- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Effects of Au nanoparticles and ZnO morphology on the photocatalytic performance of Au doped ZnO/TiO<sub>2</sub> films
摘要： Au doped ZnO nanocomposite films on TiO2 seeding layer (AuZ/T) were fabricated by hydrothermal processing and their photocatalytic performance was investigated. It could be found that the AuZ/T with micrometer(μm)-sized, lying ZnO bulks revealed optimal photocatalytic performance toward methyl orange (MO) under simulated sunlight, whose apparent degradation rate constant Kapp of 1.31 was about 20% higher compared to that of ZnO/TiO2 and 3 times higher compared to that of ZnO. The Au nanoparticles, TiO2 seeding layer and hydrothermal processing time imposed vital influence on the morphology of ZnO nanostructures, which played key roles in the formation of ZnO/TiO2 heterojunction and charge transfer(CT) inside it, as demonstrated by kinetics of transient photoluminescence (PL) decaying. The incorporation of Au nanoparticles not only induced the variations of ZnO crystallinity and reduction of ZnO band gap (Eg), but also generated the Schottky heterojunction of metal-semiconductor, which would be beneficial to the CT inside nanocomposite films and separation of photo-generated electron-hole pairs, as verified by the remarkable PL suppression. The mechanism responsible for photocatalysis enhancement, which was resulted from the hybrid effects of Au nanoparticles and the ZnO morphology was discussed in details.
关键词： photocatalytic performance,Au doped ZnO,heterojunction,TiO2
更新于2025-09-09 09:28:46
-
Facile construction of a molybdenum disulphide/zinc oxide nanosheet hybrid for an advanced photocatalyst
摘要： Zinc oxide, an important semiconductor material with good stability, is widely used in photocatalytic degradation of organic pollutants. MoS2 is a two-dimensional semiconductor material. When molybdenum disulphide has more sulfur elements exposed, the photocatalytic activity can be improved. Through the hydrothermal method, zinc oxide nanosheets and molybdenum disulphide nanosheets were successfully supported to form MoS2-ZnO heterojunctions. The surface area of these heterojunctions is large, and they expose more sulfur elements which can effectively promote the separation of photo-generated electrons and holes, and improve the photocatalytic performance of MoS2-ZnO heterojunctions. The photocatalytic degradation of Rhodamine B by MoS2-ZnO heterojunctions was completed in one hour. MoS2-ZnO heterojunctions are environmentally friendly photocatalysts that do not pollute the environment when they degrade organic pollutants in water.
关键词： Photocatalyst,Zinc oxide,Molybdenum disulphide,Heterojunction
更新于2025-09-09 09:28:46
-
Synthesis of Flower-Like AgI/BiOCOOH p-n Heterojunctions With Enhanced Visible-Light Photocatalytic Performance for the Removal of Toxic Pollutants
摘要： In this study, flower-like AgI/BiOCOOH heterojunctions were constructed through a two-step procedure involving the solvothermal synthesis of BiOCOOH microflowers followed by AgI modification using a precipitation method. These novel photocatalysts were systematically examined by XRD, UV–vis DRS, SEM, TEM, EDS, and PL spectroscopy techniques. The AgI/BiOCOOH heterojunction were studied as a decent photocatalyst for the removal of the industrial dye (rhodamine B, and methyl blue) and antibiotic (tetracycline) under visible light. The AgI/BiOCOOH heterojunctions are much more active than bare BiOCOOH, and AgI, which could be ascribed to the improved separation of charge carriers, resulting from the formation of p-n heterojunction between two constituents. The holes (h+) and superoxide radical (?O?2 ) were detected as the main active species responsible for the pollutant degradation. The results showed that a highly efficient visible-light-driven photocatalytic system was developed for the decomposition of toxic pollutants.
关键词： antibiotic removal,dye removal,p-n heterojunction,AgI/BiOCOOH,photocatalysis
更新于2025-09-09 09:28:46
-
CuO <sub/>x</sub> -TiO <sub/>2</sub> Composites: Electronically Integrated Nanocomposites for Solar Hydrogen Generation
摘要： CuOx-TiO2 (CT) composites were prepared by different methods (impregnation, microwave and photodeposition methods) and evaluated for solar water splitting (SWS) with aqueous methanol. CT composites prepared by three different methods were characterized by relevant methods to understand the correlation between synthesis method and activity, and the mechanism of water splitting. A comparison of photocatalytic activity of CT composite materials indicates that the photocatalyst prepared by photodeposition method shows significantly improved activity for hydrogen production from aqueous methanol as well as with water (overall water splitting) under one sun conditions. Cu is present in Cu/Cu + 1 form in photodeposition method prepared CT, which is more effective and helpful for solar light absorption as well as charge carrier separation due to the formation of bulk p-n (Cu2O-TiO2) heterojunctions. However, CuO formation seems to decrease the activity with other preparation methods.
