Understanding the relationship between structure and properties is critical to the development of solidstate luminescence materials with desired characteristics and performance optimization. In this work, we elaborate...Understanding the relationship between structure and properties is critical to the development of solidstate luminescence materials with desired characteristics and performance optimization. In this work, we elaborately designed and synthesized a pair of mononuclear iridium(Ⅲ) complexes with similar structures but different degrees of cationization. [Ir2-f][2PF_(6)] with two counterions is obtained by simple Nmethylation of the ancillary ligand of [Ir1-f][PF_(6)] which is a classic cationic iridium(Ⅲ) complex. Such a tiny modification results in tremendously different optical properties in dilute solutions and powders.[Ir1-f][PF_(6)] exhibits weak light in solution but enhanced emission in solid-state as well as poly(methyl methacrylate) matrix, indicative of its aggregation-induced emission(AIE) activity. On the sharp contrary, [Ir2-f][2PF_(6)] is an aggregation-caused quenching(ACQ) emitter showing strong emission in the isolated state but nearly nonemissive in aggregation states. Benefiting from the appealing characteristics of mechanochromic luminescence and AIE behavior, [Ir1-f][PF_(6)] has been successfully applied in reversible re-writable data recording and cell imaging. These results might provide deep insights into AIE and ACQ phenomenon of iridium(Ⅲ) complexes and facilitate the development of phosphorescent materials with promising properties.展开更多
Atomic force microscopy（AFM） is a commonly used technique for graphene thickness measurement.However, due to surface roughness caused by graphene itself and variation introduced in AFM measurement, graphene thicknes...Atomic force microscopy（AFM） is a commonly used technique for graphene thickness measurement.However, due to surface roughness caused by graphene itself and variation introduced in AFM measurement, graphene thickness is difficult to be accurately determined by AFM. In this paper, a histogram method was used for reliable measurements of graphene thickness using AFM. The influences of various measurement parameters in AFM analysis were investigated. The experimental results indicate that significant deviation can be introduced using various order of flatten and improperly selected measurement parameters including amplitude setpoint and drive amplitude. At amplitude setpoint of 100 mV and drive amplitude of 100 m V, thickness of 1 layer（1L）, 2 layers（2L） and 4 layers（4L） graphene were measured.The height differences for 1L, 2L and 4L were 1.51 ± 0.16 nm, 1.92 ± 0.13 nm and 2.73 ± 0.10 nm, respectively. By comparing these values, thickness of single layer graphene can be accurately determined to be0.41 ± 0.09 nm.展开更多
Surface functionalization of piezoelectric greatly determines its piezo-catalytic activity and selectivity in that functional group affect specific reactants’surface adsorption and activation abilities.Herein,we prop...Surface functionalization of piezoelectric greatly determines its piezo-catalytic activity and selectivity in that functional group affect specific reactants’surface adsorption and activation abilities.Herein,we propose chemical functionalization on the surface of nano-scaled BaTiO_(3) piezoelectric via a one-pot hydrothermal process using polyethylene glycol as surfactant,and evaluate its piezo-catalytic activity and selectivity by degrading model antibiotic and dye reactants under ultrasonic vibrations.Acetate or/and oxalic unidentate ligands on the surface of BaTiO_(3) nanobelts can be formed by controlling precursor and hydrothermal parameters.Particularly,oxalic acid functionalized BaTiO_(3) nanobelts presented a high piezo-catalytic rate constant of 0.068 min^(-1) for Rhodamine B solution and maintained>87%degradation efficiency within 30 min under the condition of ultrasonic bath with 40 kHz and 100 W,which was mainly ascribed to piezo-sensitization effect.This work provides references for the preparation of chemical functionalized catalysts and also contributes to the development of novel catalysts for special applications.展开更多
基金financial support from the National Natural Science Foundation of China(Nos.22175033 and 51902124).
文摘Understanding the relationship between structure and properties is critical to the development of solidstate luminescence materials with desired characteristics and performance optimization. In this work, we elaborately designed and synthesized a pair of mononuclear iridium(Ⅲ) complexes with similar structures but different degrees of cationization. [Ir2-f][2PF_(6)] with two counterions is obtained by simple Nmethylation of the ancillary ligand of [Ir1-f][PF_(6)] which is a classic cationic iridium(Ⅲ) complex. Such a tiny modification results in tremendously different optical properties in dilute solutions and powders.[Ir1-f][PF_(6)] exhibits weak light in solution but enhanced emission in solid-state as well as poly(methyl methacrylate) matrix, indicative of its aggregation-induced emission(AIE) activity. On the sharp contrary, [Ir2-f][2PF_(6)] is an aggregation-caused quenching(ACQ) emitter showing strong emission in the isolated state but nearly nonemissive in aggregation states. Benefiting from the appealing characteristics of mechanochromic luminescence and AIE behavior, [Ir1-f][PF_(6)] has been successfully applied in reversible re-writable data recording and cell imaging. These results might provide deep insights into AIE and ACQ phenomenon of iridium(Ⅲ) complexes and facilitate the development of phosphorescent materials with promising properties.
基金supported by the Program of National Key Technology R&D Program of the Ministry of Science and Technology of China(2011BAK15B04)
文摘Atomic force microscopy（AFM） is a commonly used technique for graphene thickness measurement.However, due to surface roughness caused by graphene itself and variation introduced in AFM measurement, graphene thickness is difficult to be accurately determined by AFM. In this paper, a histogram method was used for reliable measurements of graphene thickness using AFM. The influences of various measurement parameters in AFM analysis were investigated. The experimental results indicate that significant deviation can be introduced using various order of flatten and improperly selected measurement parameters including amplitude setpoint and drive amplitude. At amplitude setpoint of 100 mV and drive amplitude of 100 m V, thickness of 1 layer（1L）, 2 layers（2L） and 4 layers（4L） graphene were measured.The height differences for 1L, 2L and 4L were 1.51 ± 0.16 nm, 1.92 ± 0.13 nm and 2.73 ± 0.10 nm, respectively. By comparing these values, thickness of single layer graphene can be accurately determined to be0.41 ± 0.09 nm.
基金The authors appreciate funding from National College Students Innovation and Entrepreneurship Training Program of China(No.201910356015).
文摘Surface functionalization of piezoelectric greatly determines its piezo-catalytic activity and selectivity in that functional group affect specific reactants’surface adsorption and activation abilities.Herein,we propose chemical functionalization on the surface of nano-scaled BaTiO_(3) piezoelectric via a one-pot hydrothermal process using polyethylene glycol as surfactant,and evaluate its piezo-catalytic activity and selectivity by degrading model antibiotic and dye reactants under ultrasonic vibrations.Acetate or/and oxalic unidentate ligands on the surface of BaTiO_(3) nanobelts can be formed by controlling precursor and hydrothermal parameters.Particularly,oxalic acid functionalized BaTiO_(3) nanobelts presented a high piezo-catalytic rate constant of 0.068 min^(-1) for Rhodamine B solution and maintained>87%degradation efficiency within 30 min under the condition of ultrasonic bath with 40 kHz and 100 W,which was mainly ascribed to piezo-sensitization effect.This work provides references for the preparation of chemical functionalized catalysts and also contributes to the development of novel catalysts for special applications.
