Photosensitive Electrode Research Articles

Ferrocene Based Metal-Organic Framework-Carbon Nanotubes Composite in a Zn-Ion Battery Charged By a Novel Perovskite Solar Cell

A non-aqueous Zinc-ion battery is fabricated in air with a distinctive configuration comprising CoFe-ferrocene dicarboxylic acid (FcDA) metal organic framework/carbon nanotubes (CNTs) composite acting as cathode and the counter electrode being Zn powder (Zn PW)/coffee activated carbon (Zn/Cl-AC). A perovskite (PSK) solar cell is used to charge ZIB. The PSK solar cell is characterized by a n-i-p based architecture, wherein the Cs0.1Fa0.9PbI3 perovskite (PSK) acts as the photo-sensitive electrode and carbon paste as the hole transport layer. The PSK was modified with tetra-butyl ammonium perchlorate (TBAP) to passivate defects via electrostatic interactions and hydrogen bonding. Further the butyl chains provided moisture resistance due to their hydrophobic nature. CoFe-FcDA/CNTs//Zn PW/Zn/Cl-AC battery when electrically charged upto 1.8 V delivers a discharge capacity of 250 mAh/g at 40 mA/g current density. When the cell is photo-charged to 1.5 V in the absence of any bias it delivers a discharge capacity of 164 mAh/g at the same current density. The ZIBs gets rapidly photo-charged in just ~5.6 mins making this a standalone solar powering unit for portable electronic devices. Solar charged battery is first of its kind which can sustain photo-charging and dark discharge at 300 mA/g current density with retention of ~82% and the overall solar conversion efficiency declines from 7.6% to 6.3%. The results indicate the cyclability of the integrated system and stability of PSK-TBAP solar cell. Figure 1

Solar-driven induced photoelectron remember effect involved in core–shell NiCo2S4@Ni3V2O8 composite electrode with superior electrochemical energy storage for asymmetric supercapacitor

Photo-assisted supercapacitor systems offer a compelling approach to effectively harnessing both solar and electrical energy. In this study, the core–shell heterostructure NiCo2S4@Ni3V2O8 (NCS@NVO) was successfully synthesized for the development of photosensitive supercapacitor electrodes. NCS@NVO demonstrated a pronounced photoelectron memory effect under illumination, attributed to the solar-driven contributions of both NCS and NVO, as photon absorption facilitated electron-hole pair separation and transport. Compared to the specific capacitance in the dark (2292F g−1 at 1 A g−1), the capacitance of the NCS@NVO composite electrode increased dramatically to 3025F g−1 when exposed to light. Moreover, the capacitance retention rate remained remarkably high at 99.83 % after 10,000 cycles at 20 A g−1. In addition, the NCS@NVO hybrid supercapacitor achieved an outstanding energy density of 63.56 W h kg−1 under illumination, alongside a power density of 789.84 W kg−1. This study thoroughly investigated the solar-induced photoelectron memory effect in the NCS@NVO composite electrode for asymmetric supercapacitors, paving the way for the design of high-performance photosensitive nano-electrodes in advanced electrochemical energy storage applications.

Flexible and Dynamic Light-Guided Electrochemiluminescence for Spatiotemporal Imaging of Photoelectrochemical Processes on Hematite.

Here, we report an electrochemiluminescence (ECL)-based approach for imaging of local photoelectrochemical processes on hematite in a spatially and temporally controlled manner. The local processes were guided by flexible and dynamic light illumination, not requiring any prepatterned conductive features or photomasks, with a digital micromirror device (DMD). The imaging approach was based on light-addressable electrochemical reactions on hematite, resulting in photoinduced ECL emission for spatiotemporally resolved imaging of photoelectrochemical processes selectively guided by light illumination. After clarifying the capability of hematite as a photosensitive electrode, we validated that the illuminated hematite exhibited stable light-guided ECL emission in correspondence with the illuminated area, with a spatial resolution of 0.8 μm and a temporal resolution of 1 μs, even over a long period of 6 h. More importantly, this study exemplified the simple yet effective ECL-based approach for electrochemical visualization of local photoelectrochemical processes guided by flexible and dynamic adjustment of light illumination in a spatiotemporally controlled way.

Heterogeneous Structures Consisting of Rod-like ZnO Interspersed with Ce2S3 Nanoparticles for Photo-Sensitive Supercapacitors with Enhanced Capacitive Performance.

