestnut-like structure not only increased the density of active sites with a high accessibility, but also facilitated the diffusion of solvent and products. Then, the chestnut-like TiO2 based thin films on FTO were successfully prepared by the doctor-blade method. Moreover, the thickness of thin films can be adjusted via different repeated times. After that, in order to further improve its photoelectric properties, the adoption of CdS sensitization with different time interval via chemical bath route was studied. Photoelectrochemical (PEC) measurements showed that CdS/TiO2 photoelectrode under the optimal condition exhibited minimal resistance and the fastest charge transfer rate. The highest photocurrent density can reach 35.1[Formula: see text][Formula: see text]A[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text], which is almost 5-fold than that of pure chestnut-like TiO2 (7.6[Formula: see text][Formula: see text]A[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]) based thin films. The enhanced PEC properties could be ascribed to the improvement of light harvesting and the formation of heterostructure to accelerate the separation of photo-generated electron-hole pairs.

Hidden energy levels? Carrier transport ability of CdS/CdS1-xSex quantum dot solar cells impacted by Cd-Cd level formation.

In quantum dot sensitized solar cells (QDSSC), a cascade energy level structure controlled by assembly of cadmium-chalcogenide quantum dots can remarkably improve the sunlight harvesting and charge carrier lifetime. Despite the advantages of using co-sensitizers, energy conversion efficiencies are still low. An increased understanding of the causes of the low photoconversion efficiency (PCE) will contribute to the development of a straightforward approach to improve solar cell performance by exploiting co-sensitization. Herein we discuss how an excess of cadmium causes structural disorder and defect levels impacting the PCE of QDSSC devices. Thus, outer CdS1-xSex/inner CdS QD-co-sensitized B,N,F-co-doped-TiO2 nanotubes (BNF-TNT) were prepared. Chalcogenides were deposited by the SILAR method on BNF-TNT, varying the load of CdS as the inner sensitizer, while for CdS1-xSex, five SILAR cycles were used (5-CdS1-xSex), controlling the nominal S/Se molar ratio of the ternary alloy. Cd defects named as Cd-Cd energy levels were observed during CdS sensitization. Although incorporation of outer CdS1-xSex provides a tunable band gap to achieve good band alignment for carrier separation, Cd-Cd energy levels in the sensitizers act as recombination centers, limiting the overall electron flow at the BNF-TNT/CdS/CdS1-xSex interface. A maximum PCE of 2.58% was reached under standard AM 1.5G solar illumination at 100 mW cm-2. Additional limitations of SILAR as a deposition strategy of QDs are also found to influence the PCE of QDSSC.

Mutual effect of extrinsic defects and electronic carbon traps of M-TiO2 (M = V, Co, Ni) nanorod arrays on photoexcited charge extraction of CdS for superior photoelectrochemical activity of hydrogen production

Understanding the photoexcited charge carrier dynamics such as separation, transportation and extraction in smart hybrid nanocomposites is the key to high performance solar cells. Nanocomposites possess advantage of broader solar absorption with their fast photoexcited charge separation and transportation but their use as photocorrosion-stable material is yet to be explored. Also, bulk and surface defects in individual components of the nanocomposites boost the efficiency of the solar cells, despite of the fact the recombination of the photoexcited charges at the interfaces lead to a substantial loss of charges and realizing a big challenge. Herein, the extrinsic defects like bulk and surface defects are induced by transition metal (M = V, Co, Ni) doping of M − TiO2 nanorod arrays. Consequently, the hydrothermal synthesis method offers the tuning of the carbon trapping states depending upon the type of the metal doped in M − TiO2 that decelerates the charge carrier dynamics in the M-TiO2/CdS (M = V, Co, Ni) nanocomposites with the increase in the amount of carbon. Excellent charge extraction is observed in VTiO2 (4% carbon) from its CdS sensitizer with photocurrent density of 2.06 mA/cm2 than NiTiO2 (14.6% carbon), TiO2 (18.94% carbon) and CoTiO2 (39.2% carbon) with photocurrent densities of 1.83, 1.46 and 1.34 mA/cm2 at 0 V versus Ag/AgCl under 100 mW/cm2 light intensity, respectively. This shows primary dependence of photoexcited charge dynamics upon the density of the carbon trapping states to be least while secondary dependence upon the density of the extrinsic defects in M − TiO2 to be maximum. This work creates a paradigm for future studies to have a broader insight of the photocatalyst's overall functioning to boost the efficiencies in solar cells by controlling the amount of electronic carbon traps during the synthesis of a large class of inorganic semiconductor photocatalysts.

