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Network Structured CuWO4/BiVO4/Co-Pi Nanocomposite for Solar Water Splitting
摘要： A network structured CuWO4/BiVO4 nanocomposite with a high specific surface area was prepared from CuWO4 nanoflake (NF) arrays via a method that combined drop-casting and thermal annealing. The obtained CuWO4/BiVO4 exhibited high catalytic activity toward photoelectrochemical (PEC) water oxidation. When cobalt phosphate (Co-Pi) was coupled with CuWO4/BiVO4, the activity of the resulting CuWO4/BiVO4/Co-Pi composite for the oxygen evolution reaction (OER) was further improved. The photocurrent density (Jph) for OER on CuWO4/BiVO4/Co-Pi is among the highest reported on a CuWO4-based photoanode in a neutral solution. The high activity for the PEC OER was attributed to the high specific surface area of the composite, the formation of a CuWO4/BiVO4 heterojunction that accelerated electron–hole separation, and the coupling of the Co-Pi co-catalyst with CuWO4/BiVO4, which improved the charge transfer rate across composite/solution interface.
关键词： copper tungstate,cobalt phosphate,oxygen evolution reaction,bismuth vanadate,photoelectrochemical water splitting
更新于2025-09-23 15:22:29
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Multifunctional monoclinic VO2 nanorod thin films for enhanced energy applications: Photoelectrochemical water splitting and supercapacitor
摘要： Monoclinic VO2 nanorod thin films were deposited on indium?tin-oxide-coated glass substrates using radio-frequency reactive magnetron sputtering at a substrate temperature of 300 °C and various O2 flow rates. The thin films were characterized via standard analysis techniques. The VO2 thin films exhibited a highly crystalline monoclinic phase with an indirect band gap of ~1.73 eV. At optimized O2 flow rate (4 sccm), the thin films was observed nanorod structures, exhibited a remarkable photocurrent of ~0.08 mA cm?2 during photoelectrochemical water splitting in the visible region. Electrochemical performance tests of the nanorod films revealed a specific capacitance of ~486 mF cm?2 at a scan rate of 10 mVs?1. In addition, amperometric I–t curves showed that VO2 thin film electrodes were highly stable during the photo-oxidation process. The nanorod films also exhibited a good specific capacitance of ~120 mF cm?2 after 5000 cycles at a scan rate of 100 mVs?1. The photocurrents during photoelectrochemical water splitting and the specific capacitance of VO2 thin films deposited at O2 flow rates of 2 and 6 sccm were 0.06 and 0.07 mA cm?2 and 398 and 37 mF cm?2, respectively. The films deposited under Ar at 8 sccm and O2 at 4 sccm showed the highest photoelectrochemical water splitting performance and specific capacitance, owing mainly to their nanorod-like morphology.
关键词： Supercapacitor,Partial pressure,Reactive sputtering,Photoelectrochemical water splitting,VO2,Monoclinic
更新于2025-09-23 15:22:29
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Evidencing enhanced charge-transfer with superior Photocatalytic degradation and Photoelectrochemical water splitting in Mg modified few-layered SnS2
摘要： Recently there has been immense interest in the exploration of richly available two-dimensional non-toxic layered material such as tin disulfide (SnS2) for potential employment in energy and environmental needs. In this regard, we report on the synthesis of few-layered Sn1?xMgxS2 nanosheets through a facile one-step hydrothermal route to address all such functions concerning photocatalysis and photoelectrochemical conversion. The crystalline order and structure of processed layered Sn1?xMgxS2 were initially found to exhibit a strong influence on their physicochemical properties. Their optical properties attest the Mg doping in SnS2 to benefit us with enhanced visible-light absorption via red-shift in their absorption edge. In the photoluminescence spectrum the emissions observed along visible and red region signifies the association of Mg related trap states in Sn1?xMgxS2. Next, the photocurrent and electrochemical impedance spectroscopic results revealed the Mg doping to promote the effective charge transfer process (which was beneficial to enhance their photocatalytic activity). Consequently, the layered Sn0.98Mg0.02S2 made photoanodes displayed 1.7 fold higher photocurrent density under simulated solar radiation with respect to their undoped counterpart. Furthermore, the layered Sn0.98Mg0.02S2 nanosheets exhibits enhanced visible light decomposition of organic dye while compared with pristine SnS2 nanosheets. The value of rate constants obtained for the Sn0.98Mg0.02S2 nanosheets was found to be 1.4 times higher than that of pristine SnS2. Finally, the results obtained through the present study projects the huge potential of layered Sn0.98Mg0.02S2 nanosheets for future multifunctional applications.
