以商品化Degussa P25为光催化剂,利用自制的旋转薄膜浆态光催化反应器(RFFS)光催化降解焦化废水,对影响COD去除率的各种因素进行了研究探讨。结果表明,COD的去除率随着焦化废水的初始COD值的降低显著上升,最佳的催化剂投加量为4.0 g/L...以商品化Degussa P25为光催化剂,利用自制的旋转薄膜浆态光催化反应器(RFFS)光催化降解焦化废水,对影响COD去除率的各种因素进行了研究探讨。结果表明,COD的去除率随着焦化废水的初始COD值的降低显著上升,最佳的催化剂投加量为4.0 g/L。对废水进行5倍稀释,调节pH值为3.2,加入3 mL H2O2,光照180 m in,在最佳TiO2投加量下的COD去除率可达97.3%。展开更多
A novel multi-tube photoreactor with 0.0188m3 valid reaction volume was constructed in pilot-scale. This rectangular reactor consisted of 13 regularly distributed silica glass tubes coating with TiO2 thin film photo-c...A novel multi-tube photoreactor with 0.0188m3 valid reaction volume was constructed in pilot-scale. This rectangular reactor consisted of 13 regularly distributed silica glass tubes coating with TiO2 thin film photo-catalyst. Total active area of TiO2 thin film is 0.3916m2. The ratio of surface area to volume achieves 20.8m-1. Photocatalytic experiment of phenol red demonstrates that the apparent reaction rate constant (k) is 0.074 65 h-1 and 0.16502h-1 for reaction system with and without micro-bubbles mixing. The corresponding apparent quantum efficiency (a) is 8.1771 X 10-7g.J-1 and 4.9036 x 10-7g-J-1, respectively. COD value of reactant could decrease to 17mg.L-1 and high performance liquid chromatography (HPLC) only shows two absorption peaks in 24 h pho-tocatalytic process time, so this photoreactor has good photomineralization effect. Experimental results reveal that photocatalytic destruction of organics is possible by using the multi-tube photoreactor.展开更多
The photocatalytic kinetics of BPA （4, 4＇-isopropylidenediphenol）, a representative endocrine disruptor, was explored using immobilized ZnO nanoparticles as a photocatalyst in a laboratory scale photocatalytic reac...The photocatalytic kinetics of BPA （4, 4＇-isopropylidenediphenol）, a representative endocrine disruptor, was explored using immobilized ZnO nanoparticles as a photocatalyst in a laboratory scale photocatalytic reactor. The conditions of photocatalytic degradation were optimized. Direct photocatalytic degradation of BPA was undertaken in an aqueous solution containing ZnO nanoparticles under the optimized experimental conditions. The effects of various factors, such as initial BPA concentrations, initial pH values and various anions （CI, NO3, COa2, SO42-, HCO3＂） were investigated. In the case of the nanoparticles derived films, the photocatalytic efficiency was found not to be remarkably related with the calcination temperature employed in the coating process. Screen-printed ZnO nanoparticles films obtained in the optimal processing conditions showed that the photocatalytic activity is comparable to ZnO nanoparticles in aqueous suspensions. Over 90% degradation efficiency of BPA was achieved under the optimum conditions. The degradation rates in all photocatalytic experiments were linear with the degradation efficiencies of BPA by regression analysis （r ≥ 0.99）. The results showed that the degradation kinetics of BPA in the reactor with immobilized nano-ZnO film as photocatalyst was in agreement with a pseudo-first order rate law.展开更多
We report fabrication and characterization of metal-semiconductor-metal photoconductive detectors based on Al-doped ZnO thin films fabricated by radio frequency magnetron sputtering.Optical and structural properties o...We report fabrication and characterization of metal-semiconductor-metal photoconductive detectors based on Al-doped ZnO thin films fabricated by radio frequency magnetron sputtering.Optical and structural properties of the thin films were characterized using various techniques.At 6 V bias,a responsivity higher than 4 A/W in the wavelength shorter than 350 nm was obtained,and this responsibility dropped quickly and reached the noise floor in the visible region.Transient response measurement revealed that the detector had a fast photoresponse with a rise time of 9 ns and a fall time of 1.2 μs.展开更多
文摘以商品化Degussa P25为光催化剂,利用自制的旋转薄膜浆态光催化反应器(RFFS)光催化降解焦化废水,对影响COD去除率的各种因素进行了研究探讨。结果表明,COD的去除率随着焦化废水的初始COD值的降低显著上升,最佳的催化剂投加量为4.0 g/L。对废水进行5倍稀释,调节pH值为3.2,加入3 mL H2O2,光照180 m in,在最佳TiO2投加量下的COD去除率可达97.3%。
基金supported by the National High Technology Research and Development Program of China(863Program,2009AA063003)the National Basic Research Program of China(973Program,2009CB220004)the Science and Technology Commission of Shanghai Municipality(0952nm01800))~~
基金Supported by the Natural Science Foundation of Jiangsu Province (JH01-010).
