02320nas a2200229   4500008004100000022001400041245016200055210006900217260000900286300001600295490000600311520149100317100001901808700002101827700002101848700001901869700002101888700001801909700001901927700002201946856012201968       2020                        eng d  a2050-748800aWavelength dependent luminescence decay kinetics in `quantum-confined' g-C(3)N(4)nanosheets exhibiting high photocatalytic efficiency upon plasmonic coupling0 aWavelength dependent luminescence decay kinetics in quantumconfi  cOCT   a20581-205920 v83 a<p>Serendipitous observations offer newer insights into materials properties. Here we describe g-C(3)N(4)nanosheets exhibiting remarkably blue-shifted photoluminescence within the 390-580 nm range centred at 425 nm which matches more closely with its `quantum-dots', and yet is excitation-wavelength independent. Moreover, surprisingly, the luminescence decay becomes increasingly slow at higher emission wavelengths, by up to 10 times. The nanosheets absorb only a fraction of visible-light. To improve this, when we designed a nanocomposite of g-C(3)N(4)and Au nanoparticles (NPs), it retained the PL characteristics and also exhibited excellent light-harvesting and photocatalytic efficiency for benzylamine (BA) oxidation. The surface plasmon resonance of the Au NPs is responsible for the high visible-light response and assisting the reaction by the `hot-electron' injection mechanism, while an uncharacteristic, pronounced co-catalytic effect by them further improves the efficiency. The conversion is 98% with &gt;99% selectivity over 1.5 h of natural sunlight and open-air, probably the highest efficiency for BA photo-oxidation reactions. Even though such a dual role by plasmonic NPs has remained unscrutinized, we argue that the charge-transfer processes for the `hot-carrier' injection and co-catalytic events are well-separated in time due to a much slower photon incident frequency on a catalyst particle, enabling both to occur simultaneously in the same particle.</p>
1 aMondal, Sanjit1 aSahoo, Lipipuspa1 aVaishnav, Yuvraj1 aMishra, Samita1 aRoy, Raj, Sekhar1 aVinod, C., P.1 aDe, Arijit, K.1 aGautam, Ujjal, K.  uhttps://library.ncl.res.in/content/wavelength-dependent-luminescence-decay-kinetics-quantum-confined-g-c3n4nanosheets02070nas a2200253   4500008004100000022001400041245011500055210006900170260000800239490000700247520117600254653003201430653002301462653002101485653003201506653002301538100001901561700002101580700001901601700002101620700003601641700001801677856012101695       2024                        eng d  a2199-692X00aEnhancing the Catalytic Activity of Pd Nanocrystals towards Suzuki Cross-Coupling by g-C3N4 Photosensitization0 aEnhancing the Catalytic Activity of Pd Nanocrystals towards Suzu  cJAN0 v103 a<p>Developing renewable means of activating molecules over traditional catalysts for C-C bond formation is desirable for industrial applications. Herein, we report a strategy to improve the efficiency of Pd nanoparticles (NPs) for the Suzuki cross-coupling reactions by visible-light irradiation using g-C3N4 nanosheets (NSs) as photosensitizer. Pd NPs mounted on g-C3N4 become electron-rich under visible-light due to generation of excited electrons in g-C3N4 and thereby accelerate the rate-determining step. Remarkable photocatalytic activity was accomplished utilizing Pd/g-C3N4 for the Suzuki cross-coupling reaction in environmentally benign aqueous settings under room temperature conditions. The activity remarkably improves (similar to 2.5 times) upon light irradiation, yielding one of the highest known turnover frequencies (TOF) of 1858 h(-1) and confirming the photosensitizer role of g-C3N4. The TOF for coupling of aryl bromides is also significantly high (similar to 356 h(-1)). We establish that the low-energy/long-lived excitons preferencially transfer to Pd, paving a way for rational designing photocatalysts for various C-C coupling reactions.</p>
10a2D graphitic carbon nitride10aC-C cross-coupling10aexciton transfer10aheterogeneous photocatalyst10aPhotosensitization1 aMondal, Sanjit1 aSahoo, Lipipuspa1 aBanoo, Maqsuma1 aVaishnav, Yuvraj1 aVinod, Chathakudath, Prabhakara1 aGautam, Ujjal  uhttps://library.ncl.res.in/content/enhancing-catalytic-activity-pd-nanocrystals-towards-suzuki-cross-coupling-g-c3n4