CdS sensitized pristine and Cd doped ZnO solar cells: Effect of SILAR cycles on optical properties and efficiency

We report the CdS sensitized pristine and Cd doped ZnO using a successive ionic layer adsorption and reaction (SILAR) technique towards solar cell application. The effect of number of CdS SILAR cycles on the performance of pristine and Cd doped ZnO solar cells have been studied. A chemical synthesis technique at relatively low temperature (70 °C) was employed for the preparation of nanoparticulate powders of ZnO and Cd: ZnO. Doctor blade technique was used towards the preparation of film. The sensitization of CdS was done over ZnO and Cd: ZnO films with different SILAR cycles (4–16). The UV–Vis clearly shows the significant change in absorbance with the number of SILAR cycles for both the films. The results of J-V measurements with polysulfide as electrolyte and CuS as counter electrode were obtained by using 2420 Keithley source meter. The maximum power conversion efficiency of 0.279% and 0.604% was obtained for 12 cycles CdS sensitized ZnO and Cd: ZnO based solar cells, respectively.

Dye-sensitized solar cell performance of a cobalt(III/II) redox mediator with the 4,5-diazafluoren-9-one ligand

The development of redox shuttles containing electrolytes is very important for obtaining efficient dye-sensitized solar cells (DSSCs). We have therefore synthesized and characterized homoleptic [Co(dafo)3]3+/2+ complexes (dafo = 4,5-diazafluoren-9-one) and studied the effect of the redox diffusion coefficient on the photovoltaic performance of their DSSCs. The compounds were characterized by FTIR, UV–Vis spectroscopy, NMR and MS spectroscopic data. The [Co(dafo)3]2+/3+ system has been used to formulate redox-mediator electrolytes for application in DSSC devices with the N719 ruthenium-polypyridyl dye, TiO2 and CdS sensitizer. This system shows a slightly higher power-conversion efficiency (η = 0.30%) in a DSSC device prepared with a CdS/Pt electrode. Although the [Co(dafo)3]3+/2+ electrolyte shows a moderately high open-circuit potential (Voc = 0.58), it suffers from a reduced short-circuit current (Jcs = 2.04). The data suggest a decreased turnover of the CoIII/II redox couple at the Pt counter electrode for the [Co(dafo)3]3+/2+ system, concomitant with an increased resistance to mass-transfer diffusion.

CdS sensitized cadmium doped ZnO solar cell: Fabrication and characterizations

Chemical solution deposition of the porous Cd doped ZnO films has been carried out on Indium Tin Oxide (ITO) coated glass substrate. Photosensitization of Cd doped ZnO photo electrode with nanocrystalline CdS is carried out using successive ionic layer adsorption reaction (SILAR) technique. The cadmium nitrate and sodium sulfide anhydrous were used as precursors for Cd2+ and S2−, respectively. The bare ZnO, Cd doped ZnO and CdS sensitized ZnO & Cd:ZnO films were characterized by using scanning electron microscopy, X-ray diffractometry and UV–Vis spectroscopy. The effect of Cd doping and sensitization of CdS on the performance of solar cell was studied by using current-voltage measurement. The enhancement in power conversion efficiency is observed for CdS/Cd:ZnO (0.43%) with that of CdS/ZnO (0.06%) photoanode.