文摘A novel multi-tube photoreactor with 0.0188m3 valid reaction volume was constructed in pilot-scale. This rectangular reactor consisted of 13 regularly distributed silica glass tubes coating with TiO2 thin film photo-catalyst. Total active area of TiO2 thin film is 0.3916m2. The ratio of surface area to volume achieves 20.8m-1. Photocatalytic experiment of phenol red demonstrates that the apparent reaction rate constant (k) is 0.074 65 h-1 and 0.16502h-1 for reaction system with and without micro-bubbles mixing. The corresponding apparent quantum efficiency (a) is 8.1771 X 10-7g.J-1 and 4.9036 x 10-7g-J-1, respectively. COD value of reactant could decrease to 17mg.L-1 and high performance liquid chromatography (HPLC) only shows two absorption peaks in 24 h pho-tocatalytic process time, so this photoreactor has good photomineralization effect. Experimental results reveal that photocatalytic destruction of organics is possible by using the multi-tube photoreactor.
文摘The photocatalytic kinetics of BPA （4, 4＇-isopropylidenediphenol）, a representative endocrine disruptor, was explored using immobilized ZnO nanoparticles as a photocatalyst in a laboratory scale photocatalytic reactor. The conditions of photocatalytic degradation were optimized. Direct photocatalytic degradation of BPA was undertaken in an aqueous solution containing ZnO nanoparticles under the optimized experimental conditions. The effects of various factors, such as initial BPA concentrations, initial pH values and various anions （CI, NO3, COa2, SO42-, HCO3＂） were investigated. In the case of the nanoparticles derived films, the photocatalytic efficiency was found not to be remarkably related with the calcination temperature employed in the coating process. Screen-printed ZnO nanoparticles films obtained in the optimal processing conditions showed that the photocatalytic activity is comparable to ZnO nanoparticles in aqueous suspensions. Over 90% degradation efficiency of BPA was achieved under the optimum conditions. The degradation rates in all photocatalytic experiments were linear with the degradation efficiencies of BPA by regression analysis （r ≥ 0.99）. The results showed that the degradation kinetics of BPA in the reactor with immobilized nano-ZnO film as photocatalyst was in agreement with a pseudo-first order rate law.
基金supported by the National Natural Science Foundation of China (Grant No.50972007)the Beijing Municipal Natural Science Foundation (Grant No.4092035)+3 种基金the State Key Program for Basic Research of the Ministry of Science and Technology of China (Grant No.2011CB932703)the Special Items Fund of Beijing Municipal Commission of Educationthe Opened Fund of State Key Laboratory on Integrated Optoelectronicsthe National Science Fund for Distinguished Young Scholars (Grant No.60825407)
文摘We report fabrication and characterization of metal-semiconductor-metal photoconductive detectors based on Al-doped ZnO thin films fabricated by radio frequency magnetron sputtering.Optical and structural properties of the thin films were characterized using various techniques.At 6 V bias,a responsivity higher than 4 A/W in the wavelength shorter than 350 nm was obtained,and this responsibility dropped quickly and reached the noise floor in the visible region.Transient response measurement revealed that the detector had a fast photoresponse with a rise time of 9 ns and a fall time of 1.2 μs.
