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Utilizing halide perovskites for photocatalytic aromatic C(sp3)H bond activation remains a great challenge due to the serious recombination of photogenerated charge carriers and slow reaction dynamics of the materials themselves. Herein, a lead‐free perovskite‐based hybrid of Cs3Sb2Br9/g‐C3N4 nanosheet is constructed and applied for photocatalytic aromatic C(sp3)H bond activation, which shows enhanced photocatalytic performance. By introducing ultrathin g‐C3N4 nanosheets as the heterogeneous nucleation sites, size‐reduced and well‐dispersed Cs3Sb2Br9 nanocrystals can be obtained. The as‐formed close contact and high‐quality heterointerface between Cs3Sb2Br9 and g‐C3N4 provides pathways for fast charge transfer which is beneficial to improve the separation efficiency of photogenerated electron−hole pairs. Under visible light irradiation, the Cs3Sb2Br9/g‐C3N4 hybrid photocatalyst can effectively oxidize toluene toward benzaldehyde and benzyl alcohol with a total conversion rate of 8346.8 μmol g−1 h−1, which is 26.6‐ and 6.0‐fold that of pure g‐C3N4 and Cs3Sb2Br9, respectively. This work demonstrates the potential of all‐inorganic lead‐free halide perovskite‐based heterostructures for photocatalytic organic reactions. [ABSTRACT FROM AUTHOR]

A novel one-pot 1,3-dipolar cycloaddition/oxidation reaction of 1,4-quinones, aromatic aldehydes, and N -substituted amino esters to construct polysubstituted benzo[ f ]isoindole-4,9-diones induced by benzoic acid is reported. Based on optimized reaction conditions, various polysubstituted benzo[ f ]isoindole-4,9-diones derivatives are obtained in moderate yields. This straightforward methodology employs mild reaction conditions, a green oxidant, and readily available starting materials. Notably, a wide range of substrates is tolerated. [ABSTRACT FROM AUTHOR]

Silicon nanowires with high density, uniform distribution and large area were produced directly from Si(100) based on solid-liquid-solid mechanism under the growth temperature of 1 100 ℃ with 30 min. The flow of N2 is 1 500 sccm and Au-Al films is used as metallic catalyst. The diameters of Si nanowires is 50~120 nm and the lengths of the formed Si nanowires is hundreds of nanometers. After that Tb-doped Si nanowires were reserched. We experimentally investigated the influences of the different process parameters on the luminescence of Tb-doped Si nanowires.The main process parameters includ doping temperature(1 000~1 200 ℃), doping time (30~90 min) and gas flow rate of N2 (0~1 000 sccm). Finally, Tb-doped bulk silicon substrates have been studied experimentally. We characterized and analyzed the photoluminescence properties of Tb-doped Si nanowires with the Hitachi F-4600 fluorescence spectrophotometer. The corresponding relation of energy level structure and transition properties of Tb ion with the experimental spectrum is analyzed in detail. The experiment result indicates that the Tb-doped Si nanowires have a stronly green luminescencent. The emission peak position of the largest intensity at 554 nm (5D4→7F5) with the doping temperature 1 100 ℃, the flow of N2 1 000 sccm and the excitation wavelength 243 nm. At the same time,three emission bands of 494 nm (5D4→7F6), 593 nm (5D4→7F4) and 628 nm (5D4→7F3) were observed under room temperature. The Tb-doped Si nanowires appeared strong green light emission compared with the bulk silicon substrate. Its application has a certain reference value for studying the characteristics of luminescence of rare earth element doped Si based material. Meanwhile,the photoluminescence properties of Tb-doped Si nanowires affected by the diameter, length, distribution and density of Si nanowires. That is necessary forour further research.