Ultrasensitive photoelectrochemical immunosensor for insulin detection based on dual inhibition effect of CuS-SiO2 composite on CdS sensitized C-TiO2

Abstract High sensitivity of biosensor is one of the most important factor to realize the accurate detection of biomarkers. To achieve this purpose, enhancing initial signal and amplifying the value of signal change are two main approaches. In this study, a novel signal-off photoelectrochemical (PEC) immunosensor for highly sensitive determination of insulin was developed upon dual inhibition effect of CuS-SiO 2 composites toward CdS sensitized carbon doped titanium dioxide (C-TiO 2 /CdS). Due to the doping of carbon and sensitization of CdS, C-TiO 2 /CdS sensitized structure was employed as ideal photoactive matrix, which provided stable and enhanced basal signal. To achieve the amplification of signal change value, CuS-SiO 2 composites were prepared and used as labels. On account of the competitively light harvesting and electron donors consuming by p-type semiconductor CuS, less light energy and electron donors arrived at the C-TiO 2 /CdS sensitized structure. Besides, the remarkable steric hindrance effect of CuS-SiO 2 labeled secondary antibodies (CuS-SiO 2 -Ab 2 ) conjugates obstructed the transfer of electrons and diffusion of the electron donors to the photoelectrode surface, leading to further decrease of photocurrent compared with the pure CuS nanoparticles. Greatly enhanced sensitivity is achieved due to the dual inhibition effect of CuS-SiO 2 composites on C-TiO 2 /CdS. Taking advantage of the synergy effect of C-TiO 2 /CdS sensitized structure and dual inhibition effect of CuS-SiO 2 -Ab 2 bioconjugates, the as-prepared immunosensor for insulin exhibited high sensitivity and good stability with a low detection limit of 0.03 pg mL −1 . Additionally, the strategy provided an efficient and simple approach for signal amplification and held great promise for other PEC immunoassay development.

Improved Stability and Photoelectrochemical Performance of Al2O3 Passivated CdS/1D Zr:Fe2O3 Heterojunctions for Solar Hydrogen Generation

Al2O3 passivated CdS sensitized 1D Zr:Fe2O3 nanorod arrays have been synthesized on fluorine-doped tin oxide (FTO) by hydrothermal method and dip coating methods. The photoelectrochemical study of CdS/1D Zr:Fe2O3 photoelectrode exhibits the current density of 4.2 mA.cm-2 at 0 V (vs. Ag/AgCl) which is 2.8 time higher than the bare 1D Zr:Fe2O3. The reduced recombination and the effective transport of photogenerated holes in CdS facilitates the enhancement in photoelectrochemical performance. Furthermore, the photocurrent and stability of the CdS/Zr:Fe2O3 nanorods was significantly enhanced by Al2O3 compared to bare CdS/Zr:Fe2O3 heterojunction due to its ability to act as an effective hole transport as well as photocorrosion protecting layer. The chemical analyses and nanostructural study of the Al2O3 coated CdS/1D Zr:Fe2O3 photoelectrodes confirms the presence of Al2O3 on surface of CdS and 1D Zr:Fe2O3 nanorods embedded in the CdS flakes. These remarkable enhancements in light energy harvesting, improvement in charge transport and stability directly suggest the usefulness of photoelectrodes for solar hydrogen generation. KEYWORDS: Al2O3 passivation; Zr:Fe2O3 nanorod arrays; CdS Sensitizer; Hydrogen generation ACKNOWLEDGMENT This research was supported by the BK21 plus program, the Korean National Research Foundation (Nano-Material Fundamental Technology Development, 2016M3A7B4909370).

Optimization of the Photoanode of CdS Quantum Dot-Sensitized Solar Cells Using Light-Scattering TiO2 Hollow Spheres

