Suxiang Ge

Preparation and Optical Properties of Spherical Bi2S3 Nanoparticles by In Situ Thermal Sulfuration Method

Spherical Bi2S3 nanoparticles (NPs) were prepared by a facile in situ thermal sulfuration method. Different Bi2S3 samples were obtained by controlling the sulfuration time. The products were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), Raman and Fourier-transform infrared (FT-IR) methods. The optical properties were examined by UV-visible-near-infrared (UV-Vis–NIR) and photoluminescence (PL) techniques. The results show that the phase of the products after sulfuration is pure and the spherical shape of Bi NPs has been successfully transmitted to Bi2S3 samples. The light absorption edges exhibit red shift to 1060 nm while the light emission displays blue shift to 868 nm, compared with the energy bandgap of bulk Bi2S3. The reason for the special optical properties of Bi2S3 NPs by this in situ sulfuration route is considered to associate with the defects and quantum size effect of NPs.

Development of 2-Chlorophenol Sensor Based on a Fiber Optic Oxygen Transducer via Oxidation Reaction Catalyzed by Tetranitro Iron (II) Phthalocyanine

This paper develops a 2-chlorophenol sensor based on the improvement of a fiber optic oxygen transducer. The measurement of a sensor depends on the principle of stoichiometric relationship between dissolved oxygen and 2-chlorophenol in catalytic oxidation reaction. Specifically, oxygen was consumed fast in oxidation of 2-chlorophenol catalyzed by tetranitro iron (II) phthalocyanine (TNFe(II)Pc), and the concentration changes of dissolved oxygen could be measured by a fiber optic oxygen transducer. The phase-modulation technology was employed to record the signals of phase delay responding to the aerobic oxidation process catalyzed by TNFe(II)Pc. In addition, the sensing performance of this sensor could be demonstrated by a modified Stern-Volmer equation, φ = 0.12 + 3710[2 - CP] (R2 = 0.9949), where φ and [2-CP] represent the phase delay and concentration of 2-chlorophenol, respectively. The detection limit of this sensor is 8.0 × 10-7 M. In addition, this sensor shows the satisfactory results compared with that of HPLC method for detection of the samples from Changjiang river.

Preparation and Optical Properties of CuS Nanofilms by a Facile Two-Step Process

CuS nanofilms were prepared by a facile two-step process including chemical bath deposition of Cu nanofilms first and the subsequent thermal sulfuration step. The composition and structure of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Raman spectroscopy. The optical properties of CuS nanofilms were determined by Ultraviolet-visible (UV-Vis) technique. The results show that the nanofilms composed by Cu spherical nanoparticles were completely transformed to the nanofilms composed by CuS nanosheets when the sulfuration temperature was 350∘C. The light absorption edges of CuS nanofilms exhibit red shift when sulfuration occurred at lower temperature. A plausible growth mechanism related with gas phase reaction for formation of CuS nanofilms was also proposed.

Insight into the reactivity difference of two iron phthalocyanine catalysts in chromogenic reaction: DFT theoretical study

ABSTRACT Chromogenic reaction catalyzed by metal phthalocyanine (MPc) complexes is a novel and practical method for the facile identification of phenolic pollutants. Exploring the catalytic reaction mechanism is the current concern in the investigation. In this work, tetranitro iron (II) phthalocyanine (TNFe(II)Pc) and iron (II) phthalocyanine (Fe(II)Pc) catalyzed chromogenic reactions were studied at the B3LYP level on the basis of the density functional theory (DFT) calculation. The molecular structure, atomic charge, and frontier molecular orbital of these two kinds of iron phthalocyanine complex were investigated. The calculation results demonstrate that no obvious difference for geometry structures of Fe(II)Pc and TNFe(II)Pc macrocycle can be found, while the atomic charge of Fe atom increases obviously with the four nitro groups substituted on the peripheral of macrocycle. By applying the descriptor of donor–acceptor molecular hardness, the difference of electron transfer from chlorophenol substrates to TNFe(II)Pc/Fe(II)Pc was well explained. Our investigations could provide a new strategy in designing various MPc catalysts for chromogenic identification of chlorophenol pollutants.

Daylight-driven photocatalytic degradation of ionic dyes with negatively surface-charged In2S3 nanoflowers: dye charge-dependent roles of reactive species

Even though dye degradation is a successful application of semiconductor photocatalysis, the roles of reactivexa0species inxa0dye degradation have not received adequate attention. In this study, we systematically investigated the degradation of two cationic dyes (rhodamine B and methylene blue) and two anionic dyes (methyl orange and orange G) over negatively surface-charged In2S3 nanoflowers synthesized at 80xa0°C under indoor daylight lamp irradiation. It is notable to find In2S3 nanoflowers were more stable in anionic dyes degradation compared to that in cationic dyes removal. The active species trapping experiments indicated photogenerated electrons were mainly responsible for cationic dyes degradation, but holes were more important in anionic dyes degradation. A surface-charge-dependent role of reactive species in ionic dye degradation was proposed for revealing such interesting phenomenon. This study would provide a new insight for preparing highly efficient daylight-driven photocatalyst for ionic dyes degradation.