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MOF-templated core-shell Co(II/III)@ZnO hexagonal prisms for selective oxidation of vanillyl alcohol
摘要： This work provides a facile strategy to prepare core-shell structured catalysts with MOF-templated metal active species embedded carbon matrix core and a functional metal oxide shell in a controllable way. The procedure features with the facile introduction of functional shell metal oxide and delivery of MOF morphology. Co(II/Ⅲ)@ZnO hexagonal prisms are fabricated with this procedure and ZIF-67 as the template. When being used in the selective oxidation of vanillyl alcohol to produce vanillin, ZnO shell plays an important role by faciliating redox of Co3+/Co2+ for promoting vanillyl alcohol oxidation to vanillin and protecting the Co species against leaching into the reaction system. Co(II/Ⅲ)@ZnO exhibits a conversion of 20% with a selectivity of 80% after a 2 h reaction and shows stability after 3 catalytic cycles.
关键词： selective oxidation,vanillin,MOF-templated,ZnO,core-shell
更新于2025-11-14 17:03:37
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Metal Sulfide Photocatalysis: Visible-Light-Induced Organic Transformations
摘要： Transition-metal sulfides belong to an important subgroup of semiconductor photocatalysts that could promote a variety of valuable redox reactions under mild conditions. One notable merit of metal sulfides is their relatively smaller bandgaps than metal oxides, which in turn make sure that many of them can directly utilize visible light. Historically, the deployment of metal sulfides for visible-light-induced organic transformations took place shortly after the genesis of the research field of heterogeneous photocatalysis. In this review, we primarily focus on recent state-of-the-art advancements of metal sulfide photocatalysis aimed at visible-light-induced selective organic transformations. Interests in this specific branch of photocatalysis have been rekindled due to the new methods for materials synthesis; the pursuit of new mechanisms; or the integration of metal sulfides with metal oxides, metal nanoparticles or other emerging materials. Thus we categorize them into four sections according to the different strategies in developing novel or more efficient organic processes. Binary and ternary metal sulfides, usually associated with new materials synthesis and mechanistic insights, can be used directly for visible-light-induced organic transformations. This is the basis of other further developments and will be introduced firstly. Next, the cooperation between metal sulfides and metal oxides or metal nanoparticles can be conducive to many photocatalytic systems. These developments will be discussed in the next two ensuing sections. Furthermore, the integration of metal sulfides with recent developed emerging materials such as metal-organic frameworks (MOFs), graphene and graphitic carbon nitride (g-C3N4) would be discussed in another section to highlight the importance of merging metal sulfides with these materials. We attempt to keep an impartial panorama of these four distinctive sections even though the phases of development are quite different among sections, leaving plenty of room for the future expansion of this burgeoning area.
关键词： Metal Sulfide,Selective Oxidation,Photocatalysis,Visible Light,Selective Reduction
更新于2025-09-23 15:23:52
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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
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Photocatalysts for Hydrogen Evolution Coupled with Production of Valuea??Added Chemicals
摘要： The conversion of water into clean hydrogen fuel using renewable solar energy can potentially be used to address global energy and environmental issues. However, conventional photocatalytic H2 evolution from water splitting has low efficiency and poor stability. Hole scavengers are therefore added to boost separation efficiency of photoexcited electron–hole pairs and improve stability by consuming the strongly oxidative photoexcited holes. The drawbacks of this approach are increased cost and production of waste. Recently, researchers have reported the use of abundantly available hole scavengers, including biomass, biomass-derived intermediates, plastic wastes, and a range of alcohols for H2 evolution, coupled with value-added chemicals production using semiconductor-based photocatalysts. It is timely, therefore, to comprehensively summarize the properties, performances, and mechanisms of these photocatalysts, and critically review recent advances, challenges, and opportunities in this emerging area. Herein, this paper: 1) outlines reaction mechanisms of photocatalysts for H2 evolution coupled with selective oxidation, C–H activation and C–C coupling, together with nonselective oxidation, using hole-scavengers; 2) introduces equations to compute conversion/selectivity of selective oxidation; 3) summarizes and critically compares recently reported photocatalysts with particular emphasis on correlation between physicochemical characteristics and performances, together with photocatalytic mechanisms, and; 4) appraises current advances and challenges.
关键词： C–C coupling,C–H activation,selective oxidation,photocatalysis,hydrogen evolution
更新于2025-09-19 17:13:59
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Selective oxidation of the surface layer of bilayer WSe <sub/>2</sub> by laser heating
摘要： WSe2 films have several anisotropies between the in-plane and out-of-plane directions, which affects their responses to external operation. Guided by the anisotropies, we provide adequate heat propagation to oxidize selectively the surface layer of bilayer WSe2 and characterized the structure of monolayer WSe2 covered with an oxidized layer by optical and atomic force microscopy, Raman spectroscopy and photoluminescence measurements. Furthermore, we found indications that laser treatments of monolayer WSe2 covered with an oxidized layer have possibility to cause photoactivated oxidation. Our observations suggest clues to understand low-dimensional oxidation behaviours.