CdS quantum dot-sensitized solar cells (QDSCs) have been fabricated and their photoanode optimized by altering the thickness of the photoelectrode and CdS deposition conditions and applying a ZnS electron-blocking layer and TiO2 hollow spheres. Hydrothermally grown TiO2 nanocrystals (NCs) with dominant size of 20 nm were deposited as a sublayer in the photoanode with thickness in the range from 5 μm to 10 μm using a successive ionic layer adsorption and reaction (SILAR) method. The number of deposition cycles was altered over a wide range to obtain optimized sensitization. Photoanode thickness and number of CdS sensitization cycles around the optimum values were selected and used for ZnS deposition. ZnS overlayers were also deposited on the surface of the photoanodes using different numbers of cycles of the SILAR process. The best QDSC with the optimized photoelectrode demonstrated a 153% increase in efficiency compared with a similar cell with ZnS-free photoanode. Such bilayer photoelectrodes were also fabricated with different thicknesses of TiO2 sublayers and one overlayer of TiO2 hollow spheres (HSs) with external diameter of 500 nm fabricated by liquid-phase deposition with carbon spheres as template. The optimization was performed by changing the photoanode thickness using a wide range of CdS sensitizing cycles. The maximum energy conversion efficiency was increased by about 77% compared with a similar cell with HS-free photoelectrode. The reason was considered to be the longer path length of the incident light inside the photoanode and greater light absorption. A ZnS blocking layer was overcoated on the surface of the bilayer photoanode with optimized thickness. The number of CdS sensitization cycles was also changed around the optimized value to obtain the best QDSC performance. The number of ZnS deposition cycles was also altered in a wide range for optimization of the photovoltaic performance. It was shown that the maximum efficiency was increased by about 55% compared with a similar QDSC with ZnS-free bilayer photoanode. The final improvement was carried out by applying methanol-based Cd precursor solution in the SILAR deposition process. The best photoanodes from the previous stages were selected and used in this sensitizing process. Besides, nanocrystalline TiO2 sublayers with different thicknesses were applied for further optimization. The results revealed that maximum power conversion efficiency of 3.7% was achieved as a result of such improvement, for a QDSC with optimized double-layer photoanode including TiO2 HSs and NCs and ZnS blocking layer.

Photoelectrochemical immunodiagnosis of canine leishmaniasis using cadmium-sulfide-sensitized zinc oxide modified with synthetic peptides

A photoelectrochemical immunosensor for the detection of anti-Leishmania infantum antibodies based on zinc oxide and cadmium sulfide films electrodeposited on an ITO-coated glass slide (CdS/ZnO/ITO) has been proposed. The effects of light/dark conditions and the kinetics of CdS sensitizer regeneration were evaluated by scanning electrochemical microscopy in feedback mode. The platform was modified using two different peptides (PEP 13 and PEP 16) from two different proteins of high specificity and selectivity toward recognition of L. infantum antibodies, producing Peps/CdS/ZnO/ITO. This photoelectrochemical immunosensor provides a cheap and promising method of discriminating between positive and negative canine serum samples.

Improved Stability and Photoelectrochemical Performance of Cds/1D Zr:Fe2O3 Nanorod Arrays with Al2O3 Passivation Layer for Hydrogen Generation

CdS sensitized 1D Zr:Fe2O3 nanorod arrays have been synthesized on fluorine-doped tin oxide (FTO) by hydrothermal method. The photoelectrochemical measurement results of CdS/1D Zr:Fe2O3 photoelectrode shows the current density of 4.2 mA.cm-2 at 0 V (vs. Ag/AgCl) which is 2.8 time higher than the bare 1D Zr:Fe2O3. The reduced recombination, and the effective transport of photogenerated holes in CdS facilitates the enhancement in photoelectrochemical performance. Furthermore, the photocurrent and stability of the CdS/Zr:Fe2O3 nanorods was significantly enhanced by Al2O3 layer as compared to bare CdS/Zr:Fe2O3 heterojunction due to its ability to act as an effective hole transport as well as passivation layer. The chemical analyses and nanostructural study of the Al2O3 coated CdS/1D Zr:Fe2O3 photoelectrodes confirms the presence of Al2O3 on surface of CdS and 1D Zr:Fe2O3 nanorods embedded in the CdS flakes. These remarkable enhancements in light energy harvesting, improvement in charge transport and stability directly suggest the usefulness of photoelectrodes for solar hydrogen generation. KEYWORDS: Zr:Fe2O3 nanorod arrays, CdS Sensitizer, Al2O3 passivation layer, Hydrogen generation ACKNOWLEDGMENT: This research was supported by the BK21 plus program, the Korean National Research Foundation (Nano-Material Fundamental Technology Development, 2016M3A7B4909370).