Photosensitive supercapacitors incorporate light-sensitive materials on capacitive electrodes, enabling solar energy conversion and storage in one device. In this study, heterogeneous structures of rod-shaped ZnO decorated with Ce2S3 nanoparticles on nickel foam (ZnO@Ce2S3/NF) are synthesized using a two-step hydrothermal method as photosensitive supercapacitor electrodes for capacitance enhancement under visible light. The formation of ZnO@Ce2S3 heterogeneous structures is confirmed using various structural characterization techniques. The area-specific capacitance of the ZnO@Ce2S3/NF composite electrode increased from 1738.1 to 1844.0mFcm-2 after illumination under a current density of 5 mAcm-2, which is 2.4 and 2.8 times higher than that of ZnO and Ce2S3 electrodes under similar conditions, respectively, indicating the remarkable light-induced capacitance enhancement performance. The ZnO@Ce2S3/NF electrode also exhibits a higher photocurrent and photovoltage than the two single electrodes, demonstrating its excellent photosensitivity. The improved capacitance performance and photosensitivity under illumination are attributed to the well-constructed energy-level structure, which stimulates the flow of photogenerated electrons from the outer circuit and the involvement of photogenerated holes in the resulting surface-controlled capacitance. In addition, the assembled ZnO@Ce2S3/NF-based hybrid supercapacitor exhibits a great energy density of 145.0 mWhcm-2 under illumination. This study provides a novel strategy for the development of high-performance solar energy conversion/storage devices.

Cobalt-doped β-Ni(OH)2 electrode fabricated by in-situ chemical corrosion for photo-assisted supercapacitor with low-temperature operation

The integration of photosensitive electrode materials with excellent electron and ion transfer dynamics provides an effective strategy to address the unsatisfactory low temperature tolerance of energy storage devices. Here, the surface morphology reconstruction derived from the in-situ chemical corrosion of nickel foam (NF) endow the Co-doped β-Ni(OH)2 electrode material excellent electrolyte contact and more exposed active surface, showing the super area specific capacity under illumination (15.01 F/cm2 at 60 mA/cm2), which is three times higher than that without illumination (5.29 F/cm2 at 60 mA/cm2) at room temperature. The energy density of the assembled asymmetric photoassisted supercapacitor (ASC) reaches 1.85 mWh/cm2 at a power density of 36.01 mW/cm2 under illumination, increased by 94.7 % compared to that without illumination at room temperature. Benefiting from the excellent photoelectric and photothermal conversion ability of the electrodes, the energy density of ASC can reach up to 0.63 mWh/cm2 with a power density of 34.94 mW/cm2 under illumination even at a low temperature of −40 °C, demonstrating the potential application of the wide temperature range of the supercapacitor.

Photo-sensitive electrodes based on NiO: SnO2 Nano-composites prepared by chemical method

In the beginning, NiO/SnO2 nanocomposite thin film was prepared of nickel nitrate (1.5213) gm that was weighed and dissolved in distilled water to obtain a specific molar concentration at room temperature and prepared as nanoparticles and mixed with half mount (0.5121) gm of SnO2, in addition to other steps to obtain on the nanocomposite to study some features it. The structural properties of nanocomposite thin films using the chemical technique studied, such as XRD, FE-SEM, and AFM, were found that NiO/SnO2 Nano-composite crystallizes are hexagonal structures with an average crystallite size of 16.30nm. also, the FE-SEM images study the morphology of the NiO: SnO2 thin films, it catches sight of the nanostructure thin films of the NiO: SnO2 Clearly, the surface roughness of nanocomposite according to AFM noted that gets better as a result of the radical’s mobility. The FT-IR spectrum of the synthesized composite has been studied. UV-Spectral absorption of NiO: SnO2 where peak range of wavelength (225-550) nm and notice an increase in the absorption range towards the red wavelength after adding nickel oxide, and use the prepared sample in applied as photosensitive electrodes, voltage characteristics of chemical synthesized: SnO2 nanoparticles shows the current vs voltage plot of chemical-synthesized NiO: SnO2 nanoparticles coated onto glass substrates using dip coating method where add SnO2 due to increasing the conductivity of the nanocomposite.

