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Carbon quantum dots/TiO2 nanosheets with dominant (001) facets for enhanced photocatalytic hydrogen evolution
摘要： Carbon quantum dots/TiO2 nanosheets with a majority of (001) facet (CQDs/TiO2-001) samples are successfully prepared via a facile method. Compared to TiO2-001 and CQDs/P25, the synthesized CQDs/TiO2-001 presents a remarkably higher photocatalytic activity for H2 evolution with a considerable stability. XRD, XPS, HRTEM, FESEM, FTIR, Photoluminescence (PL) spectroscopy, Fluorescence spectroscopy and UV–visible reflectance spectroscopy are adopted to investigate the morphology, structure and properties of synthesized CQDs/TiO2-001. The mechanism of the improved photocatalytic activity over CQDs/TiO2-001 is also investigated. The results show that the improved photocatalytic activity over CQDs/TiO2-001 can be attributed to the synergistic effects of TiO2-001 and CQDs: the highly exposed (001) facets of TiO2-001 promote the transportation of photogenerated electrons and the loading of CQDs restrains the recombination of electrons-holes on (001) facets. Meanwhile, the visible-light absorption is extended because the CQDs serve as a photosensitizer and sensitize TiO2-001 through the newly formed TieOeC bond between the CQDs and TiO2-001.
关键词： Carbon quantum dots,TiO2,Photocatalytic H2 evolution,(001) facet
更新于2025-11-21 11:01:37
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NiSe as an effective co-catalyst coupled with TiO2 for enhanced photocatalytic hydrogen evolution
摘要： Construction of semiconductor heterojunctions can effectively accelerate the separation of photo-induced charge carriers and thereby enhance photocatalytic activity. Here, NiSe was used as an effective co-catalyst to construct an active NiSe/TiO2 heterojunction for improving the photocatalytic H2 production of TiO2. The resultant 10%NiSe/TiO2 heterojunction exhibited 11 times higher photocatalytic H2-production activity than that of bare TiO2. The NiSe/TiO2 heterojunction and the photo-reduction of partial Ni2t to Ni0 notably accelerated the separation and transfer of photo-excited electron-hole pairs, and thus resulted in obvious improvement of H2-evolution activity. This work holds promise for the application of NiSe in photocatalysis as a high-efficiency photocatalytic cocatalyst.
关键词： NiSe/TiO2,Photoreduction,Heterojunction,Metal Ni0,Photocatalytic H2 evolution
更新于2025-11-14 17:04:02
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Intrinsic Au-decoration on anodic TiO2 nanotubes grown from metastable Ti–Au sputtered alloys—High density co-catalyst decoration enhances the photocatalytic H2 evolution
摘要： Recent work demonstrated that intrinsic Au nanoparticle decoration of TiO2 nanotube arrays (NTs) can be achieved by electrochemical anodization of Ti–Au alloy substrates. However, for a Ti–Au cast alloy produced by melt-alloying, the Au concentration cannot exceed the solubility limit of Au in Ti of 0.2 at.% – this sets constraints on the intrinsic Au nanoparticle loading on anodic TiO2 NTs. Here we explore “metastable” Ti–Au metal substrates that are produced by Ti and Au cosputtering and we establish Au concentrations that far exceed the solubility limit in cast Ti–Au alloys. We show the use of these “metastable” Ti–Au sputtered layers for the anodic formation of TiO2 NTs with a much higher density of Au nanoparticle loading than using classic alloys. Under optimized conditions (Au nanoparticle density) photocatalytic H2 production from such Au@TiO2 platforms provides a 15 times higher photocatalytic H2 evolution rate than the best rates achieved with conventional alloys.
关键词： Anodic TiO2 nanotube,Metastable Ti–Au alloy,Sputtering,Anodization,Photocatalytic H2 evolution
更新于2025-09-23 15:23:52
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Sulfur-doped porous graphitic carbon nitride heterojunction hybrids for enhanced photocatalytic H2 evolution
摘要： Graphitic carbon nitride (g-C3N4) is considered as an attractive, efficient and newly generated photocatalyst material owing to its distinct properties such as metal free, suitable band gap and high physicochemical stability. Nevertheless, the photocatalytic activity of pure g-C3N4 was limited by the fast recombination rate of photoinduced electron–hole pairs and relatively low specific surface area. In this study, we provide a new prospect to overcome the problem by using another suitable precursor urea-assisted copolymerization with thiourea which is expected to optimize the process of thermal condensation, inhibit agglomeration and improve the specific surface area; meanwhile, the formed isotype heterogeneous junction effectively inhibits charge carrier recombination. The formed g-C3N4 isotype heterojunction photocatalyst manifested significant improvement photocatalytic hydrogen production than the single and pure g-C3N4 sample. This significant enhanced photocatalytic performance is mainly ascribed to inhibited recombination, enriched active site and enlarged specific surface area.
