Influence of MnO_(x)deposition on TiO_(2)nanotube arrays for electrooxidation

TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnO_(x))was composited with TiO_(2)nanotube arrays(TiO_(2)NTAs)that in-situ oxidized on porous Ti sponge,forming the MnO_(x)-TiO_(2)NTAs anode.XANES and XPS analysis further proved that the composition of MnO_(x)is Mn2O3.Electrochemical characterizations revealed that increasing the composited concentration of MnO_(x)can improve the conductivity and reduce oxygen evolution potential so as to improve the electrochemical activity of the composited MnO_(x)-TiO_(2)NTAs anode.Meanwhile,the optimal degradation rate of benzoic acid(BA)was achieved using MnO_(x)-TiO_(2)NTAs with a MnO_(x)concentration of 0.1 mmol L^(-1),and the role of MnO_(x)was proposed based on DFT calculation.Additionally,the required electrical energy(EE/O)to destroy BA was optimized by varying the composited concentration of MnO_(x)and the degradation voltage.These quantitative results are of great significance for the design and application of high-performance materials for EAOPs.

Degradation of 2,4,6-trichlorphenol by producing hydrogen using ultrasonic mist generated from photocatalysts suspension

Photocatalytic hydrogen production synergized with the oxidation of pollutants is an environmentally friendly and economical approach to generate clean energy and remove the pollution from environment.In this study,photocatalytic hydrogen production cooperating with 2,4,6-trichlorophenol(2,4,6-TCP)degradation have been reinforced by introducing an ultrasonic atomization.The degradation of 2,4,6-TCP in a mist of three photocatalysts(g-C3N4,TiO2,and Bi2O3)generated by ultrasonic atomization was performed under 254 nm ultraviolet(UV254)light irradiation.The results showed that,under UV254 irradiation,three different photocatalysts(g-C3N4,TiO2,and Bi2O3)all accelerated both hydrogen production and 2,4,6-TCP degradation.Additionally,2,4,6-TCP degradation and photocatalytic hydrogen production exhibited an obvious synergistic effect,since 2,4,6-TCP has a strong tendency to react with photo-generated holes and their second radicals so as to inhibit the recombination of carriers,and thus improved the efficiency of hydrogen production simultaneously.Moreover,by introducing ultrasonic atomization,the atomized droplets acted as micro-photocatalytic units to replace the macrophotocatalytic reaction reactor.Therefore,the mass transfer distance for free radicals was restricted and the utilization of light energy by photocatalysts was increased.Further,the reaction efficiency was improved.The results reveal environmentally friendly and economical potential of hydrogen production by photocatalytic degradation of 2,4,6-TCP in atomized droplets.

Global brown carbon emissions from combustion sources

Light-absorbing organic carbon(OC),sometimes known as Brown Carbon(BrC),has been recognized as an important fraction of carbonaceous aerosols substantially affecting radiative forcing.This study firstly developed a bottom-up estimate of global primary BrC,and discussed its spatiotemporal distribution and source contributions from 1960 to 2010.The global total primary BrC emission from both natural and anthropogenic sources in 2010 was 7.26(5.98-8.93 as an interquartile range)Tg,with 43.5%from anthropogenic sources.High primary BrC emissions were in regions such as Africa,South America,South and East Asia with natural sources(wild fires and deforestation)contributing over 70%in the former two regions,while in East Asia,anthropogenic sources,especially residential solid fuel combustion,accounted for over 80%of the regional total BrC emissions.Globally,the historical trend was mainly driven by anthropogenic sources,which increased from 1960 to 1990 and then started to decline.Residential emissions significantly impacted on emissions and temporal trends that varied by region.In South and Southeast Asia,the emissions increased obviously due to population growth and a slow transition from solid fuels to clean modern energies in the residential sector.It is estimated that in primary OC,the global average was about 20%BrC,but this ratio varied from 13%to 47%,depending on sector and region.In areas with high residential solid fuel combustion emissions,the ratio was generally twice the value in other areas.Uncertainties in the work are associated with the concept of BrC and measurement technologies,pointing to the need for more studies on BrC analysis and quantification in both emissions and the air.

Rare bilateral C3 cervical spondylolysis: Report of four cases and a literature review

Objective: To review and discuss the etiology, diagnosis and treatment C3 of bilateral cervical spondylolysis. Methods: This was a retrospective review of the clinical features, imaginge findings,and treatment of 4 cases of bilateral C3 cervical spondylolysis, with a review of the literature. Results: A 21‐year‐old woman, a 26‐year‐old man, a 14‐year‐old boy, and a 46‐year‐old man were diagnosed with bilateral C3 cervical spondylolysis. The patients had characteristic bilateral clefts between the articular pillar and the facets of C3, as well as spina bifida on CT. Although spondylolisthesis was not observed, spinal cord compression was definitive. All patients underwent posterior decompression with satisfactory results. Conclusions: C3 cervical spondylolysis is rare condition. The cause is most likely congenital. Diagnosis is dependent on characteristic radiological features. Surgical treatment is the first choice.