关键词： anisotropy,laser heating,WSe2,selective oxidation,photoluminescence
更新于2025-09-12 10:27:22
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Hybridizing engineering strategy of non-lacunary (nBu4N)4W10O32 by carbon quantum dot with remarkably enhanced visible-light-catalytic oxidation performance
摘要： This paper discloses an e?cient strategy for the preparation of carbon quantum dot (CQD)- hybridized (nBu4N)4W10O32 (TBADT). A key step in this strategy is to hydrothermally treat CQD with TBABr solution to form the TBA+ micelle-encapsulated CQD, which acts as a cationized hybridizer to combine with the W10O32 anion to yield the target catalyst. XPS, UV–vis, PL and CV characterizations indicated that CQD hybridizer plays unique roles in improving the structural stability, redox capacity and visible light response of TBADT, especially in enhancing the stability of its photo-excited state. In the visible light-triggered selective oxidation of cyclohexane, toluene, ethylbenzene and benzyl alcohol with dioxygens in acetonitrile, the optimized hybrid containing 3% CQD shows much higher photo-catalytic activity than pure TBADT, a?ording ca. 21.7% conversion and 84.8% cyclohexanone selectivity in cyclohexane photo-oxidation, Additionally, the additive 2 M HCl further enhances the above hybridization e?ects, thereby signi?cantly promoting the current photo-catalytic oxidations.
关键词： Selective oxidation of organic compounds,Hybridizing molecular engineering,Decatungstates,Molecular oxygen,Carbon quantum dot,Visible-light-catalysis
更新于2025-09-12 10:27:22
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Ag-Pd nanoparticles prepared by laser ablation for selective oxidation of propylene glycol to lactic acid
摘要： Silver/palladium composite nanoparticles (NPs) obtained by pulsed laser ablation in liquid (PLAL) technique catalyze oxidation of propylene glycol (PG) to lactic acid (LA) in alkaline media. The PLAL technique allows obtaining silver/palladium NPs with different silver/palladium molar ratio. Addition of palladium increases PG conversion (up to 52%) and LA selectivity (up to 88%). The reaction temperature and silver/palladium molar ratio strongly affects the catalytic activity of the silver/palladium composite NPs.
关键词： lactic acid,laser ablation,propylene glycol,Ag-Pd nanoparticles,selective oxidation
更新于2025-09-12 10:27:22
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Catalyst-Free Selective Oxidation of Diverse Olefins to Carbonyls in High Yield Enabled by Light under Mild Conditions
摘要： The selective oxidation of ole?ns, in particular, aromatic ole?ns to carbonyls, is of signi?cance in organic synthesis. In general, stoichiometric toxic oxidants or a high-cost catalyst is required. Herein we report a novel and practical light-enabled protocol for the synthesis of carbonlys in high yield through a catalyst-free oxidation of ole?ns using H2O2 as a clean oxidant. A broad scope of carbonyls can be synthesized in high yield, and no catalyst or toxic oxidant is required.
关键词： light-enabled,ole?ns,carbonyls,selective oxidation,H2O2,catalyst-free
更新于2025-09-11 14:15:04
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Highly Selective Oxidation of Glycerol over Bi/Bi3.64Mo0.36O6.55 Heterostructure: Dual Reaction Pathways Induced by Photogenerated 1O2 and Holes
摘要： Selective oxidation of glycerol to produce aimed high-value added products is of great importance in chemical industry. Photocatalytic oxidation provides a promising and green strategy for selective glycerol oxidation. In this work, we develop a Bi/Bi3.64Mo0.36O6.55 heterostructure via a facile solvothermal method for the selective oxidation glycerol to 1, 3-dihydroxyacetone (DHA) in water under visible light irradiation. The excellent performance in activity and selectivity of Bi/Bi3.64Mo0.36O6.55 heterostructure for DHA production is attributed to a dual-pathway photocatalytic reaction process. The mass production 1O2 ascribed to the reduced energy gap (ΔEST), the enhanced spin-orbit coupling (SOC) and the presence of oxygen vacancy is beneficial for the selective oxidation of glycerol to DHA. Simultaneously, the metallic bismuth in the heterostructure promotes the separation of photogenerated holes with efficient redox potential and facilitates the binding bismuth with ortho-hydroxyl in glycerol, thus enhancing the yield and selectivity of DHA production. This work provides a novel strategy and thorough understanding of the development of highly efficient bismuth-based photocatalyst for selective oxidation in organic reactions.
关键词： Photogenerated hole,Bi/Bi3.64Mo0.36O6.55,Glycerol,1O2,Selective oxidation
更新于2025-09-09 09:28:46
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C(sp <sup>3</sup> )-H Bond Activation by Perovskite Solar Photocatalyst Cell
摘要： Inspired by the efficient perovskite solar cells, we developed a three-component hybrid perovskite-based solar photocatalyst cell - NiOx/ FAPbBr3/TiO2 - for C(sp3)-H bonds activation with high selectivity (~90%) and high conversion rates (3800 μmol g-1 h-1) under ambient conditions. Time-resolved spectroscopy on our photocatalytic cell reveals efficient exciton dissociation and charge separation, where TiO2 and NiOx serve respectively as the electron and hole transporting layers. The photo-generated charge carriers, injected into TiO2 and NiOx drive the challenging C-H activation reaction via the synergetic effects of their band alignment relative to FAPbBr3. The reaction pathway is investigated by controlling the free radical formation and we find that C-H activation is mainly triggered by hole oxidation. Besides aromatic alkanes, also C(sp3)-H bond in cycloalkanes can selectively be oxidised. This work demonstrates a generic strategy for engineering high-performance photocatalysts based on the perovskite solar cell concept.
关键词： photocatalysis,perovskite solar cells,charge separation,C(sp3)-H bond activation,selective oxidation
更新于2025-09-09 09:28:46