Photoelectrochemical sensor based on the sensitive interface of photosensitive electrode for the detection of hydrogen peroxide in dried bean curds

A novel photoelectrochemical (PEC) sensor based on the sensitive interface of photosensitive electrode has been developed for the enzyme-free PEC response of hydrogen peroxide (H2O2). Polythionine (PTh) was polymerized on tin dioxide nanoparticles (SnO2 NPs) modified Indium Tin Oxide (ITO) electrode by scanning voltammetry. Characterization by scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet–visible spectroscopy showed that PTh was successfully polymerized on the surface of the photosensitive electrode and did not change the structure of SnO2 NPs. The PTh modified SnO2 NPs photosensitive electrode has excellent photoelectric performance, further enhancing the photocurrent response of H2O2. The calibration curve was linear in the range of 0.03–8 mM with a detection limit of 0.003 mM. The PEC sensor was successfully applied to detect H2O2 residues in dried bean curds. The results showed no remarkable difference compared with the reference iodometry method, suggesting that this alternative method can be used for the quality control analysis of dried bean curds.

MoS2 nanosheets on Cu-foil for rapid electrocatalytic hydrogen evolution reaction

• MoS 2 nanosheets were deposited on Cu-electrode for hydrogen evolution reaction. • Electrodes shows low over potential of −70 mV in illuminating condition. • Electrode shows the stability upto 40 h at current of −10 mA/cm 2 . • Charge transfer resistance of as low as 2.1 Ω cm 2 is achieved. Herein, we demonstrate the MoS 2 /Cu electrodes for photosensitive electrocatalytic hydrogen evolution reaction (HER). Liquid phase exfoliated MoS 2 nanosheets have been deposited Cu foil by electrophoresis technique for preparation of photosensitive and large area electrodes. Electrodes have shown rapid electrocatalytic HER activity with low over potential of −110 mV in dark and −70 mV vs RHE in illuminating condition. Charge transfer resistance of as low as 4.2 Ω cm 2 is realised which is further reduced to 2.1 Ω cm 2 on light illumination owing to injection of photogenerated electrons. Photosensitive behaviour of MoS 2 nanosheets and MoS 2 /Cu Schottky interface leads to the enhanced rate of electrocatalytic reaction. MoS 2 /Cu electrode has shown stability upto 40 h. Present finding encourages the production of clean energy through HER activity speeding up by illumination visible Sun light.

Electrophoretic deposition of MoS2 nanosheets for photoelectrochemical type photodetector

Herein, we demonstrate the electrophoretic deposition of MoS2 nanosheets on ITO coated glass substrate for preparation of working electrode for photoelectrochemical type photodetector. Vertical alignment of MoS2 nanosheets on substrate offers high surface-to-volume ratio, enhancing the electrochemical charge transport. MoS2 nanosheets based working electrodes shows obvious photovoltaic effect with photocurrent of 0.5 μA/cm2 at zero bias under 670 nm light of power intensity 100 mW/cm2. Maximum photoresponsivity of 170 μA/W, IPCE of 3 × 10−2% is realised owing optimized conditions. Overall, present finding advocates the development of large area, transparent and photosensitive electrode for PEC type photodetection application for visible light.

An Optically Addressed Nanowire-Based Retinal Prosthesis With Wireless Stimulation Waveform Control and Charge Telemetering

Current retinal prostheses (RPs) have not achieved useful vision restoration, as their resolution is limited by power dissipation and complexity of interconnect. This article presents an inductively powered wireless system on a chip (SoC) for an electrically controlled, optically addressed retinal prosthetic system. The SoC interfaces to a co-fabricated nanoengineered photosensitive electrode array using only two wires. To reduce the thermal dissipation near sensitive retinal tissue, the proposed design pushes voltage regulation and charge-balanced stimulation control off the implant via a duty-cycled wireless charge metering technique. A calibration technique compensating for power fluctuation caused by eye movement is also presented. Implemented in 180-nm CMOS and delivering up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3~\mu \text{C}$ </tex-math></inline-formula> of charge at 20-nC resolution, the SoC achieves 73% RF-to-stimulation power efficiency.

Paper-Based Flexible and Photosensitive Electrodes for Electrochemical Hydrogen Evolution

We report the fabrication of a flexible and photosensitive electrode for electrocatalysis using efficient, robust, and photosensitive two-dimensional molybdenum disulfide (2D-MoS2) nanosheets and f...

Calixarene-Protected Titanium-Oxo Clusters and Their Photocurrent Responses and Photocatalytic Performances.

