- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Conjugated donor-acceptor polymer photocatalysts with electron-output “tentacles” for efficient hydrogen evolution
摘要： The tunable structures and versatile properties for conjugated polymers (CPs) make them viable as a molecular platform for photocatalytic water splitting. Normally, structure design of polymer photocatalyst is focus on tuning its optical band structure or charge-separation ability, the importance of electron-output ability in photocatalytic process is always ignored. This study demonstrates a molecular engineering strategy by introducing an electron-output “tentacle” site, i.e. dibenzothiophene-S,S-dioxide (FSO) unit, into the polymer backbone to construct a series of donor-acceptor type conjugated polymer photocatalysts for efficient hydrogen evolution, which not only results in optimized light absorption ability and excellent exciton-separation, but also leads to the efficient electron-output ability. Detailed DFT calculations further theoretically confirm the vital role of FSO unit as an electron-output “tentacle” site.
关键词： Conjugated polymer,Electron-output “tentacles”,Artificial photosynthesis,Hydrogen evolution,Photocatalysis
更新于2025-09-23 15:23:52
-
Perovskite photocatalyst CsPbBr3-xIx with a bandgap funnel structure for H2 evolution under visible light
摘要： A simple and efficient light-assisted method is employed to prepare powder samples of all-inorganic mixed-perovskite CsPbBr3-xIx from CsPbBr3 by ion exchange in aqueous HBr/KI solution such that the concentration of I in a sample particle decreases on going from the surface to the interior. CsPbBr3-xIx/Pt, namely, CsPbBr3-xIx samples loaded with Pt nanoparticles, shows a high performance for the hydrogen evolution under visible-light irradiation in aqueous HBr solution saturated with CsPbBr3. The H2 evolution rate of the CsPbBr3-xIx/Pt powders (200 mg) is determined to be 224 μmol h-1, under 120 mW cm-2 visible-light (λ ≥ 420 nm) illumination. The CsPbBr3-xIx samples have a high stability, with no apparent decrease in the catalytic activity after 50 h of repeated H2 evolution experiments. The apparent quantum efficiency of CsPbBr3-xIx/Pt is determined to be 2.15% under the irradiation of 450 nm light.
关键词： photocatalysis,hydrogen evolution,bandgap funnel,all-inorganic perovskite,halide gradient
更新于2025-09-23 15:23:52
-
MgO/g-C3N4 nanocomposites as efficient water splitting photocatalysts under visible light irradiation
摘要： A series of MgO/g-C3N4 nanocomposites was prepared by calcination of the mixture of magnesium nitrate hexahydrate and g-C3N4, and applied as photocatalysts for hydrogen evolution from water splitting. The results demonstrate that the MgO/g-C3N4 nanocomposites can effectively harvest sunlight to produce hydrogen from water with higher photocatalytic efficiency than the bare g-C3N4. A high hydrogen evolution rate (HER) of 30.1 μmol h-1 was achieved under visible light for the MgO/g-C3N4 composite loaded with 1 wt% MgO, which is much higher than that of the bare g-C3N4 (5.76 μmol h-1). The enhanced photocatalytic activity of the MgO/g-C3N4 composite could be attributed to the formation of heterojunction between g-C3N4 and MgO that promotes the photo-induced charge carriers' transmission and separation.
关键词： photocatalysis,MgO/g-C3N4 nanocomposite,heterojunction,hydrogen evolution
更新于2025-09-23 15:23:52
-
Carbon Nanotube-Supported Cu <sub/>3</sub> P as High-Efficiency and Low-Cost Cocatalysts for Exceptional Semiconductor-Free Photocatalytic H <sub/>2</sub> Evolution
摘要： Developing an inexpensive and high-efficiency hydrogen-production cocatalyst to replace the noble metal Pt remains a big challenge in the fields of sustainable photocatalytic hydrogen evolution. Herein, we report the exploration of a high-efficient binary noble metal free Cu3P-CNT H2-evolution cocatalyst by direct high-temperature phosphatizing of Cu(OH)2-CNT. Impressively, combining the advantages of noble metal free Cu3P and carbon nanotube (CNT), the binary Cu3P-CNT cocatalysts show high-efficient photocatalytic H2 evolution in Eosin Y(EY)-contained semiconductor-free photocatalytic systems. The maximum visible-light H2-generation rate for promising EY-Cu3P-CNT systems was 17.22 mmolg-1h-1. The highest apparent quantum efficiency (AQE) could reach 10.23% at 500 nm. More importantly, we found that the separation of photogenerated electrons and holes in the Eosin Y, the efficiency of electron transfer from EY to the active edge sites of Cu3P, and the electrocatalytic H2-evolution activity of Cu3P, could be simultaneously boosted via readily adding the conductive CNT, thus achieving the significantly improved photocatalytic H2 evolution. This work provides a simple and facile strategy to design highly efficient semiconductor-free photocatalytic proton-reduction systems using high-activity transition metal phosphides (TMPs) and inexpensive carbon nanomaterials.