关键词： titania,solar hydrogen,photocatalysis,copper oxide,heterojunction
更新于2025-09-09 09:28:46
-
Noise Analysis of Group IV Material-Based Heterojunction Phototransistor for Fiber-Optic Telecommunication Networks
摘要： This paper presents an analytical study of noise behavior and spectral responsivity of Ge1?xSnx alloy-based heterojunction phototransistors (HPTs) for different Sn compositions and base doping concentrations. The structure consists of n-Ge/p-Ge1?xSnx layers pseudomorphically grown on Si substrate via Ge virtual substrate, compatible with complementary metal-oxide-semiconductor technology. The high absorption coefficient of the alloy in base significantly improves signal-to-noise ratio in the high-frequency region, leading to efficient photodetection in the C- and L-bands of fiber-optic telecommunication window. A comparison is made between the theoretical findings for GeSn HPTs and the available data for currently employed group III–V compound-based HPTs, to examine if GeSn-based HPT can be a good alternative.
关键词： GeSn alloys,absorption coefficient,spectral responsivity,heterojunction phototransistor,signal-to-noise ratio
更新于2025-09-09 09:28:46
-
A 128-Pixel System-on-a-Chip for Real-Time Super-Resolution Terahertz Near-Field Imaging
摘要： This paper presents a fully integrated system-on-a-chip for real-time terahertz super-resolution near-field imaging. The chip consists of 128 sensing pixels with individual cross-bridged double 3-D split-ring resonators arranged in a 3.2 mm long 2 × 64 1-D array. It is implemented in 0.13-μm SiGe bipolar complementary metal–oxide–semiconductor technology and operated at around 550 GHz. All the functions, including sensor illumination, near-field sensing, and detection, are co-integrated with a readout integrated circuit for real-time image acquisition. The pixels exhibit a permittivity-based imaging contrast with a worst case estimated relative permittivity uncertainty of 0.33 and 10–12-μm spatial resolution. The sensor illumination is provided with on-chip oscillators feeding four-way equal power divider networks to enable an effective pixel pitch of 25 μm and a dense fill factor of 48% for the 1-D sensing area. The oscillators are equipped with electronic chopping to avoid 1/f-noise-related desensitization for the SiGe-heterojunction bipolar transistor power detectors integrated at each pixel. The chip features both an analog readout mode and a lock-in-amplifier-based digital readout mode. In the analog readout mode, the measured dynamic range (DR) is 63.8 dB for a 1-ms integration time at an external lock-in amplifier. The digital readout mode achieves a DR of 38.5 dB at 28 f/s. The chip consumes 37–104 mW of power and is packaged into a compact imaging module. This paper further demonstrates real-time acquisition of 2-D terahertz super-resolution images of a nickel mesh with 50-μm feature size, as well as a biometric human fingerprint.
关键词： terahertz,system-on-a-chip (SoC),SiGe heterojunction bipolar transistor (HBT),split-ring resonator (SRR),near-field array,3-push Colpitts oscillator,super-resolution imaging,near-field scanning optical microscopy (NSOM),power detector
更新于2025-09-09 09:28:46
-
Optimizing nanoscale morphology and improving Carrier transport of PCDTBT-PCBM bulk heterojunction by cyclic carboxylate nucleating agents
摘要： In this work, four cyclic carboxylate commercial nucleating agents, bicyclo [2.2.1] heptane-2,3-dicarboxylic acid disodium salt (HPN-68L), sodium salt of hexahydrophthalic acid (HHPA-Na), sodium benzoate (Be-Na) and calcium salt of hexahydrophthalic acid (HPN-20E) were respectively added into poly[N-9’-heptadecanyl-2,7-carbazole-alt-5,5-(4’,7’-di-2-thienyl-2’,1’,3’ benzothiadi-azole)] (PCDTBT)-[6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend. Atomic force microscopy (AFM) and UV-vis measurements indicate that the addition of carboxylic acid sodium salts can effectively optimize the morphology of active layer, decrease the phase domain size and increase the optical absorption intensity of PCDTBT-PCBM blends. The PCDTBT-PCBM-additive ternary devices were fabricated and found that adding carboxylic acid sodium salts can improve the hole mobility, balance the hole and electron mobility and finally increase the power conversion efficiency (PCE). Fixed the additive content as 5%, the modulation ability of the bicyclic dicarboxylic acid sodium salt HPN-68L is best, monocyclic dicarboxylic acid sodium salt HHPA-Na comes second, monocyclic carboxylic acid sodium salt Be-Na is worst. The addition of carboxylic acid calcium salt HPN-20E has no effects on the morphology and optical absorption intensity of the PCDTBT-PCBM blend, and the photoelectric properties of PCDTBT-PCBM-HPN-20E ternary device decreases in comparison with those of pristine PCDTBT-PCBM binary device. The modulation ability of cyclic carboxylate is related to its surface free energy and its location in the PCDTBT-PCBM blend. HPN-68L locates in the interfacial region between PCDTBT and PCBM, other cyclic carboxylates locates in the PCBM. Our finding suggests the addition of cyclic carboxylic acid sodium salts can be a facile approach to optimize the morphology and increase the electrical properties of organic materials for future development of organic photovoltaic devices.
