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Bio-template assisted hierarchical ZnO superstructures coupled with graphene quantum dots for enhanced water oxidation kinetics
摘要： Due to anisotropic growth behavior and tunable electrical properties, ZnO nanostructures having dimensions such as 0-D, 1-D, 2-D and 3-D are actively studied for their optoelectronic properties. However, ZnO based photoanodes suffer from unfavorable recombination of electron hole pair, which hinders its use in photoelectrochemical (PEC) water oxidation. Herein, we demonstrate a strategy to enhance the PEC performance using bio-template assisted in-situ grown hierarchical ZnO superstructures directly over fluorine-doped tin oxide (FTO) modified by graphene quantum dots (GQDs). GQDs decorated hierarchical ZnO superstructures displayed a significant increment of ~77% in photocurrent density value compared to pristine ZnO with an impressive carrier density of 3.19 × 1020 cm?3, which is ~1.8 orders of magnitude higher than that of pristine ZnO. It is observed that GQDs acts as an efficient hole extractor, which improves the carrier separation on ZnO surface and reduces the hole trapping probability.
关键词： Hole extracting agent,Polygalacturonic acid,Hierarchical ZnO superstructures,Photoelectrochemical water oxidation,Graphene quantum dots
更新于2025-09-23 15:19:57
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Plasmonic enhanced photoelectrochemical aptasensor with D-A F8BT/g-C3N4 heterojunction and AuNPs on a 3D-printed device
摘要： D-A F8BT/g-C3N4 type II heterojunction nanocomposite was employed as photoelectrode material for photoelectrochemical (PEC) aptasensor based on rolling circle amplification (RCA) with the assistance of 3D-printed device for carcinoembryonic antigen (CEA) detection. D-A type F8BT improved photocurrent response of g-C3N4 nanosheet after forming D-A F8BT/g-C3N4 type II heterojunction which effectively constructed built-in electric field and reduced electron-hole recombination. With the introduction of DNA-AuNP probes by π-stacking interaction, the local plasmon resonance (LSPR) of AuNPs enhanced local electric field, promoted the generation of electron-hole and further improved photocurrent response. When target CEA was in presence of sensing platform, sandwich construction was formed between two kinds of CEA aptamers and CEA on magnetic beads, triggering the RCA reaction to produce repeated sequences. Partial sequences of complementary-DNA in combination with RCA results was digested by Exo III enzyme to release signal-DNA, detaching DNA-AuNP probes from the surface of the F8BT/g-C3N4 by complementation, causing the attenuation of LSPR and the decrease of photocurrent response. Combing with 3D-printed device, this PEC aptasensor exhibited a linear response to CEA from 0.02 ng mL?1 to 50 ng mL?1 with detection limit of 6.7 pg mL?1, contributing to develop all organic polymer semiconductors as photoelectric materials in PEC study.
关键词： Type II heterojunction,Rolling circle amplification,Photoelectrochemical aptasensor,D-A F8BT/g-C3N4 nanocomposites,3D-printed device,Local surface plasmon resonance
更新于2025-09-23 15:19:57
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Multi-Walled Carbon Nanotubes/BiPO <sub/>4</sub> /BiOI Heterostructure Composite Photoelectrochemical Sensor in Detection of Salicylic Acid
摘要： In this work, BiOI, BiPO4, BiPO4/BiOI (M) and MWCNT/BiPO4/BiOI(MWCNT/M) heterostructure were synthesized through hydrothermal methods and served the function of fabricating photoelectrochemical (PEC) sensor for detection of Salicylic acid (SA). MWCNT covered with BiPO4/BiOI were observed with the aid of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Under visible light excitation, the low detection limit of 0.55 μM and working range of 1–320 μM and 480–3840 μM were obtained at the MWCNT/M/ITO. Moreover, it has excellent reproducibility and long-term stability. Meanwhile, results suggest that MWCNT/M developed herein offers a promising platform for the ultrasensitive detection of SA.