关键词： Photocatalytic Hydrogen Evolution,noble metal-free Cu3P Co-catalysts,Solar Fuel,Carbon nanotube (CNT),Dye sensitization
更新于2025-09-23 15:23:52
-
Highly efficient H2 production over NiCo2O4 decorated g-C3N4 by photocatalytic water reduction
摘要： Herein, ternary nickel cobalt oxide (NiCo2O4) was firstly employed to increase the photocatalytic water reduction ability of g-C3N4. 17.5wt%-NiCo2O4/g-C3N4 shows excellent water splitting performance with a H2 production rate of 5480 μmol·h-1·g-1, which is extremely better than that of Co3O4, NiO, Pt modified g-C3N4. The quantum efficiency of 17.5wt%-NiCo2O4/g-C3N4 can reach 4.5% under 400 (±7.5) nm light irradiation. The greatly increased activity of 17.5wt%-NiCo2O4/g-C3N4 can be attributed to the richer active sites and the superior electrical performance provided by co-existing nickel and cobalt ions with multivalent state. Moreover, the activity of composite almost shows no significant weaken even after 20 h irradiation. A Z-scheme route was put forwarded for H2 production over NiCo2O4/g-C3N4 instead of the traditional p-n junction based on our study.
关键词： NiCo2O4,bimetallic complex,photocatalysis,hydrogen evolution
更新于2025-09-23 15:23:52
-
Visible Light Driven Hydrogen Evolution by Molecular Nickel Catalysts with Time-Resolved Spectroscopic and DFT Insights
摘要： Hydrogen (H2) is a clean fuel that can potentially be a future solution for the storage of intermittent renewable energy. However, current H2 production is mainly dominated by the energy intensive steam reforming reaction, which consumes a fossil fuel, methane, and emits copious amounts of carbon dioxide as one of the byproducts. To address this challenge, we report a molecular catalyst that produces H2 from aqueous solutions, is composed of affordable, earth-abundant elements such as nickel, and has been incorporated into a system driven by visible light. Under optimized conditions, we observe a turnover number of 3880, among the best for photocatalytic H2 evolution with nickel complexes from water?methanol solutions. Through nanosecond transient absorption, electron paramagnetic resonance, and UV?vis spectroscopic measurements, and supported by density functional theory calculations, we report a detailed study of this photocatalytic H2 evolution cycle. We demonstrate that a one-electron reduced, predominantly ligand-centered, reactive Ni intermediate can be accessed under visible light irradiation using triethylamine as the sacrificial electron donor and reductive quencher of the initial photosensitizer excited state. In addition, the computational calculations suggest that the second coordination sphere ether arms can enhance the catalytic activity by promoting proton relay, similar to the mechanism among [FeFe] hydrogenases in nature. Our study can form the basis for future development of H2 evolution molecular catalysts that incorporate both ligand redox noninnocence and alternative second coordination sphere effects in artificial photosynthetic systems driven by visible light.
关键词： Proton relay,Second coordination sphere,DFT calculations,Time-resolved spectroscopy,Visible light photocatalysis,Hydrogen evolution,Molecular nickel catalysts
更新于2025-09-23 15:23:52
-
Fabrication of new metal-free materials for the hydrogen evolution reaction on base of the acridine derivatives immobilized on carbon materials
摘要： The process of adsorption on carbon material (Vulcan XC-72 (VU)) of organic heterocyclic compounds: acridine (I) and its derivatives 9-phenylacridine (II) and N-methyl-9-phenylacridium iodide (III) was studied in detail. Quantitative data on physical adsorption were obtained for all compounds. Based on the adsorption isotherms of Langmuir, the adsorption equilibrium constants K, the parameter A∞ and ΔG0 ad were calculated. It has been shown that the adsorption of compounds I and II is a structurally dependent process that depends on the nature and size of the functional substituents in the molecule, and the adsorption of compound III has a complex mechanism and partially proceeds through the stabilization stage by the functional groups present on the surface (-COOH, -COH, -OH). With the use of quantum chemical calculations, it has been established that the process of adsorption of compounds on the surface of a carbon materials having sections with a graphite-like structure is thermodynamically unprofitable because of the high difference in the energies of the adsorbent's boundary orbitals and the substrate. Using the cyclic voltammetry method, the electrochemical properties of organic compounds immobilized on the surface of a carbon material were studied.