Three photosensitive tert-butylcalix[n]arene (TBC[n], n = 4, 6, 8)-protected titanium-oxo clusters (TOCs), formulated as [Ti4(μ3-O)2(TBC[4])2(OiPr)4(DEF)2]·DEF (1, TBC[4]-Ti4, DEF = N,N-diethylformamide), [Ti4(μ4-O)TBC[6](OCH3)9]·H2O (2, TBC[6]-Ti4), and [Ti4(μ3-O)2(OiPr)4TBC[8](DEF)2]·DEF (3, TBC[8]-Ti4), were successfully synthesized and characterized. Because of the generation of charge transfer from TBC[n] to the TiO core, the three TBC[n]-decorated TOCs show a broadened visible-light absorption and narrowed optical band gap based on the UV-visible spectra and density functional theory calculations. The corresponding photosensitive electrodes prepared using these three TOCs exhibit stable photocurrent responses. Furthermore, their photocatalytic performances for hydrogen evolution and methylene blue degradation were evaluated, and all of the materials display excellent photocatalytic activity and stability. The calixarene-Ti coordination is therefore an effective strategy to enlarge the visible-light absorption band of Ti-O materials and improve their photoelectric/photocatalytic performances.

Measuring the Electrical and Photonic Properties of Cobalt Oxide-Containing Composite Carbon Fibers

In this work, cobalt acetate was incorporated into polyacrylonitrile (PAN) polymer through electrospinning as the cobalt oxide source. After oxidization and pyrolysis, a PAN-derived composite carbon fiber containing cobalt oxide was obtained. Measuring the electrical and photonic properties of the composite fiber under visible light irradiation was performed to evaluate the photoelectric behavior of the composite fiber. The p-type semiconducting behavior of the composite fiber was confirmed by measuring the open circuit voltage of a photochemical fuel cell consisting of the photosensitive electrode made from the composite fiber. The application of the composite fiber for glucose sensing was demonstrated.

Etching reaction-based photoelectrochemical immunoassay of aflatoxin B1 in foodstuff using cobalt oxyhydroxide nanosheets-coating cadmium sulfide nanoparticles as the signal tags

A new split-type photoelectrochemical (PEC) immunosensing platform was designed for sensitive detection of aflatoxin B1 (AFB1) in foodstuffs, coupling with enzymatic hydrolysate-triggered etching reaction of cobalt oxyhydroxide (CoOOH) on cadmium sulfide (CdS) nanoparticles-functionalized interface. Initially, the photosensitive electrode was prepared by coating CoOOH nanosheets on the surface of CdS nanoparticles to quench the photocurrent. Thereafter, a competitive-type enzyme immunoreaction was carried out on monoclonal anti-AFB1 antibody-conjugated magnetic bead by using alkaline phosphatase (ALP)-labeled bovine serum albumin-AFB1 (AFB1-BSA) conjugate as the competitor. With the formation of immunocomplex, the carried ALP hydrolyzed ascorbic acid 2-phosphate (AAP) into ascorbic acid (AA) and phosphate. The former ascorbic acid produced etched or dissolved CoOOH nanosheets into Co2+ ions, thus resulting in the exposure of CdS nanoparticles on the surface to enhance the photocurrent of the modified electrode. Under optimum conditions, the photocurrent decreased linearly with the increasing AFB1 concentration in the dynamic range of 0.01–10 ng mL−1, and the limit of detection was 2.6 pg mL−1. The precision of this method (expressed as RSD) was ±8.6%. In addition, the accuracy was monitored by analyzing spiked food samples, and gave the well-matched results with the referenced ELISA method.

Comparative study of noise in low-current Townsend discharge in nitrogen and argon.

Noise in a low-current Townsend discharge in argon and nitrogen is studied. Experiments were performed in a "semiconductor-gas-discharge" structure constituted by a short plane-parallel discharge gap and a high-resistivity photosensitive semiconductor electrode. The noise of optical emission from gas excited by the discharge was investigated with a photomultiplier. Experiments were done at the room temperature of the discharge structure. According to the obtained data, the noise of discharge glow in Ar is astonishingly low-similar to that earlier found for the cryogenic discharge in this gas. At equal time-average photon fluxes emitted by discharges in both gases, the noise of gas glow in nitrogen substantially exceeds the corresponding value for argon. A statistical processing of signals of glow brightness for the two gases revealed the origin of this difference: While the power spectral density of noise in nitrogen is specified by a band of frequencies with the increased density, in argon it is nearly constant in an extended frequency range. At the same time, intensity of noise is practically the same for both gases in the ranges of low and high frequencies. The relationship of the increased noise in nitrogen with a low critical current density for oscillatory instability of the Townsend discharge in this gas is considered.