关键词： SnS2,Magnesium,Nanosheets,Photocatalysis,Few-layered,Photoelectrochemical water splitting
更新于2025-09-23 15:22:29
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Nanostructuring Strategies To Increase the Photoelectrochemical Water Splitting Activity of Silicon Photocathodes
摘要： Photoelectrochemical water splitting is a promising route for sustainable hydrogen production. Herein, we demonstrate a photoelectrode motif that enables a nanostructured large-surface area electrocatalyst without requiring a nanostructured semiconductor surface with the goal of promoting electrocatalysis while minimizing surface recombination. We compare the photoelectrochemical H2 evolution activity of two silicon photocathode nanostructuring strategies: (1) direct nanostructuring of the silicon surface and (2) incorporation of nanostructured zinc oxide to increase the electrocatalyst surface area on planar silicon. We observed that silicon photocathodes that utilized nanostructured ZnO supports outperformed nanostructured silicon electrodes by ～50 mV at open circuit under 1 sun illumination and demonstrated comparable electrocatalytic activity.
关键词： photocathodes,silicon nanowires,hydrogen evolution,molybdenum disulfide,zinc oxide nanowires,photoelectrochemical water splitting
更新于2025-09-23 15:22:29
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Enhanced Charge Transport and Increased Active Sites on α-Fe <sub/>2</sub> O <sub/>3</sub> (110) Nanorod Surface Containing Oxygen Vacancies for Improved Solar Water Oxidation Performance
摘要： The e?ect of oxygen vacancies (VO) on α-Fe2O3 (110) facet on the performance of photoelectrochemical (PEC) water splitting is researched by both experiments and density functional theory (DFT) calculations. The experimental results manifest that the enhancement in photocurrent density by the presence of VO is related with increased charge separation and charge-transfer e?ciencies. The electrochemical analysis reveals that the sample with VO demonstrates an enhanced carrier density and reduced charge-transfer resistance. The results of DFT calculation indicate that the better charge separation is also contributed by the decrease of potential on the VO surface, which improves the hole transport from the bulk to the surface. The reduced charge-transfer resistance is owing to the greatly increased number of active sites. The current study provides important insight into the roles of VO on α-Fe2O3 photoanode, especially on its surface catalysis. The generated lesson is also helpful for the improvement of other PEC photoanode materials.
关键词： oxygen vacancies,α-Fe2O3,photoelectrochemical water splitting,charge-transfer efficiencies,density functional theory,charge separation
更新于2025-09-23 15:21:21
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Angstrom Thick ZnO Passivation Layer to Improve the Photoelectrochemical Water Splitting Performance of a TiO2 Nanowire Photoanode: The Role of Deposition Temperature
摘要： In this paper, we demonstrate that angstrom thick single atomic layer deposited (ALD) ZnO passivation can significantly improve the photoelectrochemical (PEC) activity of hydrothermally grown TiO2 NWs. It is found that this ultrathin ZnO coating can passivate the TiO2 surface defect states without hampering the carrier’s transfer dynamics. Moreover, a substantial improvement can be acquired by changing the deposition temperature of the ZnO layer (80 °C, and 250 °C) and named as 80 °C TiO2-ZnO, and 250 °C TiO2-ZnO. It was found that the deposition of this single layer in lower temperatures can lead to higher PEC activity compared to that deposited in higher ones. As a result of our PEC characterizations, it is proved that photoconversion efficiency of bare TiO2 NWs can be improved by a factor of 1.5 upon coating it with a single ZnO layer at 80 °C. Moreover, considering the fact that this layer is a passivating coating rather than a continuous layer, it also keeps the PEC stability of the design while this feature cannot be obtained in a thick shell layer case. This paper proposes a bottom up approach to control the electron transfer dynamics in a heterojunction design and it can be applied to other metal oxide combinations.
