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Black phosphorous sensitized TiO <sub/>2</sub> mesocrystals photocatalyst for hydrogen evolution with visible and near-infrared light irradiation
摘要： Wide absorption from ultraviolet (UV) to near-infrared (NIR) region and enhanced charge separation are two main requirements for promising semiconductor photocatalysts. Here, we studied visible-NIR driven photocatalytic hydrogen evolution over black phosphorus nanosheets/TiO2 mesocrystals loaded with Pt heterostructure (BP NS/ Pt (3 wt%)/TMC TMC). BP NS/Pt (3 wt%)/TMC can harvest photons from UV to NIR and simultaneously has enhanced charge separation to increase the generation of electrons for photocatalytic reduction of water. BP NS/Pt (3 wt%)/TMC exhibited photocatalytic H2 evolution rates of 1.9 and 0.41 μmol h-1 under visible (λ> 420 nm (420-1800 nm)) and NIR (λ> 780 nm (780-1800 nm) irradiation, respectively, compared with 0.3 and 0.10 μmol h-1 for BP NS/Pt (3 wt%)/P25. Moreover, a comparative study was made to examine the effect of thickness of BP NS on the photocatalytic H2 evolution. Femtosecond time-resolved diffused reflectance spectroscopy (fs-TRDRS) was integrated together with photoelectrochemical measurement to shed the light on the importance of charge transfer and separation, confirming that decreasing the thickness of BP NS enhances electron injection from BP NS to TMC to increase the photocatalytic activity.
关键词： hydrogen evolution,Black phosphorus,visible-light photocatalyst,charge carriers dynamics,TiO2 mesocrystals,femtosecond time-resolved diffuse reflectance
更新于2025-11-19 16:51:07
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Thiourea-assisted coating of dispersed copper electrocatalysts on Si photocathodes for solar hydrogen production
摘要： Photoelectrochemical water splitting can convert solar energy into clean hydrogen energy for storage. It is desirable to explore non-precious electrocatalysts for practical applications of a photoelectrode in a large scale. Here, we developed a facile spin-coating and in-situ photoelectrochemical reduction method to prepare a dispersed Cu electrocatalyst on a Si photocathode, which improves the performance remarkably. We find that thiourea in the precursor solution for spin-coating plays an important role in obtaining dispersed Cu particles on the surface of a Si photoelectrode. With thiourea in the precursor, the Cu/Si photocathode shows higher performance than the one without thiourea. Moreover, the Cu/Si photocathode also indicates good stability after 16 h illumination.
关键词： In-situ photoelectrochemical reduction,Cu electrocatalyst,Thiourea,Hydrogen evolution reaction
更新于2025-11-19 16:51:07
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A comparative study on photocatalytic hydrogen evolution activity of synthesis methods of CDs/ZnIn2S4 photocatalysts
摘要： The introduction of carbon materials in photocatalytic systems can significantly enhance the photocatalytic hydrogen evolution activity. Here, we proposed and fabricated carbon nanodots/ZnIn2S4 (CDs/ZIS) samples via three methods. The morphology, chemical elements and valence, and photoelectric properties of CDs/ZIS samples were systematically characterized by SEM, TEM, XPS, UV and PL. The photocatalytic H2 production experiments indicate that the photocatalytic performance of all CDs/ZIS samples has been significantly improved, which could be attributed to the fact that serving as an excellent electron acceptor, CDs can accelerate the separation efficiency of photogenerated electrons and holes. The samples prepared via one-pot hydrothermal method exhibit the optimal photocatalytic activity and the corresponding H2 production rate of 4.15 mmol g?1 h?1 under visible light irradiation (λ > 420 nm), which is about 2.92 times higher than pure ZIS. Our work presented the influence of synthetic method on photoelectric performance and photocatalytic activity of CDs/ZIS nanocomposites, and provided a reliable idea for improving the photocatalytic performance of photocatalyst toward practical applications.