关键词： porous graphitic carbon nitride,heterojunction hybrids,photocatalytic H2 evolution,Sulfur-doped
更新于2025-09-23 15:21:21
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Promoting Photocatalytic H <sub/>2</sub> Evolution on Organic–Inorganic Hybrid Perovskite Nanocrystals by Simultaneous Dual-Charge Transportation Modulation
摘要： Organic-inorganic hybrid perovskites have demonstrated great potential in solar cells fabrication due to the excellent optoelectronic properties. However, their success in solar cells has been hardly translated to producing solar fuels due to the instability issue and serious charge recombination at the nanoscale domain. Herein, we show for the first time that organic-inorganic hybrid perovskite methylammonium lead bromide (MAPbBr3) nanocrystals can be stabilized in aqueous HBr solution and achieve photocatalytic H2 production reaction under visible light. More impressively, by hybridizing MAPbBr3 with Pt/Ta2O5 and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) nanoparticles as electron and hole transporting motifs, respectively, drastically enhanced charge transportation on MAPbBr3 together with improved catalysis were achieved. As a consequence, the rate of photocatalytic hydrogen evolution on pristine MAPbBr3 was increased by ca. 52 times by introducing dual nanoscale charge transporting highways, achieving an apparent quantum efficiency of ca. 16.4% for H2 evolution at 420 nm.
关键词： Organic-inorganic hybrid perovskites,photocatalytic H2 evolution,visible light,charge transportation,MAPbBr3 nanocrystals
更新于2025-09-23 15:21:01
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Carbon coated-Cu nanoparticles as a cocatalyst of g-C3N4 for enhanced photocatalytic H2 evolution activity under visible-light irradiation
摘要： The photocatalytic H2 evolution is an important technology to solve the energy crisis. The hydrogen evolution rate of the g-C3N4 system in triethanolamine solution as sacrificial agent is obvious higher than in methanol solution. But up to now, most of the Cu nanoparticles as cocatalyst of g-C3N4 photocatalytic systems for hydrogen evolution are performed in methanol solution because Cu nanoparticles are unstable in triethanolamine solution. Here, carbon coated-Cu nanoparticles as cocatalyst of g-C3N4 composites (Cu@C/g-C3N4) were prepared by simple two-steps technology of annealing then grinding. The compositions, morphology and optical and photoelectrochemical (PEC) properties of the composites were characterized by means of physicochemical techniques. The prepared composition was used to generate hydrogen under visible light irradiation in triethanolamine solution. The results displayed that the hydrogen evolution rate of the optimal Cu@C/g-C3N4 was up to 265.1 μmol g-1 h-1 that is close to the activity of 0.5% Pt/g-C3N4, and after four repeated reactions, the photocatalytic activity decreased only by about 15%. The good photocatalytic activity and stability result from Cu nanoparticles increase the transfer efficiency of charge carriers by trapping the photogenerated electrons produced by g-C3N4 and the protective effect of carbon layer on Cu nanoparticles.
关键词： Cu nanoparticles,Visible-light,Graphite carbon nitride,Photocatalytic H2 evolution,Carbon coating layer
更新于2025-09-23 15:21:01
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Plasmonic Cocatalyst with Electric and Thermal Stimuli Boots Solar Hydrogen Evolution
摘要： Exploring low-cost and high-activity cocatalysts cooperated with semiconductors is a prerequisite to advance cost-efficient photocatalytic water splitting. Herein, nickel nanoparticles (NNPs) loaded on graphitic carbon nitride (CN) as unique non-noble metal cocatalysts with electric and thermal excitation upon surface plasmon for photocatalytic hydrogen (H2) evolution reaction (HER) are designed. The plasmonic NNPs not only endow highly active sites, steering hot electron extraction from excited CN toward HER against charge recombination, but also act as full-spectrum light-harvesting antennas enabling plasmon heating for kinetic acceleration. As a result, the optimized CN/NNP hybrid exhibits a significant increase in the H2-evolution rate up to 13.23 mmol g?1 h?1 with temperature up to 73 °C within 2 h, which far surpasses bare CN and even outperforms CN/Pt hybrid. This work describes the capacity of plasmonic cocatalysts to convert the supplementary photon flux into numerous stimuli, which provides new inspirations for designing photocatalytic systems for solar energy conversion.
