The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons（Zr-AC, Ni-AC, Zn-AC） were successfully fabricated through microwave irradiation method. The synthesized nanoparticles ...The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons（Zr-AC, Ni-AC, Zn-AC） were successfully fabricated through microwave irradiation method. The synthesized nanoparticles were characterized using XRD, HR-SEM, XPS and BET. The optical properties of Zr-AC, Ni-AC and Zn-AC composites were investigated using UV–Vis diffuse reflectance spectroscopy. The photocatalytic efficiency was verified in the degradation of textile dyeing wastewater（TDW） in UV light irradiation. The chemical oxygen demand（COD） of TDW was observed at regular intervals to calculate the removal rate of COD. Zn-AC composites showed impressive photocatalytic enrichment, which can be ascribed to the enhanced absorbance in the UV light region, the effective adsorptive capacity to dye molecules, the assisted charge transfer and the inhibited recombination of electron-hole pairs. The maximum TDW degradation（82% COD removal） was achieved with Zn-AC. A possible synergy mechanism on the surface of Zn-AC was also designed. Zn-AC could be reused five times without exceptional loss of its activity.展开更多
Graphitic carbon nitride(g‐C3N4)nanosheet photocatalysts were synthesized via a facile impregnation‐thermal method.The as‐prepared materials were characterized and investigated as metal‐free photocatalysts for the...Graphitic carbon nitride(g‐C3N4)nanosheet photocatalysts were synthesized via a facile impregnation‐thermal method.The as‐prepared materials were characterized and investigated as metal‐free photocatalysts for the degradation of phenol in aqueous solution under visible light.Results revealed that the g‐C3N4nanosheets exhibited a78.9%degradation for phenol after30min,which was much faster than that of the pristine g‐C3N4.Using Brunauer‐Emmett‐Teller theory,the surface area of g‐C3N4nanosheets was103.24m2/g,which was much larger than that of g‐C3N4.The larger surface area increases the contact area of the material with phenol,enhancing the photocatalytic activity.These results highlight the potential application of sustainable metal‐free photocatalysts in water purification.展开更多
The authors study the asymptotic behavior of the smooth solutions to the Cauchy problems for two macroscopic models (hydrodynamic and drift-diffusion models) for semiconductors and the related relaxation limit problem...The authors study the asymptotic behavior of the smooth solutions to the Cauchy problems for two macroscopic models (hydrodynamic and drift-diffusion models) for semiconductors and the related relaxation limit problem. First, it is proved that the solutions to these two systems converge to the unique stationary solution time asymptotically without the smallness assump- tion on doping profile. Then, very sharp estimates on the smooth solutions, independent of the relaxation time, are obtained and used to establish the zero relaxation limit.展开更多
A three-layer structure of n-type organic semiconductors （PTCDA/PTCDA：PCBM/PCBM） is successfully identified as pho- toanode for photoelectrochemical water oxidation during the overall splitting of water into hydrog...A three-layer structure of n-type organic semiconductors （PTCDA/PTCDA：PCBM/PCBM） is successfully identified as pho- toanode for photoelectrochemical water oxidation during the overall splitting of water into hydrogen/oxygen in a nearly stoi- chiometric ratio （H2：O2 = 2：1） under visible irradiation （2 〉 420 nm）. A possible charge separation mechanism under visible light illumination was also proposed.展开更多
基金financial support rendered by the Salesians of Don BoscoDimapur Province+1 种基金NagalandNorth East India
文摘The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons（Zr-AC, Ni-AC, Zn-AC） were successfully fabricated through microwave irradiation method. The synthesized nanoparticles were characterized using XRD, HR-SEM, XPS and BET. The optical properties of Zr-AC, Ni-AC and Zn-AC composites were investigated using UV–Vis diffuse reflectance spectroscopy. The photocatalytic efficiency was verified in the degradation of textile dyeing wastewater（TDW） in UV light irradiation. The chemical oxygen demand（COD） of TDW was observed at regular intervals to calculate the removal rate of COD. Zn-AC composites showed impressive photocatalytic enrichment, which can be ascribed to the enhanced absorbance in the UV light region, the effective adsorptive capacity to dye molecules, the assisted charge transfer and the inhibited recombination of electron-hole pairs. The maximum TDW degradation（82% COD removal） was achieved with Zn-AC. A possible synergy mechanism on the surface of Zn-AC was also designed. Zn-AC could be reused five times without exceptional loss of its activity.
文摘Graphitic carbon nitride(g‐C3N4)nanosheet photocatalysts were synthesized via a facile impregnation‐thermal method.The as‐prepared materials were characterized and investigated as metal‐free photocatalysts for the degradation of phenol in aqueous solution under visible light.Results revealed that the g‐C3N4nanosheets exhibited a78.9%degradation for phenol after30min,which was much faster than that of the pristine g‐C3N4.Using Brunauer‐Emmett‐Teller theory,the surface area of g‐C3N4nanosheets was103.24m2/g,which was much larger than that of g‐C3N4.The larger surface area increases the contact area of the material with phenol,enhancing the photocatalytic activity.These results highlight the potential application of sustainable metal‐free photocatalysts in water purification.
基金Project supported by the National Natural Science Foundation of China, the Grant of MST of China,the National Natural Science
文摘The authors study the asymptotic behavior of the smooth solutions to the Cauchy problems for two macroscopic models (hydrodynamic and drift-diffusion models) for semiconductors and the related relaxation limit problem. First, it is proved that the solutions to these two systems converge to the unique stationary solution time asymptotically without the smallness assump- tion on doping profile. Then, very sharp estimates on the smooth solutions, independent of the relaxation time, are obtained and used to establish the zero relaxation limit.
基金supported by the National Natural Science Foundation of China (20920102034,20877076 & 20907056)the Major State Basic Research Development Program of China (2010CB933503 &2007CB613306)
文摘A three-layer structure of n-type organic semiconductors （PTCDA/PTCDA：PCBM/PCBM） is successfully identified as pho- toanode for photoelectrochemical water oxidation during the overall splitting of water into hydrogen/oxygen in a nearly stoi- chiometric ratio （H2：O2 = 2：1） under visible irradiation （2 〉 420 nm）. A possible charge separation mechanism under visible light illumination was also proposed.