关键词： Multi-Walled Carbon Nanotubes,BiPO4/BiOI Heterostructure,Photoelectrochemical Sensor,Salicylic Acid
更新于2025-09-23 15:19:57
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Controlled Synthesis of Au Nanocrystals-Metal Selenide Hybrid Nanostructures toward Plasmon-Enhanced Photoelectrochemical Energy Conversion
摘要： A simple method for the controllable synthesis of Au nanocrystals–metal selenide hybrid nanostructures via amino acid guiding strategy is proposed. The results show that the symmetric overgrowth mode of PbSe shells on Au nanorods can be precisely manipulated by only adjusting the initial concentration of Pb2+. The shape of Au–PbSe hybrids can evolve from dumbbell-like to yolk-shell. Interestingly, the plasmonic absorption enhancement could be tuned by the symmetry of these hybrid nanostructures. This provides an e?ective pathway for maneuvering plasmon-induced energy transfer in metal–semiconductor hybrids. In addition, the photoactivities of Au–PbSe nanorods sensitized TiO2 electrodes have been further evaluated. Owing to the synergism between e?ective plasmonic enhancement e?ect and e?cient interfacial charge transfer in these hybrid nanostructures, the Au–PbSe yolk-shell nanorods exhibit an outstanding photocurrent activity. Their photocurrent density is 4.38 times larger than that of Au–PbSe dumbbell-like nanorods under light irradiation at λ > 600 nm. As a versatile method, the proposed strategy can also be employed to synthesize other metal–selenide hybrid nanostructures (such as Au–CdSe, Au–Bi2Se3 and Au–CuSe).
关键词： surface plasmon resonance,morphology manipulation,gold-metal selenide,photoelectrochemical response,hollow hybrid nanostructure
更新于2025-09-23 15:19:57
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Photocarrier relaxation pathway in selenium quantum dots and its application for UV-Vis photodetecting
摘要： Chain-like materials have recently attracted significant attention due to their unique structure and outstanding electro-optical properties. However, the photocarrier dynamics and pathways in these materials that determine the electro-optical performances of the prepared devices have barely been touched. Herein, one typical chain-like materials e quantum dots (Se QDs) were prepared via a facile liquid phase exfoliation approach. The photocarrier dynamics in selenium quantum dots were systematically investigated via ultrafast transient absorption spectroscopy in the ultraviolet-visible regime. Four photocarrier decay pathways with different lifetime times were firstly detected, endues the elucidation and reconstruction of the energy schematic diagram of Se QDs. Thanks to the broadband photo-response and fast recovery time of Se QDs, a photoelectrochemical (PEC)-typed photodetector was proposed for the first time to our knowledge, demonstrating excellent photodetection properties. Considering the feasible fabrication method and clear photocarrier pathways, the excellent photocurrent density and stability of this photodetector undoubtedly guarantee the promising of selenium for advanced photonics devices.
关键词： broadband photo-response,photocarrier dynamics,ultrafast transient absorption spectroscopy,selenium quantum dots,photoelectrochemical photodetector
更新于2025-09-23 15:19:57
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Signal amplified photoelectrochemical assay based on Polypyrrole/g-C3N4/WO3 inverse opal photonic crystals triple heterojunction assembled through sandwich-type recognition model
摘要： A novel photoelectrochemical (PEC) sensing strategy with an amplified signal was proposed based on polypyrrole/g-C3N4/WO3 inverse opal photonic crystals triple heterojunction. The sandwich-type detection model was applied to increase the sensitivity and favor the assembly of heterojunction structure. The heterojunction among PPy, g-C3N4 and WO3 highly improved the separation of photo-generated charges. Meanwhile, WO3 IOPCs with good optical performance were employed to enhance the light absorption of PEC detection electrode. With the simultaneous combination of these amplification techniques, the designed PEC sensor achieved high sensitivity with low limit of detection (LOD) as 0.004 nM (≈ 1.99 ng L?1) and admirable selectivity in the detection of oxytetracycline under visible light irradiation.
关键词： Sandwich-type,Signal amplification,Inverse opal photonic crystal,Photoelectrochemical,Heterojunction
更新于2025-09-23 15:19:57
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Incorporating graphene quantum dots to enhance the photoactivity of CdSe-sensitized TiO2 nanorods for solar hydrogen production
摘要： This work demonstrated that the incorporation of graphene quantum dots (GQDs) can greatly improve the photoelectrochemical (PEC) efficiency of CdSe-sensitized TiO2 nanorods (TiO2/CdSe), a TiO2-based visible light-responsive photoelectrode paradigm, for solar hydrogen production. For TiO2/CdSe, the accumulated holes at CdSe may induce photocorrosive oxidation to decompose CdSe, deteriorating the long-term stability of photoelectrode and degrading the PEC performance. With the introduction of GQDs, the delocalized holes can further transfer from CdSe to the GQDs, which eases the hole accumulation at the CdSe sites, thus retarding photocorrosion. Compared to the binary TiO2/CdSe photoanode, the ternary TiO2/CdSe/GQDs photoanode displays higher photocurrent and better photostability toward PEC hydrogen production. This superiority can be attributed to vectorial charge transfer and enhanced reaction kinetics provided by the introduction of GQDs. The findings from this work highlight the importance of the introduction of GQDs as a potential solution to the photocorrosion issue of chalcogenide-sensitized semiconductor photoelectrodes.
