- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Photovoltaic Properties of an rGO/Pt Counter Electrode with AZO Photoanode for Dye-sensitized Solar Cells under Low Light Intensity
摘要： This study used reduced graphene oxide (rGO) applied to a platinum (Pt) counter electrode to improve light conversion efficiency. The study also used an Al-doped Zinc Oxide (AZO) nanosheet / TiO2 photoanode for the dye-sensitized solar cell (DSSC). Photovoltaic characteristics, electrochemical impedance spectroscopy (EIS), field-emission scanning electron microscopy (FE-SEM) and Raman spectroscopy were used to analyze DSSC. The different light intensities and photovoltaic characteristics were analyzed to determine optimal light intensity conditions. The unmodified Pt counter electrode was compared with the rGO/Pt counter electrode, photovoltaic conversion efficiency (η) increased from 3.60% to 4.04% due to the rGO modification as it possesses a higher specific surface area. Its low cost also makes it suitable for mass production. In addition, an AZO nanosheet / TiO2 photoanode was fabricated to form a double-layer structure in which photovoltaic conversion efficiency was 4.47 %. Finally, a DSSC with an AZO / TiO2 photoanode and rGO/Pt counter electrode was fabricated and had an photovoltaic conversion efficiency of 5.05 %. This study also analyzed the photovoltaic parameters of DSSC under different intensities, which shows the optimal photovoltaic conversion efficiency of 5.54% under 30mW / cm2.
关键词： photovoltaic conversion efficiency,low light intensity,Al-doped Zinc Oxide (AZO),hydrothermal synthesis,Dye-sensitized solar cell (DSSC),reduced graphene oxide (rGO)
更新于2025-09-12 10:27:22
-
Highly porous self-assembly of nitrogen-doped graphene quantum dots over reduced graphene sheets for photo-electrocatalytic electrode
摘要： Nitrogen-doped graphene quantum dots (NGQDs) are a diverse organic catalyst, competitive with other metallic catalysts due to their low cost, high stability, biocompatibility, and eco-friendliness. Highly functional multi-edge surfaces of NGQDs play a key role in imparting superb photocatalytic and electrocatalytic activity. However, when coating NGQDs by conventional techniques, such surfaces are not exposed for catalysis, due to the unwanted overlap of NGQDs sheets. To avoid this issue, here we propose a facile technique to orient NGQDs in a three-dimensional (3D) self-assembled foam-like structure, over reduced graphene oxide coated woven carbon fabric. This 3D assembled structure provides highly exposed active surfaces, which are readily available for catalytic reactions: however, in the conventional uniformly coated NGQDs layer, catalytic activity was limited by complex diffusion. The superb catalytic activity of the assembled NGQDs was utilized for the degradation of organic pollutant (methylene blue dye) from water. Additionally, the proposed electrode revealed much higher electrocatalytic activity than the rare Pt catalyst, owing to the easy diffusion of electrolyte and fast quenching of charges through the porous structure. The assembled NGQDs showed 50% higher photocatalytic degradation compared to uniformly coated NGQDs, which was further accelerated (50%) by application of the biased potential of 2 V; i.e. photo-electrocatalysis. The novel photo-electrocatalytic electrode offers high conductivity, stability, and flexibility, which make this complete carbon electrode highly attractive for other catalytic applications such as fuel cells, supercapacitors, and water splitting.
关键词： Reduced graphene oxide,Photo-electrocatalysis,Stable electrode,Three-dimensional self-assembly,Nitrogen-doped graphene quantum dots
更新于2025-09-12 10:27:22
-
The synthesis of carbon-based nanomaterials by pulsed laser ablation in water
摘要： Pulsed Laser Ablation in liquid (PLAL) is considered as a robust and simple technique for producing nanoparticles (NPs) using lasers. The carbon-based nanoparticles were fabricated via the PLAL approach by irradiating a graphite target with a pulsed Nd:YAG laser of wavelength 532 nm. The graphite target was immersed in distilled water and irradiated for 10 min. The pulse length, reputation rate, and ?uence were 6 ns, 10 Hz, and 0.4 J cm?2, respectively. The structural and physical properties of the synthesized NPs were investigated and analyzed using different characterization methods. For example, Transmission Electron Microscopy (TEM) images revealed diverse carbon nanostructures such as graphene nanosheets, nanospheres, nanospheres in the shape of a necklace, and nanotubes. The spectrum of Energy Dispersive X-Ray spectroscopy (EDX) con?rmed successful synthesis of high purity carbon nanostructures. Moreover, the result of X-Ray Diffraction (XRD) Spectroscopy indicated the presence of reduced Graphene Oxide (rGO) with a (002) plane and the absence of Graphene Oxide (GO). The transmission spectrum from Ultraviolet-Visible (UV–vis) analysis showed a strong trough at 266 nm which is attributed to the presence of carbon nanostructures. Furthermore, Fourier-Transform Infrared Spectroscopy (FTIR) analysis demonstrated the vibration bonds related to carbon. The nanostructures produced were semi-stable with little agglomeration as was inferred from the results of the Zeta Potential. Finally, the Dynamic Light Scattering (DLS) analysis supported the TEM results. PLAL technique is proved to be a simple method for producing carbon-based nanomaterials. Moreover, the laser ?uence was found to be an important factor which affects greatly the type of nanostructures that could be synthesized during laser ablation.