关键词： deposition temperature,atomic layer deposition,photoelectrochemical water splitting,ZnO passivation,TiO2 nanowire
更新于2025-09-23 15:21:01
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Photoelectrochemical performances of Fe2O3 nanotube films decorated with cadmium sulfide nanoparticles via photo deposition method
摘要： Hematite is an appropriate compound for photoelectrochemical water splitting. However, passive surface state, high recombination rate of the photo induced electron-hole pairs and poor and slow charge transfer kinetics restrict the performance of hematite. In this work, CdS/Fe2O3NTs samples have been successfully prepared by coating of CdS nanoparticles on the surface of the self-organized Fe2O3NTs via photo deposition technique in order to enhance charge separation and charge transfer kinetics. FESEM (Field Emission Scanning Electron Microscopy), XRD (X-ray diffraction), DRS (Diffraction Reflection Spectroscopy) and XPS (X-ray Photoelectron Spectroscopy) analyses have been used to characterize the CdS/Fe2O3NTs photoelectrodes obtained. CdS/Fe2O3NTs has an intense visible light absorption and displays a red-shift of the band edge in comparison with the bare Fe2O3NTs, according to DRS test. The photocurrent density of Fe2O3NTs increased approximately 5 times upon coating with CdS, as shown by photoelectrochemical measurements, indicating the significant role of the introduction of CdS in the enhancement of photo catalytic activity. CdS/Fe2O3NTs may be promising and effective photoanodes in PEC water splitting given their simple preparation and good performance.
关键词： Cadmium sulfide,Photo deposition,Fe2O3 nanotube,Photoelectrochemical water splitting
更新于2025-09-23 15:21:01
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Ternary Hierarchical Cu <sub/>7</sub> S <sub/>4</sub> /TiO <sub/>2</sub> /CoCr-LDH Heterostructured Nanorod Arrays with Multiphase Reaction Interfaces for More Efficient Photoelectrochemical Water Splitting
摘要： Fabricating hierarchical and highly matched heterostructure with large surface areas and multiple interfaces is an effective approach to enhancing the photoelectrochemical performance. Here, well-aligned hierarchical Cu7S4/TiO2/CoCr-layered double hydroxide (LDH) nanorod arrays are reported, aiming at accelerating charge separation and transfer kinetics. The modifications of Cu7S4 and CoCr-LDH based on TiO2 have endowed the photoanode a surprising enhancement in both ultraviolet light absorption and charge separation efficiency due to highly matched band alignment. The formation of heterojunction is an effective strategy to prevent photocorrosion of Cu7S4 by attaching protective layers on Cu7S4. Moreover, other than the hierarchical morphology with enlarged active surface areas would provide sufficient active sites for the water oxidation processes and pore channels for the gas escaping, owing to the special band alignment of three components, multiple reaction interfaces are produced and involved in the water splitting process, since the photoinduced holes for water oxidation are simultaneously distributed in CoCr-LDH and Cu7S4. As expected, this synergistic effect in this ternary Cu7S4/TiO2/CoCr-LDH heterogeneous photoanode gives rise to a largely enhanced photoconversion efficiency (0.58% at 0.6 V) and photocurrent density (2.04 mA cm?2 at 1.23 V).