关键词： photocorrosion,photoelectrochemical efficiency,solar hydrogen production,CdSe-sensitized TiO2 nanorods,graphene quantum dots
更新于2025-09-23 15:19:57
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Highly efficient photoelectrochemical water oxidation enabled by enhanced interfacial interaction in 2D/1D In2S3@Bi2S3 heterostructures
摘要： Van der Waals (vdW) heterostructures have received tremendous attention in low dimensional semiconductors due to interfacial surface reconstruction and electronic coupling effects. Here, we report mixed-dimensional 2D/1D In2S3@Bi2S3 heterostructures synthesized via two-step solvothermal in-situ growth. Theoretical calculations demonstrate In2S3 nanosheets and Bi2S3 nanorods are integrated together through the vdW interaction. Through theoretical calculations and experiment, the results confirm the surface potential of Bi2S3 is higher than In2S3, implying the free electrons will flow from Bi2S3 to In2S3 when the two semiconductors contact, leading to electron’s and hole’s accumulation at In2S3 and Bi2S3 surface. This redistribution of charges will induce an outward vector of built-in electric field at the In2S3@Bi2S3 interface (from Bi2S3 to In2S3), thereby improving hole’s transfer to In2S3 and electron’s transfer to Bi2S3. The advanced heterostructure aids in shortening the photogenerated electrons’ transport time (14 μs), promoting the electron-hole’s separation, and presents 13.3-fold enhancement in photocurrent density when compared to In2S3.
关键词： water oxidation,photoelectrochemical,interface interaction,In2S3@Bi2S3,heterostructure
更新于2025-09-23 15:19:57
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Unassisted Water Splitting Using Standard Silicon Solar Cells Stabilized with Copper and Bi-functional NiFe Electrocatalysts
摘要： Silicon photovoltaic cells functionalized with water splitting electro-catalysts are promising candidates for unassisted water splitting. In these devices, the total surface of silicon solar cell is covered with electrocatalyst causing issues with i) stabilizing silicon solar cell in water and ii) device efficiency due to parasitic optical absorption in electrocatalyst. We describe and validate a water splitting device concept using a crystalline silicon solar cell where the front-side is covered with insulating Si3N5 antireflection coating. The Ag contacts, fired through the antireflection coating, are removed and subsequently substituted with NiFe layered double hydroxide (LDH) or Cu/NiFe-LDH electrocatlysts. In this device only the site of Ag contacts, nearly 2% of total device area is covered by the electrocatalyst. We found this small area of catalyst does not limit device performance and addition of a Cu interlayer between Si and NiFe-LDH improves device performance and stability. The unassisted water splitting efficiency of 11.31%, measured without separating the evolved gases, is achieved using a device composed of three series-connected silicon solar cells and a NiFe-LDH/Cu/Ni-foam counter electrode in a highly alkaline electrolyte.
关键词： NiFe layered double hydroxides,Photoelectrochemical Cells,Unassisted Water Splitting,Crystalline Silicon Solar Cell,Si Photocathodes
更新于2025-09-23 15:19:57
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Graphdiynea??Based Flexible Photodetectors with High Responsivity and Detectivity
摘要： Graphdiyne (GDY), a newly emerging 2D carbon allotrope, has been widely explored in various fields owing to its outstanding electronic properties such as the intrinsic bandgap and high carrier mobility. Herein, GDY-based photoelectrochemical-type photodetection is realized by spin-coating ultrathin GDY nanosheets onto flexible poly(ethylene terephthalate) (PET) substrates. The GDY-based photodetectors (PDs) demonstrate excellent photo-responsive behaviors with high photocurrent (Pph, 5.98 μA cm-2), photoresponsivity (Rph, 1086.96 μA W-1), detectivity (7.31 × 1010 Jones), and excellent long-term stability (more than 1 month). More importantly, the PDs maintain an excellent Pph after 1000 cycles of bending (4.45 μA cm-2) and twisting (3.85 μA cm-2), thanks to the great flexibility of the GDY structure that is compatible with the flexible PET substrate. Density functional theory (DFT) calculations are adopted to explore the electronic characteristics of GDY, which provides evidence for the performance enhancement of GDY in alkaline electrolyte. In this way, the GDY-based flexible PDs can enrich the fundamental study of GDY and pave the way for the exploration of GDY heterojunction-based photodetection.
关键词： photoelectrochemical,photodetection,graphdiyne,flexible devices,long-term stability
更新于2025-09-23 15:19:57