Photo Electrochemical Responses of Titanium Oxide Nanotube Arrays on Pure Titanium Substrate

This paper deals with photo electrochemical responses of titanium dioxide nanotubes on pure titanium. Photosensitive electrodes (anodes) with the major composition of doped oxides were made using the titanium oxide nanotubes. The responses of the oxide nanotubes with different additives to both ultraviolet (Uv) and visible (Vis) light were illustrated. Research results of the enhance absorption of visible light by adding transition metals or metallic oxides including Co, Ni, Cu, Zn, CoO, CuO, NiO, ZnO into the nanotubes will be shown. Finally, test results of the photo electrochemical fuel cells using diluted glycerol as the fuel under the irradiation of natural light will be presented and the open circuit voltage values will be given. The photo electrochemical test results show that the doped titanium oxide nanotubes show the n-type behavior. The photo anodes can absorb both ultraviolet and visible light. But the response to the ultraviolet light is five to ten times stronger.

Development of an optically modulated piezoelectric sensor/actuator based on titanium oxide phthalocyanine thin film

A photosensitive electrode made of titanium oxide phthalocyanine (TiOPc) was modulated optically and integrated with a piezoelectric sensor/actuator which allowed us to obtain in situ tailoring of real-time spatial performance. The TiOPc thin film was formed using a spin-coating process. The experimental results showed that the impedance of the TiOPc thin film irradiated by visible light was 0.053 times that of the film not irradiated by visible light. With the successful tailoring of the impedance of the photosensitive electrode, we designed an optically modulated lead zirconate titanate (PZT) sensor/actuator and tested it for different applications. The influence of the impedance match between the TiOPc thin film and PZT of our various optically modulated PZT sensor/actuator designs is discussed in detail. The optically modulated PZT sensor was designed for one-dimensional mode 1 sensor applications. In addition, the successful implementation of the DC effect allowed us to control the mode shape using our optically modulated PZT actuator which was tailored in real time in situ with different optical images. Potential applications of this newly developed TiOPc thin film sensor/actuator include deformable mirrors, microfluidic control applications, and vibration sensing/actuating.

Fabrication and Studies on FTO/(Compact ZnO/Porous ZnO: Eosin-Y)/C: FTO Solar Cell

ABSTRACT Dye sensitized solar cells (DSSC) are photoelectrochemical solar cells. They are based upon an iodide tri-iodide redox couple mediated between a photosensitive electrodes of semiconductor materials stained with a photosensitive dye and a catalytic counter electrode. In the present investigation, ZnO compact layer was deposited using chemical solution deposition (CSD) method followed by porous ZnO layer by doctor blade (DB) method. Eosin-Y dye was used to sensitize ZnO films. DSSC fabricated using ZnO nanostructures with both, compact and porous layers (FTO/(Compact ZnO/Porous ZnO: Eosin-Y)/C/FTO), exhibited a conversion efficiency of ∼ 1.20% under 100 mW/cm2.

Fabrication of Customized Bio-Electrode for Neural Stimulation Using Rapid Prototyping Technique

In the treatment of disorders, bio-electrodes are used to be implanted into the patients’ deep brain for long-term stimulation. This paper presents a custom design and flexible fabrication process of bio-electrode for treating neural disorders using rapid prototyping (RP) technique. A 3D model of the bio-electrode is designed and the photosensitive resin electrode prototype is fabricated on the laser rapid prototyping machine, and then the bio-electrode is fabricated using this electrode prototype and the silicon rubber mold and winding technique. The spatial distribution of the electric field fabricated of the bio-electrode is analyzed, and the optical photomicrograph reveals that the cylindrical surfaces of the polyurethane of the bio-electrode have smooth surface and no visible microcracks, and the spiral lines are arranged densely and have no defects of loose and falling and partly protruding. The electrochemical experiments show that the electrochemical process of the bio-electrode is reversible and the bio-electrode has good functionality and stability property.

Photosensitization of TiO2 Nanostructures with CdS Quantum Dots: Particulate versus Tubular Support Architectures

AbstractTiO2 nanotube arrays and particulate films are modified with CdS quantum dots with an aim to tune the response of the photoelectrochemical cell in the visible region. The method of successive ionic layer adsorption and reaction facilitates size control of CdS quantum dots. These CdS nanocrystals, upon excitation with visible light, inject electrons into the TiO2 nanotubes and particles and thus enable their use as photosensitive electrodes. Maximum incident photon to charge carrier efficiency (IPCE) values of 55% and 26% are observed for CdS sensitized TiO2 nanotube and nanoparticulate architectures respectively. The nearly doubling of IPCE observed with the TiO2 nanotube architecture is attributed to the increased efficiency of charge separation and transport of electrons.