关键词： PCDTBT-PCBM bulk heterojunction,carrier transport,organic photovoltaic devices,cyclic carboxylate nucleating agents,nanoscale morphology
更新于2025-09-09 09:28:46
-
Comprehensive Analysis and Optimal Design of Ge/GeSn/Ge p-n-p Infrared Heterojunction Phototransistors
摘要： We present a comprehensive analysis of practical p-n-p Ge/Ge1?xSnx/Ge heterojunction phototransistors (HPTs) for design optimization for efficient infrared detection. Our design includes a Ge1?xSnx narrow-bandgap semiconductor as the active layer in the base layer, enabling extension of the photodetection range from near-infrared to mid-infrared to perform wide-range infrared detection. We calculate the current gain, signal-to-noise ratio (SNR), and optical responsivity and investigate their dependences on the structural parameters to optimize the proposed Ge1?xSnx p-n-p HPTs. The results show that the SNR is strongly dependent on the operation frequency and that the introduction of Sn into the base layer can improve the SNR in the high-frequency region. In addition, the current gain strongly depends on the Sn content in the Ge1?xSnx base layer, and a Sn content of 6%–9% maximizes the optical responsivity achievable in the infrared range. These results provide useful guidelines for designing and optimizing practical p-n-p Ge1?xSnx HPTs for high-performance infrared photodetection.
关键词： current gain,sign-to-noise ratio,infrared,heterojunction phototransistors,GeSn alloys
更新于2025-09-09 09:28:46
-
Short/mid-wave two-band type II superlattice infrared heterojunction phototransistor
摘要： We report on a short/mid-wave (SW/MW) two-band type II InAs/GaSb superlattice (SL) infrared heterojunction phototransistor (HPT). The structure consists of two back-to-back HPTs for the SW and MW detections. At 77 K, the 50% cut-off wavelength of the SW and MW HPT is 2.6 and 4.2 (cid:22)m, respectively. When the applied bias voltage is 1.2 V, the responsivity is 213 A/W and the current gain is 611 for the SW band while for the MW band, the responsivity is 45.2 A/W and the current gain is 377 at bias voltage of 1.3 V. At 1.2 V, the shot noise limited detectivity D(cid:3) of the SW channel and the MW channel is 1.9(cid:2)1011 and 1.7(cid:2)109 cm(cid:1)Hz0:5/W, respectively.
关键词： two-band detection,Heterojunction phototransistor,current gain,type II InAs/GaSb superlattice
更新于2025-09-09 09:28:46
-
Microwave-assisted preparation and enhanced photocatalytic activity of Bi2WO6/BiOI heterojunction for organic pollutants degradation under visible-light irradiation
摘要： In this research, we adopted morphology control and constructing p-n heterojunction to boost the photocatalytic performance of BiOI. BiOI with three morphologies (nanoplate, micro-flower, microsphere) was fabricated via a wet-chemical method at room temperature using different solvents. And Bi2WO6/BiOI microspheres were successfully prepared by a microwave-assisted synthetic method. The as-synthesized samples were characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and High-resolution Transmission Electron Microscopy (HRTEM). The results of photo-degradation experiment demonstrated that BiOI-3 and BWOI-3 show high photocatalytic performance towards methyl orange (MO) and bisphenol A (BPA) degradation due to the high specific surface area, synergistic effect between p-type BiOI and n-type Bi2WO6 and high separation efficiency of electron-hole pairs, which is verified by Brunauer-Emmett-Teller (BET), Photocurrent (PC) and Electrochemical Impedance Spectroscopy (EIS) analysis. Moreover, the repeated photocatalytic experiment was carried out by using MO as the representative organic pollutant, manifesting the good durability of the sample.
关键词： Microwave-assisted,Heterojunction,Bi2WO6,Photocatalytic activity,BiOI
更新于2025-09-09 09:28:46