Ce-TiO_(2)-RGO composite photocatalyst was prepared by sol-gel method and ultrasonic treatment.The effect of Ce doping mass fraction on the degradation of textile printing and dyeing wastewater was studied.The catalys...Ce-TiO_(2)-RGO composite photocatalyst was prepared by sol-gel method and ultrasonic treatment.The effect of Ce doping mass fraction on the degradation of textile printing and dyeing wastewater was studied.The catalysts were characterized by XRD,SEM,TEM,UV-vis and PL.The results showed that,Ce-TiO_(2)particles uniformly adsorbed on the GO surface,and the particle diameter of Ce-TiO_(2)was approximately 25-110 nm.After Ce doping,the absorption band edge of TiO_(2)-RGO composite photocatalyst was redshifted and the band gap was reduced.With the increase of Ce doping mass fraction,the PL intensity of Ce-TiO_(2)-RGO composite photocatalyst first decreased and then slightly increased,and the emission peak intensity of 6%Ce-TiO_(2)-RGO composite photocatalyst was the lowest at 410 nm and 470 nm.Taking textile printing and dyeing wastewater as the research object of degradation,the COD removal rate of 6%Ce-TiO_(2)-RGO reached the maximum of 82.21%at 180 min,and the COD value after degradation was 88.95 mg/L which was in line with the wastewater discharge standard.On the other hand,at 180 min,the degradation rate for textile printing and dyeing wastewater by 6%Ce-TiO_(2)-RGO also reached the maximum(99.21%).Therefore,the Ce-TiO_(2)-RGO composite photocatalyst showed great application potential in the treatment of textile dyeing wastewater.展开更多
A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers...A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers into Cu matrix. The repeating Cu-SnO2-rGO structure was composed of inner dispersed reduced graphene oxide（r GO）, SnO2 as intermedia and outer Cu coating. SnO2 was introduced to the surface of rGO sheets in order to prevent the graphene aggregation with SnO2 serving as spacer and to provide enough active sites for subsequent Cu deposition. This process can guarantee rGO sheets to suffi ciently disperse and Cu nanoparticles to tightly and uniformly anchor on each layer of rGO by means of the SnO2 active sites as well as strictly control the reduction speed of Cu^2＋. The complete cover of Cu nanoparticles on rGO sheets thoroughly avoids direct contact among rGO layers. Hence, the repeating structure can simultaneously solve the wettability problem between rGO and Cu matrix as well as improve the bonding strength between rGO and Cu matrix at the well-bonded Cu-SnO2-rGO interface. The isolated rGO can effectively hinder the glide of dislocation at Cu-rGO interface and support the applied loads. Finally, the compressive strength of CMCs was enhanced when the strengthening effi ciency reached up to 41.展开更多
A facile synthesis of vanadium oxide with reduced graphene oxide（rGO） is developed and used as cathode material for lithium ion batteries. VO_2（B） nanorods and VO_2（B）-rGO composite were prepared by a hydrotherm...A facile synthesis of vanadium oxide with reduced graphene oxide（rGO） is developed and used as cathode material for lithium ion batteries. VO_2（B） nanorods and VO_2（B）-rGO composite were prepared by a hydrothermal method using NaVO_3 precursor and sodium oxalate as a reducing agent. The monoclinic phase and nanorod like morphology of synthesized materials were confirmed by XRD, SEM, and TEM respectively. The electrochemical properties of samples were investigated at 1.5–4.0 V, and 0.1 C rate,and the VO_2（B） nanorods exhibit reversible capacity of about 159 mAh g^（-1）, whereas VO_2（B）-rGO exhibits 274 mAh g^（-1）. The reasonable discharge capacities were obtained at high rates. The enhanced performance in electrical energy storage system reveals the effectiveness of rGO in the composite, as it enhances the conductive electron pathway to overcome the intrinsic limits of single phase VO_2（B）.展开更多
