RESUMO
Bi2O2CO3 modified graphitic carbon nitride (g-C3N4) nanosheets were prepared by a simple one-pot synthetic strategy. In the presence of ammonium nitrate, different mass ratios of bismuth nitrate/melamine were used to fabricate these catalysts, which were characterized by X-ray diffraction (XRD), N2-physisorption, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis analysis, and photoluminescence (PL). The catalytic properties of composites were evaluated by photodegrading tetracycline hydrochloride (TC) under visible light irradiation. Among these catalysts, Bi2O2CO3(1.5)/g-C3N4 showed the highest catalytic activity, which was more than 16 times greater than the pristine g-C3N4 material. The improved photocatalytic properties of Bi2O2CO3/g-C3N4 may be due to the formation of a heterojunction between Bi2O2CO3 and g-C3N4, leading to the effective separation of photo-induced carriers and the enhanced absorption of visible light. Furthermore, the Bi2O2CO3/g-C3N4 composites had considerable catalytic stability, which was a key element for their potential applications.
Assuntos
Catálise , Grafite , Modelos Químicos , Luz , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
The photocatalytic properties of ZnO-CuO catalysts supported on siliceous MCM-48 (Mobil Composition of Matter No. 48) for the degradation of organic pollutions such as methylene blue and salicylic acid under UV light irradiation were investigated. These catalysts were prepared by impregnation of MCM-48 with a mixed aqueous solution of copper acetate and zinc acetate. X-ray diffraction, N2-physisorption, high resolution transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and photoluminescence were used to characterize these samples. Results from characterizations showed that the addition of ZnO to CuO/MCM-48 could markedly improve the photocatalytic degradation properties. The enhanced photocatalytic behaviors of ZnO-CuO/MCM-48 may be due to the formation of p-n heterojunctions between ZnO and CuO, resulting in the effective separation of photogenerated electron-hole pairs. Moreover, the photocatalysts were easily recovered and reused for five cycles without considerable loss of activity.
Assuntos
Cobre/química , Azul de Metileno/química , Ácido Salicílico/química , Óxido de Zinco/química , Catálise/efeitos da radiação , Espectroscopia Fotoeletrônica , Fotólise/efeitos da radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Raios Ultravioleta , Difração de Raios X , Óxido de Zinco/síntese químicaAssuntos
Aminas/química , Compostos Heterocíclicos/síntese química , Compostos Azo/química , Catálise , Cristalografia por Raios X , Ciclização , Compostos Heterocíclicos/química , Ligação de Hidrogênio , Iminas/química , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo , Tiossemicarbazonas/químicaRESUMO
Single crystalline Li4Mn5O12 nanowires with cubic phase were prepared in a large scale by a simple molten salt route without using any surfactant as template; the nanowires exhibited high storage capacity and coulombic efficiency as cathode materials for lithium-ion batteries.
