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NiO nanoparticles were successfully prepared by decomposing the predecessor bis(glycinato)nickel(II)dihydrate in the presence of oleylamine and triphenylphosphine (TPP), and different approaches including Fourier transforms infrared spectrometry(FT-IR), X-ray diffraction(XRD) and transmission electron microscopy (TEM) were used to characterize the NiO nanoparticles. Meanwhile, the effects of TPP concentration and reaction time on the size and yield of NiO nanoparticles derived from precursors were thoroughly investigated in this paper. The analysis results indicated that the prepared NiO nanoparticles were found spherical in shape and demonstrated weak agglomeration. They had generally high purity and a fine crystal phase of cubic syngony. Furthermore, the effects of the TPP concentration and reaction time on the size and yield of NiO nanoparticles are very crucial, higher concentration of TPP would results in reduction of both the mean size and yield of NiO particles. However both yields and particles size of NiO nanoparticles continuously increased as increasing reaction time, after more than 60 minutes, the size and yield of NiO nanoparticles kept hardly change.

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BACKGROUND: Carbon materials have been regarded as valuable adsorbents for removal of volatile organic compounds (VOCs) owing to their high specific surface area and abundant pore structure. However, the complexity and high cost of the process used to treat the feedstock to produce commercial activated carbon has limited its application. In this reported study, a series of biochar materials was prepared using the KOH modification method employing corn cob as the raw material. The effects of different potassium hydroxide dosages, various activation temperatures and the activator addition method on the structure, physicochemical properties and VOC adsorption performance of the resulting biochars and their structure-activity relationship were systematically studied.RESULTS: Adsorption performance tests and a series of characterization results showed that the CC-3-700 (corn cob/KOH = 1:3, T = 700 °C, two-step dry mixing pyrolysis method) sample had highest toluene dynamic adsorption capacity (up to 573.5 mg g −1 ) compared to the other prepared samples. This result was attributed to the maximum specific surface area (2349 m 2 g −1 ) and pore volume (1.22 cm 3 g −1 ) of this sample. Moreover, the result suggested that the high specific surface area, abundant pore structure and highly disordered non-graphitizable carbon in sample CC-3-700 were the major reasons for its excellent adsorption performance. The results of a multi-component adsorption performance test showed that corn cob biochar had a strong adsorption capacity for toluene when simultaneously exposed to benzene and toluene. CONCLUSION:The results of this study revealed that the corn cob biochar prepared using a two-step roasting method offers good potential prospects for application in the field of VOC pollution control.

In this paper, a design of air pollutant monitoring system with six modules based on Semi-supervised learning (SSL) is designed. More specifically, the data acquisition module, data pre-processing module, data classifier module, comprehensive analysis module, auxiliary sorting module, computer terminal module respectively realize data collection, dimension reduction pre-processing, classification, comprehensive analysis, sorting, observation and monitoring. After system operation, it perfectly realized the real-time monitoring and timely warning of haze pollution, and provided data support for the precision of urban air pollution prevention. The application of modern science and technology in air pollution monitoring has been realized, and the ability and level of air pollution prevention and control supervision have been improved. The experimental results show that the proposed system has higher accuracy monitoring of classification．