关键词： 3D hierarchical nanorod arrays,Cu7S4/TiO2/CoCr-LDH,ternary heterostructure,highly matched band alignment,photoelectrochemical water splitting
更新于2025-09-23 15:21:01
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<i>In situ</i> growth of α-Fe <sub/>2</sub> O <sub/>3</sub> @Co <sub/>3</sub> O <sub/>4</sub> core–shell wormlike nanoarrays for a highly efficient photoelectrochemical water oxidation reaction
摘要： Photoelectrochemical (PEC) water splitting represents a promising strategy to convert solar energy into chemical energy in the form of hydrogen, but its performance is severely limited by the sluggish water oxidation reaction. Herein, for the first time, we report the direct assembly of an ultrathin, uniform, and dense layer of Co3O4 on wormlike nanostructured hematite (WN-α-Fe2O3) to form a large-area and high-density WN-α-Fe2O3@Co3O4 core–shell nanoarray via in situ hydrothermal growth followed by calcination, in which the electrostatic force between WN-α-Fe2O3 and the reactants, pH- and temperature-controlled structures of WN-α-Fe2O3, and ultralow nucleation rate of Co3O4 precursors all play critical roles. The obtained heteronanostructure array shows a photocurrent density of 3.48 mA cm?2, which is 4.05 times higher than that of pristine WN-α-Fe2O3 (0.86 mA cm?2), an onset potential of ～0.62 V, 60 mV lower than that of α-Fe2O3 (～0.68 V), and a photoconversion efficiency of 0.55%, 3.93 times higher than that of WN-α-Fe2O3 (0.14%). This is among the highest performances reported for Fe2O3-based photoanodes for water splitting. It is discovered that the Co3O4 shells can significantly enhance the charge separation, accelerate the charge transport and transfer, and reduce the charge transfer resistance from the photoelectrode to the electrolyte for a fast water oxidation reaction, thereby greatly promoting the PEC water oxidation performance of pristine WN-α-Fe2O3. This work not only creates a novel low-cost and Earth-abundant WN-α-Fe2O3@Co3O4 photoelectrode with superior PEC water oxidation performance and provides scientific insights into the enhancement mechanism, but also offers a general strategy for the in situ growth of water oxidation catalysts on various photoelectrodes with 3-D complex geometries for PEC water splitting.
关键词： α-Fe2O3,water oxidation reaction,Co3O4,Photoelectrochemical water splitting,core–shell nanoarray
更新于2025-09-23 15:19:57
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Strong Lighta??matter Interaction in Au Plasmonic Nanoantennas Coupled with Prussian Blue Catalyst on BiVO4 for Photoelectrochemical Water Splitting
摘要： We establish a facial and large scale compatible fabrication route affording a high performance heterogeneous plasmonic-based photoelectrode for water oxidation that incorporates a CoFe-Prussian blue analog (PBA) structure as the water oxidation catalytic center. For this purpose, an angled deposition of gold (Au) was used to selectively coat the tips of the bismuth vanadate (BiVO4) nanostructures, yielding Au capped BiVO4 (Au-BiVO4). The formation of multiple size/dimension Au capping islands provides strong light-matter interaction at nanoscale dimensions. These plasmonic particles not only enhance light absorption in the bulk BiVO4 (through the excitation of Fabry-Perot (FP) modes) but also contribute to photocurrent generation via the injection of sub-bandgap hot electrons. To substantiate the activity of the photoanodes, the interfacial electron dynamics is significantly improved using a PBA water oxidation catalyst (WOC) resulting in Au-BiVO4/PBA assembly. At 1.23 V vs RHE, the photocurrent value for a bare BiVO4 photoanode was obtained as 190 μA cm?2, while it was boosted to 295 μA cm?2, and 1,800 μA cm?2 for Au-BiVO4, and Au-BiVO4/PBA, respectively. Our results suggest that this simple and facial synthetic approach paves the way for plasmonic-based solar water splitting, in which a variety of common metals and semiconductors can be employed in conjunction with catalyst designs.
关键词： photoelectrochemical water splitting,Prussian blue,plasmonics,hot electron,cyanide chemistry
更新于2025-09-23 15:19:57