关键词： electron transfer,photothermal effect,photocatalytic H2 evolution,metal plasmons,cocatalysts
更新于2025-09-23 15:19:57
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Controlled Growth and Bandstructure Properties of One Dimensional Cadmium Sulfide Nanorods for Visible Photocatalytic Hydrogen Evolution Reaction
摘要： One dimensional (1D) metal sulfide nanostructures are one of the most promising materials for photocatalytic water splitting reactions to produce hydrogen (H2). However, tuning the nanostructural, optical, electrical and chemical properties of metal sulfides is a challenging task for the fabrication of highly efficient photocatalysts. Herein, 1D CdS nanorods (NRs) were synthesized by a facile and low-cost solvothermal method, in which reaction time played a significant role for increasing the length of CdS NRs from 100 nm to several micrometers. It is confirmed that as the length of CdS NR increases, the visible photocatalytic H2 evolution activity also increases and the CdS NR sample obtained at 18 hr. reaction time exhibited the highest H2 evolution activity of 206.07 μmol.g-1.h-1. The higher H2 evolution activity is explained by the improved optical absorption properties, enhanced electronic bandstructure and decreased electron-hole recombination rate.
关键词： photocatalytic H2 evolution,bandstructure,CdS nanorods,electron-hole recombination,solvothermal synthesis
更新于2025-09-19 17:13:59
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Hybrid 0D/2D Ni2P quantum dot loaded TiO2(B) nanosheet photothermal catalysts for enhanced hydrogen evolution
摘要： The development of low cost, stable, robust photocatalysts to convert solar energy into hydrogen energy is an important challenge. Here, we describe a simple solvothermal method to successfully fabricate a catalyst with a hybrid 0D/2D Ni2P quantum dot/TiO2(B) nanosheet architecture. HRTEM shows that Ni2P quantum dots about 5 nm in size were dispersed on ultrathin TiO2(B) nanosheets. The optimum photocatalytic H2 evolution rate with 10 wt% Ni2P/TiO2(B) (3.966 mmol g?1 h?1), which was 15 times higher than pure TiO2(B) nanosheets. Significantly, the new catalyst shows high stability and reusability in multiply cycled H2 production runs for a 30 h period. The H2 production rate can be considerably increased furthered by using synergistic photothermal H2 evolution (20.129 mmol g?1 h?1 at 90 °C).
关键词： TiO2(B) nanosheets,Photocatalytic H2 evolution,Ni2P quantum dots,0D/2D architecture,Synergistic photothermal catalysis
更新于2025-09-11 14:15:04
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Facile synthesis of rod-like g-C3N4 by decorating Mo2C co-catalyst for enhanced visible-light photocatalytic activity
摘要： Designing and optimizing visible-light-driven photocatalyst with cost-efficiency and high performance is very imperative and highly challenging for photocatalytic hydrogen evolution reaction. Herein, g-C3N4/Mo2C hybrid photocatalyst with one dimensional (1D) heterostructure for highly enhanced photocatalytic H2 generation activity were obtained by a facile two step processing, in which Mo2C nanoparticles were highly dispersed on rod-like g-C3N4 surface. Attributed to the synergistic effect of 1D structure and Mo2C co-catalyst, the resultant g-C3N4/Mo2C sample exhibits an impressive visible-light photocatalytic H2 production rate of up to 507 μmol?h-1?g-1 and quantum efficiencies of 3.74% at 420 nm, which is 9.8 times higher than that of bulk g-C3N4, indicating that decorating Mo2C as co-catalysts on the surface of g-C3N4 leads to the improved visible light absorption, promoted charge separation and enhanced the following H2-evolution rate. Moreover, the mechanism for the photocatalytic activity enhancement was also discussed. This study provides a guide for researchers to design efficient g-C3N4-based hybrid photocatalysts with excellent stability and photocatalytic activity during the photoreaction process.
关键词： Photocatalytic H2 evolution,1D heterostructure,g-C3N4,Mo2C co-catalyst
更新于2025-09-10 09:29:36