关键词： Synthesis methods,ZnIn2S4,Photocatalytic hydrogen evolution,Carbon dots
更新于2025-11-14 15:29:11
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Stable Hybrid Perovskite MAPb(I1?Br )3 for Photocatalytic Hydrogen Evolution
摘要： Hybrid organic-inorganic perovskites have been pursuing for solar/visible-driven H2 evolution from hydrohalic acid (HX) splitting, but their inherent structural stability and performance are still challenging. Herein, we report on a stable hybrid perovskite MAPb(I1?xBrx)3 (x = 0 – 0.20) obtained by one-pot crystallization in a mixed halide parent solution and its implementation as a newcomer photocatalyst for H2 evolution in aqueous HX solution. MAPb(I1?xBrx)3 is demonstrated to be a superior visible-light-driven photocatalyst for H2 evolution in aqueous HI/HBr solution with no Pt as a cocatalyst. An optimized MAPb(I1?xBrx)3 (x = 0.10) shows a highest H2 evolution rate of 1471 μmol h?1 g?1 under visible light (λ ≥ 420 nm) illumination, which is ~ 40 times higher than that of pure MAPbI3, and the dual-halide perovskite is rather stable showing no obvious decrease in the photocatalytic activity over 60 runs (252 h). The perovskite inherent structural stability is further evidenced by XRD, UV-vis spectra and EDS elemental mapping of MAPb(I1?xBrx)3 measured after cycled photocatalytic reaction. The solar HI splitting efficiency of MAPb(I1?xBrx)3 (x = 0.10) is determined as 1.42%. The mechanism behind photocatalytic H2 evolution enhancement is elucidated by the experimental and computational methods.
关键词： photocatalyst,MAPb(I1?xBrx)3,hydrogen evolution,perovskite,visible light
更新于2025-11-14 15:28:36
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Construction of dual defect mediated Z-scheme photocatalysts for enhanced photocatalytic hydrogen evolution
摘要： The construction of Z-scheme system is a promising approach for photocatalytic hydrogen evolution (PHE). In this study, we fabricated a direct Z-scheme system consisting of defect-rich g-C3N4 nanosheets (DR-CNNS) crumpled nanosheets with defect-rich TiO2 (DR-TiO2) nanoparticles via a dual defective strategy. The optimized dual-defective rich TiO2/CNNS composite showed a superior PHE rate of ?651.79 μmol/h with a turnover frequency of ?419.3 h?1 as well as high stability and recyclability, which presented the highest value in single defective TiO2 or g-C3N4-based photocatalysts families reported previously. Furthermore, this protocol could also be extended to synthesize other dual defective g-C3N4/oxides (ZnO, SnO2, etc.) heterostructures. The improved photocatalytic performances could be ascribed to the following aspects: (1) rich dual defect, narrowing the band gap and providing more reactive sites for PHE; (2) intimate interface, facilitating interfacial migration and utilization of photogenerated charges; (3) Z-scheme structure, accelerating photogenerated electron-hole pair separation and thus leading to more e?cient PHE. Our work highlights the critical role of defects in construction of Z-scheme system and provides the possibility of utilizing dual defective g-C3N4-based systems for other photocatalytic applications including CO2 reduction and water puri?cation.
关键词： Photocatalytic hydrogen evolution,Dual defect,Oxides/g-C3N4,Heterojunction,Direct Z-scheme
更新于2025-11-14 15:27:09
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Cadmium sulfide nanostructures: Influence of morphology on the photocatalytic degradation of erioglaucine and hydrogen generation
摘要： Size and shape of inorganic materials are known to have great effects on their physical and chemical properties. Here, for the first time we report the visible light driven photocatalytic degradation of erioglaucine – a stable organic dye molecule in the presence of chemically synthesized nanoscale CdS with 1D (nanorods), 2D (nanosheets) and 3D (hierarchical) morphology. Visible light driven photocatalytic degradation efficiency of both 1D and 3D CdS in the removal of erioglaucine are identical. Surprisingly, with 5 min of sonication, the highly crystalline 3D CdS stacked with many thin nanowires containing numerous active surface sites exhibited four-fold enhanced photodegradation efficiency in comparison to 1D and 2D CdS. Scavenger studies revealed that electrons and superoxide radicals are primary reactive species involved in the photodegradation of erioglaucine, while cyclic photodegradation studies revealed the good stability of 3D CdS against photocorrosion. Further, the photocatalytic hydrogen evolution studies also revealed the excellent activity of 3D CdS in comparison to 1D and 2D CdS. Thus, we find that the morphology indeed influences the photocatalytic activity. These results reveal that 3D CdS nanostructures investigated in the present work are efficient photocatalysts that could be fine-tuned for both environmental remediation and hydrogen generation applications.
