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Quantum Yield Enhancement in Graphene Quantum Dots via Esterification with Benzyl Alcohol
摘要： The quantum yield of graphene quantum dots was enhanced by restriction of the rotation and vibration of surface functional groups on the edges of the graphene quantum dots via esterification with benzyl alcohol; this enhancement is crucial for the widespread application of graphene quantum dots in light-harvesting devices and optoelectronics. The obtained graphene quantum dots with highly graphene-stacked structures are understood to participate in π–π interactions with adjacent aromatic rings of the benzylic ester on the edges of the graphene quantum dots, thus impeding the nonradiative recombination process in graphene quantum dots. Furthermore, the crude graphene quantum dots were in a gel-like solid form and showed white luminescence under blue light illumination. Our results show the potential for improving the photophysical properties of nanomaterials, such as the quantum yield and band-gap energy for emission, by controlling the functional groups on the surface of graphene quantum dots through an organic modification approach.
关键词： Optoelectronics,Esterification,Quantum yield,Benzyl alcohol,Graphene quantum dots
更新于2025-11-19 16:46:39
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Visible-light-initiated one-pot clean synthesis of nitrone from nitrobenzene and benzyl alcohol over CdS photocatalyst
摘要： The controlled visible-light mediated conversion of nitroaromatics to versatile nitrogen-containing intermediates is of great significance but still remains a challenge. Herein, we report for the first time a facile visible-light-initiated one-pot strategy for clean and efficient synthesis of nitrone from nitrobenzene and benzyl alcohol. It integrates the controlled photocatalytic reduction of nitrobenzene to phenylhydroxylamine by photogenerated electrons with the selective photocatalytic oxidation of benzyl alcohol to benzaldehyde by photoinduced holes over a low-cost CdS photocatalyst with a suitable reduction capability, followed by spontaneous condensation of the as-formed hydroxylamine and aldehyde at ambient pressure and room temperature. Furthermore, by modulating cocatalyst and illumination time, for the conversion of the same reactants, the other two useful nitrogen-containing compounds, imine and secondary amine, were also successfully synthesized. The reaction mechanisms for flexible synthesis of the three target products are proposed.
关键词： One-pot strategy,Clean synthesis,Photocatalysis,Nitrobenzene and benzyl alcohol,Nitrone,Imine and secondary amine
更新于2025-09-23 15:23:52
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Realizing Synergistic Effect of Electronic Modulation and Nanostructure Engineering over Graphitic Carbon Nitride for Highly Efficient Visible-Light H2 Production Coupled with Benzyl Alcohol Oxidation
摘要： Photocatalytic H2 production based on g-C3N4 faces enormous challenging issues including limited visible-light absorption, poor separation and transfer abilities of photo-generated electron-hole pairs. Herein, we realize the synergistic effect of nanostructure engineering and electronic modulation with a supramolecular assembly mediated synthesis of heteroatom doped g-C3N4 hierarchical mesoporous spheres. The favorable doping site and possible effect on electronic structure are disclosed by DFT calculation with supporting experimental analysis. Impressively, S-doped g-C3N4 delivers a 13.2 times higher H2 production rate than bulk g-C3N4 under visible-light. More importantly, as the dual functional photocatalyst for H2 production and selective oxidation of benzyl alcohol, it can exhibit outstanding activity with a H2/benzaldehyde production rate of 3.76/3.87 μmol h-1, respectively. This work not only provide a new rationale for photocatalytic performance enhancement, but also shed new light on the highly efficient utilization of solar energy by coupling H2 generation with value added chemical production.
