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Photocathodic hydrogen evolution from catalysed nanoparticle films prepared from stable aqueous dispersions of P3HT and PCBM
摘要： Photo-assisted hydrogen evolution is achieved on photocathodes comprising of nanoparticles of poly(3-hexylthiophene) (npP3HT) and nanoparticles of phenyl-C61-butyric acid methyl ester (npPCBM) onto which ultra-low loadings of Pt nanoparticles are deposited. The nanoparticles, npP3HT and npPCBM, are prepared individually via miniemulsion using surfactants of opposite head group polarity. Aqueous dispersions of npP3HT:npPCBM, devoid of organic solvent, are cast conformally onto ITO-coated glass to yield water-insoluble bulk-heterojunction films. Pt is deposited photoelectrochemically onto ITO/npP3HT:npPCBM photocathodes and found to nucleate preferentially on PCBM nanoparticles. ITO/npP3HT:npPCBM/Pt photocathodes produce 65 μA/cm2 photocurrent under 100 mW/cm2 of visible light at 0.0 VSHE and liberate H2 gas. The photocurrents observed for electrodes prepared using npP3HT:npPCBM are twice as large, and the onset potential is ～0.4 V more positive than analogous photocathodes cast from nanoparticles each comprising an intimate blend of P3HT and PCBM. These are encouraging results for large scale synthesis of organic photoelectrochemical devices, given the simplicity of the photoelectrode, i.e., prepared from aqueous solutions and devoid of vacuum-deposited films such as charge transport layers and protective films.
关键词： Polymer nanoparticle,Photoelectrochemistry,P3HT: PCBM bulk-heterojunction,Solar hydrogen generation,Organic semiconductor,Mini-Emulsion
更新于2025-09-23 15:23:52
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Nitrogen-doped Graphene Quantum Dots for Remarkable Solar Hydrogen Production
摘要： We synthesized nitrogen (N)-doped graphene quantum dots (N-GQDs) using a top-down hydrothermal cutting approach. The concentration of N dopants was readily controlled by adjusting the concentration of the N source of urea. When N dopants were incorporated into GQDs, visible absorption was induced by C-N bonds, which created another pathway for generating photoluminescence (PL). Time-resolved PL data revealed that the carrier lifetime of GQDs was increased upon doping with the optimized N concentration. The photoelectrochemical properties of N-GQDs towards water splitting were studied, and the results showed that 2N-GQDs prepared with 2 g of urea produced the highest photocurrent. The photocatalytic activity of 2N-GQDs powder photocatalyst for hydrogen production was also examined under AM 1.5G illumination, showing substantial enhancement over that of pristine GQDs. Electrochemical impedance spectroscopy data further revealed a significant improvement in charge dynamics and reaction kinetics, and an increased carrier concentration as a result of N doping.
关键词： Solar Hydrogen Production,Charge Dynamics,Water Splitting,Graphene Quantum Dots,Nitrogen-doped
更新于2025-09-23 15:21:01
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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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Prospects for Hermetic Sealing of Scaled-Up Photoelectrochemical Hydrogen Generators for Reliable and Risk Free Operation
摘要： Photo-electrochemical (PEC) systems have the potential to contribute to de-carbonation of the global energy supply because solar energy can be directly converted to hydrogen, which can be burnt without the release of greenhouse gases. However, meaningful deployment of PEC technology in the global energy system, even when highly e?cient scaled up devices become available, shall only be a reality when their safe and reliable operation can be guaranteed over several years of service life. The ?rst part of this review discusses the importance of hermetic sealing of up scaled PEC device provided by the casing and sealing joints from a reliability and risk perspective. The second part of the review presents a survey of fully functional devices and early stage demonstrators and uses this to establish the extent to which the state of the art in PEC device design address the issue of hermetic sealing. The survey revealed that current material choices and sealing techniques are still unsuitable for scale–up and commercialization. Accordingly, we examined possible synergies with related photovoltaic and electrochemical devices that have been commericalised, and derived therefrom, recommendations for future research routes that could accelerate the development of hermetic seals of PEC devices.
关键词： hermetic sealing,safety,photo-electrochemical,reliability,scale-up,solar hydrogen generator
更新于2025-09-16 10:30:52
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A Three-Dimensional ZnO/CdS/NiFe Layered Double Hydroxide Photoanode Coupled with a Cu <sub/>2</sub> O Photocathode in a Tandem Cell for Overall Solar Water Splitting
摘要： An integrated tandem photoelectrochemical (PEC) cell, composed of a three-dimensional (3D) ZnO/CdS/NiFe layered double hydroxide (LDH) core/shell/hierarchical nanowire arrays (NWAs) photoanode and a p-Cu2O photocathode, was designed for unassisted overall solar water splitting in this study. The optical and photoelectrochemical characteristics of ZnO-based photoanodes and Cu2O photocathode were investigated. The results show that ZnO/CdS/NiFe LDH nanostructures offer significantly enhanced performances with a photocurrent density reaching 5.8 mA cm?2 at 0.9 V and an onset potential as early as 0.1 V (versus RHE). The enhancement can be attributed to the existence of CdS nanoparticles (NPs) which boosts the light absorption in visible region and enhances charge separation. Moreover, the introduction of NiFe LDH nanoplates, with unique hierarchical mesoporous architecture, promotes electrochemical reactions by providing more active sites as co-catalyst. On the above basis, the ZnO/CdS/NiFe LDH–Cu2O two-electrode tandem cell system was established. At zero bias, the device shows a photocurrent density of 0.4 mA cm?2 along with the corresponding solar-to-hydrogen (STH) conversion efficiency reaching 0.50%. Our results indicate that the tandem PEC cells consisting of metal–oxide–semiconductor photoelectrodes based on Earth-abundant and low-cost materials hold promising application potential for overall solar water splitting.
