“直面环境”:印刷企业的变革系列二 从“能见化”到“减排”

全球化时代,因发展需要,由此带来的利益追逐,极大地刺激了人类的消费欲望与功利心态,导致地球临近"成长的界限",造成严重的生态失衡和气候变暖。我们正在不断努力不让环境继续恶化,针对气候变暖问题积极探索新的应对措施。为此,本刊将陆续刊登日本印刷企业在"直面环境"中的新措施,并加以探讨。

Solvent-assisted synthesis of porous g-C_3N_4 with efficient visible-light photocatalvtic performance for NO removal

Graphitic carbon nitride（g-C3N4） with efficient photocatalytic activity was synthesized through thermal polymerization of thiourea with the addition of water（CN-W） or ethanol（CN-E） at 550 ℃for 2 h.The physicochemical properties of the g-C3N4 were investigated by X-ray diffraction,transmission electron microscopy,ultraviolet-visible spectroscopy,photoluminescence spectroscopy,diffuse-reflection spectroscopy,BET and BJH surface area characterization,and elemental analysis.The carbon content was found to have self-doped into the g-C3N4 matrix during the thermal polymerization of thiourea and ethanol.CN-W and CN-E showed considerably enhanced visible-light photocatalytic activity,with NO removal percentages of 37.2%and 48.3%,respectively.Compared with pure g-C3N4,both the short and long lifetimes of the charge carriers in CN-W and CN-E were found to be prolonged.The mechanism of improved visible-light photocatalytic activity was deduced.The present work may provide a facile route to optimize the microstructure of g-C3N4photocatalysts for high-performance environmental and energy applications.

“直面环境”:印刷企业的变革系列三 通向“绿色就是黑色”的路程

全球化时代,因发展需要,由此带来的利益追逐,极大地刺激了人类的消费欲望与功利心态,导致地球临近"成长的界限",造成严重的生态失衡和气候变暖。我们正在不断努力不让环境继续恶化,针对气候变暖问题积极探索新的应对措施。为此,本刊将陆续刊登日本印刷企业在"直面环境"问题中的新措施,并加以探讨。

“直面环境”:印刷企业的变革系列一 印刷企业的环境应对

全球化时代,因发展需要,由此带来的利益追逐,极大地刺激了人类的消费欲望与功利心态,导致地球临近"成长的界限",造成严重的生态失衡和气候变暖。我们正在不断努力不让环境继续恶化,针对气候变暖问题积极探索新的应对措施。为此,本刊将陆续刊登日本印刷企业在"直面环境"问题中的新措施,并加以探讨。

Visible light promoted difunctionalization reactions of alkynes

Visible light promoted difunctionalization of alkynes is reviewed. The difunctionalization reaction is achieved by different reagents. Radicals such as carbon(sp3), carbon(sp2), and other heteroatom(P, S, N, Se, O, and halide) radicals initiated by visible light can undergo radical addition to a carbon-carbon triple bond. Upon further transformation, the desired difunctionalized products are obtained. Some organometallic complexes can be activated by visible light;the difunctionalization of alkynes is catalyzed by these species. Other reagents like 1,3-dipole precursors could also react with alkynes to give difunctionalization products;here, the 1,3-dipole derivatives are obtained by visible light photocatalysis. So far, the strategy has been succeeded in the formation of C–C bonds and C–X bonds. Several valuable chemical skeletons have been constructed under mild conditions. However, high regio-and stereoselectivities in some direct difunctionalization methodologies are yet to be achieved.

