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We reported an electrochemical determination of caffeic acid (CA) based on the nitrogen doped carbon (NDC). The described sensor material was prepared by the flame synthesis method, which gave an excellent platform for the synthesis of carbon nanomaterials with the hetero atom dopant. The synthesized material was confirmed by various physical characterizations and it was further characterized by different electrochemical experiments. The NDC modified glassy carbon electrode (NDC/GCE) shows the superior electrocatalytic performance towards the determination of CA with the wide linear concentration range from 0.01 to 350 μM. It achieves the lowest detection limit of 0.0024 μM and the limit of quantification of 0.004 μM. The NDC/GCE-CA sensor reveals the good selectivity, stability, sensitivity and reproducibility which endorsed that the NDC is promising electrode for the determination of CA. In addition, NDC modified electrode is applied to the determination of CA in red wines and acquired good results.

The use of Ni loading can be significantly reduced in the application of CO2 hydrogenation, which can enhance catalytic activity and CH4 selectivity.

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Gold nanorods (AuNRs) have been widely used in photothermal conversion, and a coating of silica (SiO 2 ) provides higher thermal stability, better biocompatibility, and versatile chemical functionalization. In this work, two gold nanorods coated with surfactant-templated mesoporous silica layers of the same thickness but different porosities, and thus different specific surface areas, were prepared. Upon irradiation with 1064 nm nanosecond pulsed laser, the transient infrared emissions of AuNR@SiO 2 enveloped the stretching mode of the Si−O−Si bridge (1000− 1250 cm −1 ), the bending mode of adsorbed H 2 O (1600−1650 cm −1 ) within the mesoporous silica layer, and blackbody radiation, in terms of an underlying broad band (1000−2000 cm −1 ) probed with a step-scan Fourier transform spectrometer. The mesoporous silica shell and the adsorbed H 2 O gained populations of their vibrationally excited states, and the whole AuNR@SiO 2 was heated up via the photothermal energy of the core AuNRs. An average temperature after 5−10 μs within 80% of the emission intensity was ca. 200 °C. The decay of the emission at 1000−1250 and 1500− 1750 cm −1 was both accelerated, and the blackbody radiation components were negatively correlated with the porosity of the mesoporous silica layer. Higher porosity of the mesoporous silica layer was associated with more effective depopulation of the vibrationally excited states of the silica layers on the AuNRs via the nonradiative thermal conduction of the adsorbed H 2 O, since H 2 O has a larger thermal conduction coefficient than that of silica, in concomitance with the accelerated emission kinetics. This work unveils the roles of the porosity, capping materials, and entrapping molecules of a core−shell nanostructure during the thermalization after photoexcitation.

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We demonstrate highly efficient blue phosphorescence organic light-emitting diodes (PHOLED) with irregular stepwisedoping emitting layers (EMLs). High efficiency is realized by inserting a high-doping EML between two relatively lowdoping EMLs. Peak luminous efficiency and power efficiency of 19.2 cd A À1 and 18.0 lm W À1 are achieved, while those of a continuous stepwise-doping device are 9.8 cd A À1 and 8.6 lm W À1 . The dramatic efficiency enhancement is mainly attributed to the high hole-electron recombination probability and suppressed triplet excitons quenching by fine tuning the doping concentrations in the EMLs.