关键词： graphitic carbon nitride,hierarchical mesoporous spheres,DFT calculation,benzyl alcohol oxidation,photocatalytic hydrogen production
更新于2025-09-23 15:19:57
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Unraveling the impact of the Pd nanoparticle@BiVO <sub/>4</sub> /S-CN heterostructure on the photo-physical & opto-electronic properties for enhanced catalytic activity in water splitting and one-pot three-step tandem reaction
摘要： Pd nanoparticles embedded SBVCN-37 heterostructure photocatalyst is synthesized and employed in the water splitting reaction and for the synthesis of imines via one-pot tandem reaction involving photocatalytic reduction of nitrobenzene, oxidation of benzyl alcohol, followed by condensation reaction between them. Embedded Pd nanoparticles (mean diameter ~ 5-7 nm) act as an electron mediator and enhance the catalytic activity during oxidation and reduction reactions. Experimental results confirm that the light induced holes owing to its favourable redox potential oxidize N2H4 to N2 and liberate H+ ions that subsequently react with photogenerated electrons and facilitate the nitrobenzene reduction. The obtained quantum yield for benzyl alcohol oxidation and nitrobenzene reduction are calculated to be (2.08 %) and (6.53 %) at λ = 420 nm light illumination. The obtained apparent quantum yields for OER and HER are calculated to be 10.22 % and 12.72 % at 420 nm indicating the excellent potentiality of the presently investigated photocatalyst for solar fuel production. Photoelectrochemical (PEC) and time resolved & steady state photoluminescence measurements reveal that an optimum amount of Pd nanoparticles over SBVCN-37 is the crucial factor for achieving the highest photocurrent response, the lowest charge transfer resistance, and the efficient carrier’s mobility alteration leading to a prominent catalytic activity. Further, Mott-Schottky (M-S) analysis confirms that the deposition of Pd nanoparticles effectively reduces the over-potential and fine-tunes the band edge potential required for HER and OER reactions, independently.
关键词： Tandem Reaction,BiVO4,Benzyl Alcohol Oxidation,Apparent Quantum Yield,Nitrobenzene Reduction,g-C3N4,Photocatalytic H2 and O2 Production
更新于2025-09-19 17:15:36
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Photo-induced generation of size controlled Au nanoparticles on pure siliceous ordered mesoporous silica for catalytic applications
摘要： A versatile in situ photochemical reduction approach was used to generate a composite of gold nanoparticles and pure siliceous SBA-15 silica support with regular mesopores. The mesoporous silica support was first synthesized and, after calcination, was suspended in a solution of gold bromide (EtOH or H2O) containing a free radical generator activated by UV irradiation and used for the photochemical reduction of gold precursor. The influence of gold precursor concentration, light intensity and nature of the solvents on the formation and properties of gold nanoparticles (size, dispersion, stability) on the mesoporous SBA-15 support have been studied with the aim of optimizing the dispersion of the gold nanoparticles in the mesoporous network and their chemical stability. The catalytic activity of the resulting AuNPs@SBA-15 nanocomposite was successfully evaluated for the oxidation of benzyl alcohol reaction in liquid-phase.
关键词： Benzyl alcohol,Photoreduction,Gold nanoparticles,Mesoporous silica,SBA-15,Oxidation
更新于2025-09-12 10:27:22
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A tunable synthesis of either benzaldehyde or benzoic acid through blue-violet LED irradiation using TBATB
摘要： In this paper, a highly efficient, metal-free, and homogeneous photooxidative-desilylation of tert-butyldimethylsilyl ethers (TBDMS) in the presence of tetrabutylammonium tribromide (TBATB) under irradiation of visible light was reported. The light source: blue (460 nm) and violet (400 nm) LED, can control selective oxidation to aldehyde or carboxylic acid.
关键词： tetrabutylamonium tribromide,benzyl alcohol,metal-free,tunable synthesis,oxidative-desilylation,visible light photocatalyst
更新于2025-09-12 10:27:22
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Ultrasound assisted ZnO coating in a microflow based photoreactor for selective oxidation of benzyl alcohol to benzaldehyde
摘要： Heterogeneous photocatalysis in a microflow system for generation of value added chemicals is a novel green chemistry approach requiring the understanding of photocatalysis, microfluidics and reactor design. Research on the development of a low energy and environmentally friendly based photo-microreactor system for photocatalysis is yet to be explored. Commercial ZnO nanoparticles were deposited in the inner wall of a fluoropolymer using a low energy ultrasound bath under mild conditions and later used for selective conversion of aromatic alcohols to aldehydes. The deposition of the nanoparticles on the fluoropolymer is mainly attributed to the physical changes taking place inside the microtubes under the effect of ultrasound.
关键词： Benzyl alcohol,Microflow photoreactor,Ultrasound,Benzaldehyde,ZnO coating,Selective oxidation,Green Chemistry
更新于2025-09-04 15:30:14