SnO2-reduced graphene oxide （SnO2-rGO） composites were prepared via a hydro-thermal reaction of graphene oxide （GO） and SnCI2·2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction,...SnO2-reduced graphene oxide （SnO2-rGO） composites were prepared via a hydro-thermal reaction of graphene oxide （GO） and SnCI2·2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction, GO was reduced to rGO while Sn2＋ was oxidized to Sn02, uniformly depositing on the surface of rGO sheets. The composites were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, thermogravimetric analysis （TGA）, infrared spectra analysis （IR） and transmission electron microscopy （TEM）, respectively, and their gas sensing properties were further investigated. Compared with pure SnO2 nanoparticles, the as-prepared SnO2-rGO gas sensor and response-recovery time to ethanol and H2S at responding and low cost SnO2-rGO gas sensor could showed much better gas sensing behavior in sensitivity ow concentrations. Overall, the highly sensitive, quick- be potentially applied in environmental monitoring area.展开更多
Enzymeless hydrogen peroxide （H2O2） detection with high sensitivity and excellent selectivity is desirable for clinical diagnosis. Herein, one-dimensional Co3O4 nanowires have been successfully constructed on reduce...Enzymeless hydrogen peroxide （H2O2） detection with high sensitivity and excellent selectivity is desirable for clinical diagnosis. Herein, one-dimensional Co3O4 nanowires have been successfully constructed on reduced graphene oxide （rGO） via a simple hydrothermal procedure and subsequent thermal treatment. These Co3O4 nanowires, assembled by small nanoparticles, are interlaced with one another and make a spider web-like structure on rGO. The formation of Co3O4-rGO hybrids is attributed to the structure-directing and anchoring roles of DDA and GO, respectively. The resulting structure possesses abundant active sites, the oriented transmission of electrons, and unimpeded pathways for matter diffusion, which endows the Co3O4-rGO hybrids with excellent electrocatalytic performance. As a result, the obtained Co3O4-rGO hybrids can serve as an efficient electrochemical catalyst for H2O2 oxidation and high sensitivity detection. Under physiological conditions, the oxidation current of H2O2 varies linearly with respect to its concentration from 0.015 to 0.675 mM with a sensitivity of 1.14 mA.mM^-1.cm^-2 and a low detection limit of 2.4 μM. Furthermore, the low potential （-0.19 V） and the good selectivity make Co3O4-rGO hybrids suitable for monitoring H2O2 generated by liver cancer HepG2 cells. Therefore, it is promising as a non-enzymatic sensor to achieve real-time quantitative detection of H2O2 in biological applications.展开更多
文摘Ce-TiO_(2)-RGO composite photocatalyst was prepared by sol-gel method and ultrasonic treatment.The effect of Ce doping mass fraction on the degradation of textile printing and dyeing wastewater was studied.The catalysts were characterized by XRD,SEM,TEM,UV-vis and PL.The results showed that,Ce-TiO_(2)particles uniformly adsorbed on the GO surface,and the particle diameter of Ce-TiO_(2)was approximately 25-110 nm.After Ce doping,the absorption band edge of TiO_(2)-RGO composite photocatalyst was redshifted and the band gap was reduced.With the increase of Ce doping mass fraction,the PL intensity of Ce-TiO_(2)-RGO composite photocatalyst first decreased and then slightly increased,and the emission peak intensity of 6%Ce-TiO_(2)-RGO composite photocatalyst was the lowest at 410 nm and 470 nm.Taking textile printing and dyeing wastewater as the research object of degradation,the COD removal rate of 6%Ce-TiO_(2)-RGO reached the maximum of 82.21%at 180 min,and the COD value after degradation was 88.95 mg/L which was in line with the wastewater discharge standard.On the other hand,at 180 min,the degradation rate for textile printing and dyeing wastewater by 6%Ce-TiO_(2)-RGO also reached the maximum(99.21%).Therefore,the Ce-TiO_(2)-RGO composite photocatalyst showed great application potential in the treatment of textile dyeing wastewater.