关键词： erioglaucine,nanostructures,photocatalysis,hydrogen evolution,Cadmium sulfide
更新于2025-11-14 14:48:53
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Surface-to-volume ratio drives photoelelectron injection from nanoscale gold into electrolyte
摘要： Hot charge carriers from plasmonic nanomaterials currently receive increased attention due to their promising potential in important applications such as solar water splitting. While a number of important contributions were made on plasmonic charge carrier generation and their transfer into the metal’s surrounding in the last decades, the local origin of those carriers is still unclear. With our study employing a nanoscaled bicontinous network of nanoporous gold, we take a comprehensive look at both subtopics in one approach and give unprecedented insights into the physical mechanisms controlling the broadband optical absorption and the generation and injection of hot electrons into an adjacent electrolyte where they enhance electrocatalytic hydrogen evolution. This absorption behavior is very different from the well-known localized surface plasmon resonance effects observed in metallic nanoparticles. For small ligament sizes the plasmon decay in our network is strongly enhanced via surface collisions of electrons. These surface collisions are responsible for the energy transfer to the carriers, thus, the creation of hot electrons from a broad spectrum of photon energies. As we reduce the gold ligament sizes below 30 nm, we demonstrate an occurring transition from absorption that is purely exciting 5d-electrons from deep below the Fermi level to an absorption which significantly excites “free” 6sp-electrons to be emitted. We differentiate these processes via assessing the internal quantum efficiency of the gold network photoelectrode as a function of the feature size providing a size-dependent understanding of the hot electron generation and injection processes in nanoscale plasmonic systems. We demonstrate that the surface effect - compared to the volume effect – becomes dominant and leads to significantly improved efficiencies. The most important fact to recognize is that in the surface photoeffect presented here, absorption and electron transfer are both part of the same quantum mechanical event.
关键词： Hot electron,Photoemission,Water splitting,Hydrogen evolution,Carrier injection,Surface damping,Nanoporous Au
更新于2025-10-22 19:40:53
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Zinc ions modified InP quantum dots for enhanced photocatalytic hydrogen evolution from hydrogen sulfide
摘要： Through direct addition of inorganic zinc ions into the solution of indium phosphide quantum dots (InP QDs) at ambient environment, we here present a facile but effective method to modify InP QDs for photocatalytic hydrogen evolution from hydrogen sulfide (H2S). X-ray diffraction patterns and transmission electron microscopic images demonstrate that zinc ions have no significant influence on the crystal structure and morphology of InP QDs, while X-ray photoemission spectra and UV–Vis diffuse and reflectance spectra indicate that zinc ions mainly adsorbed on the surface of InP QDs. Photocatalytic results show the average hydrogen evolution rate has been enhanced to 2.9 times after modification and H2S has indeed involves in the hydrogen evolution process. Steady-state and transient photoluminescence spectra prove that zinc ions could effectively eliminate the surface traps on InP QDs, which is crucial to suppress the recombination of charge carriers. In addition, the electrostatic interaction between zinc ions and the surface sulfide from InP QDs could mitigate the repulsion between QDs and sulfide/hydrosulfide, which may promote the surface oxidative reaction during photocatalysis. This work avoids the traditional harsh and complicated operations required for surface passivation of QDs, which offers a convenient way for optimization of QDs in photocatalysis.
关键词： Hydrogen sulfide,Photocatalytic hydrogen evolution,InP quantum dots,Surface modification
更新于2025-10-22 19:38:57
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A heterobimetallic Au(III)?Pt(II) photocatalyst for water reduction to hydrogen
摘要： A supramolecular complex, [Au(C^N^C)(C≡CC6H4C≡C)Pt(terpy)]+, has been synthesized as a photocatalyst for water reduction. This compound consists of a cyclometalated alkyngold(III) photosensitizer and a platinum(II) terpyridine complex bridged through a central phenylethynyl group.
关键词： heterobimetallic system,hydrogen evolution,photocatalyst
更新于2025-09-23 15:23:52
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Synthesis of a MoS <i> <sub/>x</sub></i> -O-PtO <i> <sub/>x</sub></i> Electrocatalyst with High Hydrogen Evolution Activity Using a Sacrificial Counter-Electrode
摘要： Water splitting is considered to be a very promising alternative to greenly produce hydrogen, and the key to optimizing this process is the development of suitable electrocatalysts. Here, a sacrificial-counter-electrode method to synthesize a MoSx/carbon nanotubes/Pt catalyst (0.55 wt% Pt loading) is developed, which exhibits a low overpotential of 25 mV at a current density of 10 mA cm?2, a low Tafel slope of 27 mV dec?1, and excellent stability under acidic conditions. The theory calculations and experimental results confirm the high hydrogen evolution activity that is likely due to the fact that the S atoms in MoSx can be substituted with O atoms during a potential cycling process when using Pt as a counter-electrode, where the O atoms act as bridges between the catalytic PtOx particles and the MoSx support to generate a MoSx–O–PtOx structure, allowing the Pt atoms to donate more electrons thus facilitating the hydrogen evolution reaction process.
关键词： sacrificial-counter-electrodes,O substitution,MoSx,hydrogen evolution reaction,PtOx
更新于2025-09-23 15:23:52