Comparative research on visibility and light extinction of PM_(2.5)components during 2014–17 in the North China plain

Severe air pollution with visibility deterioration has long been a focus in the North China Plain(NCP).In this study,concentration and light extinction analysis of PM_(2.5)chemical components were carried out from 2014 to 2017 to study the pollution characteristics in Baoding,a case city of the NCP.The annual average concentration of total PM_(2.5)components showed a declining trend,decreasing by 11μg m^(−3)(water-soluble inorganic ions),23μg m^(−3)(carbonaceous aerosols),and 1796 ng m^(−3)(inorganic elements).Contributing 82.9%to the concentration of total ions,the dominant components,NH 4+,NO 3−,and SO_(4)^(2−)became the main pollutants in PM_(2.5)pollution.Based on the IMPROVE algorithm,the average reconstructed PM_(2.5)mass concentration was 93±69μg m^(−3)during the observation period.Meanwhile,the light extinction coefficients were 373.8±233.6 M^(m−1),405.3±300.1M^(m−1),554.3±378.2M^(m−1)and 1005.2±750.3M^(m−1),in spring,summer,autumn,and winter,respectively.Ammonium sulfate,ammonium nitrate,and organic matter were the largest contributors to light extinction,accounting for a total of 55%–77%in the four seasons.The b sca(light scattering by particles and gases)reconstructed from PM_(2.5)components(Rb_(sca))and the b sca converted from visibility(Vb_(sca))were compared to evaluate the performance of the IMPROVE algorithm,revealing a high correlation coefficient of 0.84.The high values of Vb_(sca)were underestimated while the low values were overestimated,as determined through comparison with the one-to-ne line.Especially,when Rb_(sca)>1123M^(m−1)(corresponding to<2.0 km,approximately),Vb_(sca)was underestimated by 17.6%.PM_(2.5)mass concentration and relative humidity also had an impact on the estimation.

Preparation and photocatalysis properties of composite photocatalyst CoPcS/TiO2/K2Ti4O9

Photocatalyst CoPcS/TiO2 was prepared by sol-gel method. Composite CoPcS/TiO2/K2Ti4O9 was prepared by dipping. It was incandesced at various temperatures and modification effect was compared. The results showed that optical absorption of sample incandesce at 423K occurred significant red-shift. Light absorption width extended from ultraviolet region to visible region, especially there was an intensive absorption between 600 nm and 680 nm. X-ray diffraction spectrogram showed that TiO2 in sample still maintained anatase crystal form. Under the illumination of visible light, photocatalysis degradation experiment was taken with Eosin B as simulated pollutants. Decoloration rate of Eosin B was much improved. The rate can reach 80% in 300 minutes.

Mg and Ni Incorporated ZnO Diluted Magnetic Semiconductor for Magnetic and Photo-Catalytic Applications

Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.

Visible-Light Photoredox-Catalyzed Carbon/Carboxylation of Alkenes with Malonates and CO_(2)

A photoredox-catalyzed cascade carbon/carboxylation of activated alkenes with malonates acetals and CO_(2) has been achieved,leading to a range of functionalized 1,1,3-tricarboxylates in good efficiency under mild reaction conditions.This reaction provides a facile and sustainable method for the synthesis of tricarboxylates by using CO_(2) as the carboxylic source.

Novel multi-heterostructured Pt-BiOBr/TiO2 nanotube arrays with remarkable visible-light photocatalytic performance and stability

Unique multiple heterojunction of Pt-BiOBr/TiO2 nanotube arrays（Pt-BiOBr/TNTAs） was achived by successively loading both Pt nanoparticles（NPs） and BiOBr nanoflkes（NFs） on surface of ordered and spaced TiO2 nanotubes（NTs） using anodization followed by solvothermal and sequential chemical bath deposition（S-CBD） method. The fabricated Pt-Bi OBr/TNTAs were fully characterized, and the photocatalytic（PC） activity and stability of PtBiOBr/TNTAs toward degradation of methyl orange（MO） under visible-light irradiation（λ＆gt;400 nm） were evaluated. The results reveal that multiple heterostructures of Pt/TiO2, Pt/BiOBr and BiOBr/TiO2 are constructed among TNTAs substrate, Pt NPs and BiOBr NFs, and the hybrid Pt-BiOBr/TNTAs catalyst exhibits remarkable visible-light PC activity, favourable reusability and long-term stability. The combined effect of several factors may contribute to the remarkable PC performance, including strong visible-light absorption by both Pt NPs and BiOBr NFs, lower recombination rate of photo-generated electrons and holes attributed to the multiple heterojunction, microstructures for facile light injection and adsorption as well as efficient mass transport, and larger specific surface area for enhancing light absorption, increasing the effective contact area between the absorbed dye molecules and catalyst and benefiting the molecule transport of reactants or products.