基金Funded by the National Natural Science Foundation of China(51572208)the 111 Project(B13035)+1 种基金the National Natural Science Foundation of Hubei Province(2014CFB257 and 2014CFB258)the Fundamental Research Funds for the Central Universities(WUT:2015-III-059)
文摘A novel chemical technique combined with unique plasma activated sintering（PAS） was utilized to prepare consolidated copper matrix composites（CMCs） by adding Cu-SnO2-rGO layered micro powders as reinforced fillers into Cu matrix. The repeating Cu-SnO2-rGO structure was composed of inner dispersed reduced graphene oxide（r GO）, SnO2 as intermedia and outer Cu coating. SnO2 was introduced to the surface of rGO sheets in order to prevent the graphene aggregation with SnO2 serving as spacer and to provide enough active sites for subsequent Cu deposition. This process can guarantee rGO sheets to suffi ciently disperse and Cu nanoparticles to tightly and uniformly anchor on each layer of rGO by means of the SnO2 active sites as well as strictly control the reduction speed of Cu^2＋. The complete cover of Cu nanoparticles on rGO sheets thoroughly avoids direct contact among rGO layers. Hence, the repeating structure can simultaneously solve the wettability problem between rGO and Cu matrix as well as improve the bonding strength between rGO and Cu matrix at the well-bonded Cu-SnO2-rGO interface. The isolated rGO can effectively hinder the glide of dislocation at Cu-rGO interface and support the applied loads. Finally, the compressive strength of CMCs was enhanced when the strengthening effi ciency reached up to 41.
基金supported financially by DST-SERB Govt of India, New Delhi (SB/FT/CS-083/2012)DST Nanomission Govt.of India, New Delhi (Project No.SR/NM/NS-1262/2013 (G) dated 18-03-2015) for financial support
文摘A facile synthesis of vanadium oxide with reduced graphene oxide（rGO） is developed and used as cathode material for lithium ion batteries. VO_2（B） nanorods and VO_2（B）-rGO composite were prepared by a hydrothermal method using NaVO_3 precursor and sodium oxalate as a reducing agent. The monoclinic phase and nanorod like morphology of synthesized materials were confirmed by XRD, SEM, and TEM respectively. The electrochemical properties of samples were investigated at 1.5–4.0 V, and 0.1 C rate,and the VO_2（B） nanorods exhibit reversible capacity of about 159 mAh g^（-1）, whereas VO_2（B）-rGO exhibits 274 mAh g^（-1）. The reasonable discharge capacities were obtained at high rates. The enhanced performance in electrical energy storage system reveals the effectiveness of rGO in the composite, as it enhances the conductive electron pathway to overcome the intrinsic limits of single phase VO_2（B）.
基金supported by the University of Science and Technology BeijingNational Center for Nanoscience and Technology Beijingthe National Basic Research Program of China (No.2007CB714304)
文摘SnO2-reduced graphene oxide （SnO2-rGO） composites were prepared via a hydro-thermal reaction of graphene oxide （GO） and SnCI2·2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction, GO was reduced to rGO while Sn2＋ was oxidized to Sn02, uniformly depositing on the surface of rGO sheets. The composites were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, thermogravimetric analysis （TGA）, infrared spectra analysis （IR） and transmission electron microscopy （TEM）, respectively, and their gas sensing properties were further investigated. Compared with pure SnO2 nanoparticles, the as-prepared SnO2-rGO gas sensor and response-recovery time to ethanol and H2S at responding and low cost SnO2-rGO gas sensor could showed much better gas sensing behavior in sensitivity ow concentrations. Overall, the highly sensitive, quick- be potentially applied in environmental monitoring area.
文摘Enzymeless hydrogen peroxide （H2O2） detection with high sensitivity and excellent selectivity is desirable for clinical diagnosis. Herein, one-dimensional Co3O4 nanowires have been successfully constructed on reduced graphene oxide （rGO） via a simple hydrothermal procedure and subsequent thermal treatment. These Co3O4 nanowires, assembled by small nanoparticles, are interlaced with one another and make a spider web-like structure on rGO. The formation of Co3O4-rGO hybrids is attributed to the structure-directing and anchoring roles of DDA and GO, respectively. The resulting structure possesses abundant active sites, the oriented transmission of electrons, and unimpeded pathways for matter diffusion, which endows the Co3O4-rGO hybrids with excellent electrocatalytic performance. As a result, the obtained Co3O4-rGO hybrids can serve as an efficient electrochemical catalyst for H2O2 oxidation and high sensitivity detection. Under physiological conditions, the oxidation current of H2O2 varies linearly with respect to its concentration from 0.015 to 0.675 mM with a sensitivity of 1.14 mA.mM^-1.cm^-2 and a low detection limit of 2.4 μM. Furthermore, the low potential （-0.19 V） and the good selectivity make Co3O4-rGO hybrids suitable for monitoring H2O2 generated by liver cancer HepG2 cells. Therefore, it is promising as a non-enzymatic sensor to achieve real-time quantitative detection of H2O2 in biological applications.