关键词： ZnO,PEC tandem cell,CdS,solar hydrogen,self-driven water splitting,NiFe LDH
更新于2025-09-12 10:27:22
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Electrochemically controlled CdS@CdSe nanoparticles on ITO@TiO2 dual core-shell nanowires for enhanced photoelectrochemical hydrogen production
摘要： Here, we report a novel dual heterostructured photoanode consisting of CdS@CdSe core-shell nanoparticles (NPs) and 1D-structure tin-doped indium oxide (ITO)@TiO2 core-shell nanowires (ITO@TiO2@CdS@CdSe) for highly efficient photoelectrochemical (PEC) hydrogen production. The finely controlled hierarchical core-shell CdS@CdSe sensitization from consecutive electrochemical deposition on the ITO@TiO2 core-shell nanowire has synergistic effects of visible-light utilization and efficient charge transport on the PEC response. The rationally designed dual core-shell heterostructure leads to cascade charge migration throughout the aligned energy band edges with rapid charge extraction through the hierarchical heterostructure of ITO@TiO2@CdS@CdSe, alleviating the crucial charge accumulation. As a result, the dual heterostructured photoanode exhibits a maximum photocurrent density of 20.11 mA/cm2 at 1.23 V vs. the reversible hydrogen electrode (RHE) and a dramatic enhancement in the incident photon-to-current efficiency (IPCE) over the extended absorption spectrum. The time-resolved photoluminescence (TRPL) characterization indicates the realized multiple-band cascade charge migration throughout ITO@TiO2@CdS@CdSe could promote an 8-fold increase in the charge separation efficiency. This rational design of dual-heterojunction-structured photoelectrodes via electrochemical deposition provides a demonstration of modifying conventional light-harvesting photoelectrodes with stagnate solar energy conversion and PEC hydrogen production.
关键词： cascade charge transport,solar hydrogen production,electrochemical core-shell deposition,photoelectrochemical cell,dual heterostructure
更新于2025-09-11 14:15:04
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An efficient tandem photoelectrochemical cell composed of FeOOH/TiO2/BiVO4 and Cu2O for self-driven solar water splitting
摘要： An integrated solar water splitting tandem cell without external bias was designed using a FeOOH modified TiO2/BiVO4 photoanode as a photoanode and p-Cu2O as a photocathode in this study. An apparent photocurrent (0.37 mA/cm2 at operating voltage of +0.36 VRHE) for the tandem cell without applied bias was measured, which is corresponding to a photoconversion efficiency of 0.46%. Besides, the photocurrent of FeOOH modified TiO2/BiVO4 and Cu2O photocathode (~0.07 mA/cm2 at +0.42 VRHE). Then we established a FeOOH modified TiO2/BiVO4-Cu2O two-electrode system and measured the current density-voltage curves under AM 1.5G illumination. The unassisted photocurrent density is 0.12 mA/cm2 and the corresponding amounts of hydrogen and oxygen evolved by the tandem PEC cell without bias are 2.36 mmol/cm2 and 1.09 mmol/cm2 after testing for 2.5 h. The photoelectrochemical (PEC) properties of the FeOOH modified TiO2/BiVO4 photoanode were further studied to demonstrate the electrons transport process of solar water splitting. This aspect provides a fundamental challenge to establish an unbiased and stabilized photoelectrochemical (PEC) solar water splitting tandem cell with higher solar-to-hydrogen efficiency.
关键词： Self-driven water splitting,PEC tandem cell,Solar hydrogen,Cu2O-BiVO4
更新于2025-09-10 09:29:36
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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
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Accumulation of Solar Hydrogen in the Photoelectrochemical System Based on CdSe Photoanode and MH Cathode
摘要： The film photoanodes based on CdSe and NT-TiO2/CdSe have been formed by the electrochemical and painting methods. It is shown that the introduction of graphene oxide into the structure of the semiconductor CdSe film promotes absorption of light and leads to improvement in their characteristics by 25-30 %. The compatibility of the cathode based on composite of hydrogen-sorbing intermetallic alloys LaNi4.5Mn0.5 + LaNi3.5Al0.7Mn0.8 with current-conductive additives in pair with the CdSe photoanode is shown. It was found that 95 – 98 % of the total current generated under the influence of sunlight at the anodes was used on the formation and accumulation of hydrogen by cathodes.
关键词： photoelectrochemical system,photoanode,CdSe,solar hydrogen,MH cathode
更新于2025-09-09 09:28:46
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Effective quenching and excited-state relaxation of a Cu(I) photosensitizer addressed by time-resolved spectroscopy and TDDFT calculations
摘要： Homogenous photocatalytic systems based on copper photosensitizers are promising candidates for noble metal free approaches in solar hydrogen generation. To improve their performance, a detailed understanding of the individual steps is needed. Here, we study the interaction of a heteroleptic copper (I) photosensitizer with an iron catalyst by time-resolved spectroscopy and ab initio calculations. The catalyst leads to rather efficient quenching of the 3MLCT state of the copper complex, with a bimolecular rate being about three times smaller than the collision rate. Using control experiments with methyl viologen, an appearing absorption band is assigned to the oxidized copper complex demonstrating that an electron transfer from the sensitizer to the iron catalyst occurs and the system reacts along an oxidative pathway. However, only about 30% of the quenching events result in an electron transfer while the other 70% experience deactivation indicating that the photocatalytic performance might suffer from geminate recombination.
关键词： Solar hydrogen generation,Time-resolved spectroscopy,Ab initio calculations,Copper photosensitizers,Electron transfer
更新于2025-09-04 15:30:14