Observation analysis on characteristics of formation,evolution and transition of a long-lasting severe fog and haze episode in North China

An unusual fog and haze event lasted for one week took place during 1–7 December,2011 over North China.To investigate the characteristics and mechanism of formation,evolution,and transition of the fog and haze event,we studied the microphysical properties such as aerosol,cloud condensation nuclei(CCN),fog droplet spectrum and liquid water content(LWC),as well as horizontal visibility and boundary layer properties,using the data collected in the Project of Low-Visibility Weather Monitoring and Forecasting in the Beijing-Tianjin region.The results indicate that the long-lasting fog and haze event occurred in a high pressure weather system and calm wind condition.The stable boundary-layer structure resulted from temperature inversions that were built by warm advection and radiation cooling provided a favorable condition for the accumulation of polluted aerosols and the formation and development of the fog and haze event.In particular,the continuous southerly wet flow advection made the process a persistent and long-lasting event.The horizontal visibility was almost below 2 km in the whole process,and the lowest visibility was only 56 m.The average LWC was about 10-3 g m-3,and the maximum LWC reached 0.16 g m-3.The aerosol number concentration was more than 10000 cm-3,and its mass concentration ranged from 50 to 160 -g m-3.The further study shows that the fog and haze event experienced three main processes in different intensities during the whole period,each process could be divided into three main stages:aerosol accumulation,transition and mixture of aerosol and fog,and dissipation.Each stage had different physical features:the aerosol accumulation stage was characterized by the increase of aerosol number concentration in Aitken nuclei and accumulation mode sequentially.In the transition and mixing stage of fog and haze,the latent heating produced by fog droplet condensation process and high aerosol number concentration condition intensified the Brownian coagulation process,which induced the small size of aerosols to become larger ones and enhanced the CCN activation process,thereby promoting the explosive development of the fog event.The ratio of aerosol activated to CCN reached 17%,and the ratio of CCN converted to fog droplet exceeded 100%,showing an explosively broadening of fog droplet spectrum.The decrease and dissipation of the fog was caused by an increased solar radiation heating or the passage of cold frontal system.

BiVO_4 semiconductor sensitized solar cells

Semiconductor sensitized solar cells(SSSCs) are promising candidates for the third generation of cost-effective photovoltaic solar cells and it is important to develop a group of robust, environment-friendly and visible-light-responsive semiconductor sensitizers. In this paper, we first synthesized bismuth vanadate(Bi VO4) quantum dots by employing facile successive ionic layer adsorption and reaction(SILAR) deposition technique, which we then used as a sensitizer for solar energy conversion. The preliminary optimised oxide SSSC showed an efficiency of 0.36%, nearly 2 orders of magnitude enhancement compared with bare Ti O2, due to the narrow bandgap absorption of Bi VO4 quantum dots and intimate contact with the oxide substrate. This result not only demonstrates a simple method to prepare Bi VO4 quantum dots based solar cells, but also provides important insights into the low bandgap oxide SSSCs.

Daily shoaling patterns in the zebrafish Danio rerio

Shoaling intensity in zebrafish Danio rerio is believed to vary throughout subjective day and night hours. This experiment examines long term variations in shoaling behavior. Adult zebrafish Dan io rerio were maintained under a 12：12 LD cycle （with dim red light serving as reduced visibility during subjective dark hours）, and their shoaling behavior was monitored every hour for a three-day period of time. Our results show that zebrafish perform shoaling behavior throughout subjective day and under reduced visibility conditions, although mean shoaling times during the light phase were significantly higher than mean shoaling times during the dark phase. However, on the 3^rd day of the experiment, mean shoaling times during the subjective night had increased and mean shoaling times during the subjective day had decreased. This shift in intensity was not seen on the first two days of the study, and may represent the influence of experience on the behavior of the test fish. We believe this study shows that shoaling behavior changes with light/dark cycles and that fish shoal even during reduced visibility conditions.