关键词： reduced graphene oxide,graphene,carbon-based nanomaterials,pulsed laser ablation
更新于2025-09-12 10:27:22
-
Morphologically modulated laser-patterned reduced graphene oxide strain sensors for human fatigue recognition
摘要： Laser heating provides an effective method to produce thermally reduced graphene oxide (rGO), it can also pattern the designed layout on the surface of graphene oxide (GO) during the reduction process. In this work, we demonstrated a flexible strain sensor based on the morphologically modulated laser-patterned reduced graphene oxide (LPG) film with a one-step process. Compared with the strain sensor using flat patterned rGO (0-1.2%) and curved-grid patterned rGO (CGPG) (0-4.1%), the strain sensor based on rectangular-grid patterned rGO (RGPG) have highest gauge factor (GF), up to 133 under 2.7% of physical deformation. Meanwhile, the RGPG strain sensors exhibit extraordinary linearity in a relatively large range of deformation (0-2.7%) and excellent endurance for over 1000 stretching-releasing circles. The RGPG strain sensor was used to monitor human fatigue. By analyzing eye blinking frequency and duration, it is possible to evaluate the fatigue level. We anticipate that the RGPG based strain sensor, prepared via a relatively simple and cost-effective process, may open up a broad spectrum of practical applications, such as driver fatigue evaluation and smart monitoring of human body movements.
关键词： wearable electronics,laser patterning,fatigue evaluation,flexible strain sensor,reduced graphene oxide
更新于2025-09-12 10:27:22
-
All-optical modulator based on reduced graphene oxide coated D-shaped fiber waveguide
摘要： An all-optical modulator of reduced graphene oxide coated D-shaped fiber structure, utilizing a convenient and controllable evanescent-field-induced deposition method, was designed in this study. By using the pump pulse at 980 nm, the signal light at 1550 nm was modulated with the rate of 50 kHz, and the maximum modulation depth of 8 dB was obtained using this device. Furthermore, this kind of modulator features strong mechanical stability, ease of fabrication, low cost and compatibility with optical fiber systems, which implies great potential in photonics applications such as all-optical switching and all-optical communication.
关键词： D-shaped fiber,photonics applications,all-optical modulator,evanescent-field-induced deposition,reduced graphene oxide
更新于2025-09-12 10:27:22
-
Laser-scribed reduced graphene oxide as counter electrode for dye-sensitized solar cell
摘要： Reduced graphene oxide (rGO) has been attracted considerable attention in the field of dye sensitized solar cells (DSSCs) to serve as a low cost and earth-abundant alternative to the conventional platinum-based counter electrodes. Recently direct laser writing technologies are emerging as an inexpensive, time-efficient and high-resolution method to produce catalytic rGO-based electrodes. Herein, we experimentally demonstrate that the laser-scribed rGO on ITO/PEN substrate was produced by a commercial LightScribe DVD burner and used as counter electrode for DSSC. SEM and Raman spectroscopy characterizations reveal that after laser-scribing rGO film presents a roughness structure with multi-layer curled or tilting graphenes. The cyclic voltammetry (CV) and electrochemical impedance spectrum (EIS) analyses were also conducted to explore its electrocatalytic activity and charge-transfer properties. Finally, the DSSC based on rGO counter electrode achieved a power conversion efficiency of 2.07% under one sun AM 1.5 G illumination. This work developed a simple and promising laser-scribing method to prepare rGO-based counter electrode materials for DSSCs applications.
关键词： dye-sensitized solar cell,laser-scribing,Reduced graphene oxide,counter electrode
更新于2025-09-12 10:27:22
-
Structural and optical study of CZTS-reduced graphene oxide composite towards photovoltaic device application
摘要： The deficit in obtaining targeted photo conversion efficiency for (Cu2ZnSnS4) CZTS based photovoltaic cell results either from insufficient photo charge carrier generation or e-/h+ pair transportation towards the end of electrodes, which lowers the device Voc and Jsc. On this regard, semiconducting absorber material merged with highly mobile reduced graphene oxide (rGO) as filler form a bridging network within active layer facilitates both improvement in charge carrier separation as well as transportation to electrodes before recombination occurs. A simple solution casting approach for CZTS nanoparticle anchored rGO composite for photovoltaic device application is reported here. The presence and distribution of CZTS nanoparticles over the surface of rGO sheet is confirmed from XRD, Raman, SEM and UV-Visible analysis.