关键词： Electocatalysis,Acridine derivatives,Immobilization,Adsorption,Carbon materials,Hydrogen evolution reaction
更新于2025-09-23 15:22:29
-
In-situ Platinum Plasmon Resonance Effect Prompt Titanium Dioxide Nanocube Photocatalytic Hydrogen Evolution
摘要： In-situ photodeposition Pt nanoparticles (Pt NPs) on TiO2 on account of the surface plasmonic resonance (SPR) effect and strong interaction of two components, which exhibits an elevated solar-driven photocatalytic hydrogen evolution performance. Herein, Pt-decorated TiO2 nanocube hierarchy structure (Pt-TNCB) was in-situ fabricated via a facile solvothermal synthesis and photodeposition strategy. The Pt-TNCB exhibits an excellent solar-driven photocatalytic hydrogen evolution rate (337.84 μmol h-1), which is about 37 times higher than that of TNCB (9.19 μmol h-1). Interestingly, its photocatalytic property is still superior to TNCB with post modification Pt (1 wt %) (208.11 μmol h-1). The introduction of Pt efficiently extends the photoresponse of composite material from UV to visible light region, simultaneously boost their solar-driven photocatalytic performance, which attribute to the porous structure, the subsize TNCB, the SPR effect of Pt NPs and strong interaction of two components. In fact, Pt NPs can enhance collective oscillations on delocalized electrons, which is conducive to capture electrons and hinder the recombination of photogenerated electron-hole pairs, leading to the longer lifetime of photogenerated charges. The fabrication of Pt-TNCB photocatalyst with SPR effect may provide a promising method to improve visible-light photocatalytic activities for traditional photocatalysts.
关键词： hydrogen evolution,titanium dioxide,surface plasmonic resonance,photodeposition,photocatalyst
更新于2025-09-23 15:22:29
-
Integrating non-precious-metal cocatalyst Ni3N with g-C3N4 for enhanced photocatalytic H2 production in water under visible-light irradiation
摘要： Photocatalytic H2 production via water splitting in a noble-metal-free photocatalytic system has attracted much attention in recent years. In this study, noble-metal-free Ni3N was used as an active cocatalyst to enhance the activity of g-C3N4 for photocatalytic H2 production under visible-light irradiation (λ > 420 nm). The characterization results indicated that Ni3N nanoparticles were successfully loaded onto the g-C3N4, which accelerated the separation and transfer of photogenerated electrons and resulted in enhanced photocatalytic H2 evolution under visible-light irradiation. The hydrogen evolution rate reached ~305.4 μmol h?1 g?1, which is about three times higher than that of pristine g-C3N4, and the apparent quantum yield (AQY) was ~0.45% at λ = 420 nm. Furthermore, the Ni3N/g-C3N4 photocatalyst showed no obvious decrease in the hydrogen production rate, even after five cycles under visible-light irradiation. Finally, a possible photocatalytic hydrogen evolution mechanism for the Ni3N/g-C3N4 system is proposed.
关键词： Hydrogen evolution,g-C3N4,Cocatalyst,Ni3N,Photocatalysis
更新于2025-09-23 15:22:29
-
Synthesis of non-noble metal nickel doped sulfide solid solution for improved photocatalytic performance
摘要： Bimetallic Sul?des, a series of versatile catalysts, are still hampered from putting into practical application due to the issue of the recombination of photogenerated charges. In this work, in order to enhance the light harvesting ability as well as ameliorate the separation and transportation of photo-induced charges at the same time, Ni ion was adopted to modify Zn0.5Cd0.5S catalyst. The subsequent photocatalytic water splitting tests showed that the H2 evolution rate over Ni doped Zn0.5Cd0.5S was 6 times higher than that achieved on the prestine Zn0.5Cd0.5S, indicating a signi?cant enhancement in catalytic activity. Furthermore, the selective oxidation of benzyl alcohol was also performed by the as-prepared catalysts under visible light irradiation. When 1% Ni ions were doped in Zn0.5Cd0.5S solid solution, the yield of product benzaldehyde was increased from 70% to 92%. The photoelectrochemical test suggests that the improved photocatalytic performance is presumably ascribed to the e?cient separation of photo-generated carriers. Additionally, DOS calculation con?rms the contribution of the improved light harvesting ability of Ni-doped Zn0.5Cd0.5S in the photocatalytic reaction. In all, this work presents that doping Ni into ZnS/CdS solid solution is a very useful technique to improve photocatalytic activity for two typical photocatalytic reactions-the H2 evolution and alcohol selective oxidation reaction.
关键词： Photocatalyst,Metal doping,Selective oxidation,Hydrogen evolution
更新于2025-09-23 15:22:29