关键词： Raman,XRD,Cu2ZnSnS4 (CZTS),reduced graphene oxide (rGO),SEM,Photovoltaic device
更新于2025-09-12 10:27:22
-
High photoresponse and fast carrier mobility: Two‐dimensional rGO‐AgBr/Ag composite based on Z‐scheme heterointerface with plasma for hydrogen evolution
摘要： With the improvement of people's living standard, energy shortage is increasingly severe. Photocatalysis technology is one of the most effective means to solve this problem. Generally, poor visible‐light response and fast combination of photo‐induced carriers are the main limiting factors to traditional photocatalysts. Aiming at this problem, in this paper, AgBr was used as the photosensitizer to immobilize on the surface of reduced graphene oxide (rGO) for the complexation of Ag+ ions and carboxyl groups of precursor graphene oxide (GO), then the two‐dimensional rGO‐AgBr/Ag composites (2D rGAA‐α, α = 1, 2 and 3) were synthesized by solvothermal method. The structures, morphologies, chemical bonding states and photoelectrochemical properties of the samples were analyzed to study the samples, and the corresponding visible‐light‐driven (VLD) catalytic performances were studied by hydrogen evolution reaction (HER). Compared with pure rGO, the light absorption of rGAA‐α was almost extended to full spectral range for the Z‐scheme heterointerface (rGO‐AgBr) construction, and the separation of photo‐induced carriers can be promoted effectively. The HER results showed that the average hydrogen evolution rate ( Rp) of rGAA‐α was significantly increased, and the rGAA‐2 catalyst presented the highest Rp (72.71 μmol ‐1). After six recycling experiments, the very faint activity decrease and ‐1g h unobvious structure change suggested the high photostability. Accordingly, the enhanced catalytic activity of rGAA‐α catalysts was attributed to the formation of Z‐scheme heterointerface and generation of Ag plasmas, so this study will provide a simple, effective and promising method for hydrogen energy development.
关键词： AgBr,heterostructure,Ag plasma,hydrogen evolution,reduced graphene oxide
更新于2025-09-12 10:27:22
-
Polydopamine nanospheres loaded with l-cysteine-coated cadmium sulfide quantum dots as photoelectrochemical signal amplifier for PSA detection
摘要： A sandwich-type photoelectrochemical (PEC) immunosensor was constructed for sensitive detection of prostate specific antigen (PSA). It was based on electrochemically reduced graphene oxide-TiO2 (ERGO-TiO2) as photoelectrochemical platform to immobilize capture antibody (Ab1). Then, quinone-rich polydopamine nanospheres (PDANS) loaded detection antibody (Ab2) and photocurrent signal label, L-cysteine-coated cadmium sulfide quantum dots (CdSQDs). ERGO-TiO2 displayed greatly improved photocurrent response to white light. CdSQDs conjugated with PDANS further amplified photocurrent signal because of the good conductivity of PDANS and ERGO. The increased photocurrent showed a linear correlation with PSA in the concentration range from 0.02 pg mL?1 to 200 ng mL?1 with the detection limit of 6.8 fg mL?1. It also revealed high selectivity and good stability.
关键词： Electrochemically reduced graphene oxide-TiO2,Polydopamine nanospheres,Photoelectrochemical immunosensor,L-cysteine-coated cadmium sulfide quantum dots,Prostate specific antigen
更新于2025-09-12 10:27:22
-
Plasmonic Bi nanoparticle decorated BiVO4/rGO as an efficient photoanode for photoelectrochemical water splitting
摘要： We report the application of plasmonic Bi nanoparticles supported rGO/BiVO4 anode for photoelectrochemical (PEC) water splitting. Nearly, 2.5 times higher activity was observed for Bi-rGO/BiVO4 composite than pristine BiVO4. Typical results indicated that Bi-rGO/BiVO4 exhibits the highest current density of 6.05 mA/cm2 at 1.23 V, whereas BieBiVO4 showed the current density of only 3.56 mA/cm2. This enhancement in PEC activity on introduction of Bi-rGO is due to the surface plasmonic behavior of BiNPs, which improves the absorption of radiation thereby reduces the charge recombination. Further, the composite electrode showed good solar to hydrogen conversion efficiency, appreciable incident photon-to-current efficiency and low charge transfer resistance. Hence, Bi-rGO/BiVO4 provides an opportunity to realize PEC water splitting.
关键词： Water splitting,Photoelectrochemical cell,Reduced graphene oxide,Charge transportation,Bismuth nanoparticles,Surface plasmon resonance
更新于2025-09-12 10:27:22