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We demonstrate the use of elemental precursors Cu, Fe, Sn, and S to obtain a mawsonite (Cu6Fe2SnS8)/stannite (Cu2FeSnS4) composite using a solid-state process at ambient temperature in an industrial eccentric vibration mill for up to 240 min in argon atmosphere. The samples were characterized using various analytical techniques such as x-ray diffractometry, scanning electron microscopy, energy-dispersive x-ray spectroscopy, and nitrogen adsorption and magnetic measurements. For thermoelectric measurements, the properties of samples densified via spark plasma sintering were measured using standard methods needed to calculate the figure of merit. The transformation of elemental precursors to a composite mixture proceeds relatively rapidly via several intermediate steps. The kinetics of this transformation is also in good agreement with the results for the unconsumed sulfur content in the reaction mixtures and can also be correlated with the magnetization results. Based on the thermoelectric measurements of the sample milled for 240 min, the calculated figure of merit reached a value of zT = 0.51 at 623 K due to a very low lattice thermal conductivity of 0.29 W/m-K and moderate power factor of 3.3 μW/cm-K2. The thermoelectric results obtained for the material are comparable to previously published values for pure mawsonite prepared from elements by laboratory ball milling. [ABSTRACT FROM AUTHOR]

TiO2/g-C3N4/MoS2 nanocomposite photocatalysts were synthesized via two-steps in situ solvothermal method. The nanocomposites exhibit an extended visible-light photoresponse, higher efficiency of charge carriers separation, and improved photocatalytic degradation of methylene blue (MB). TiO2/g-C3N4/MoS2 nanoparticles enjoys much higher degradation ratio (95%) under visible light illumination for 30 min than P25 (63%), TiO2/g-C3N4 (45%) and TiO2 (26%). The heterojunctions of TiO2/g-C3N4 and TiO2/MoS2 play a main role in the enhanced photocatalytic performance. The electrons generated in MoS2 and g-C3N4 under visible light migrate to the conduction band of TiO2 to degrade MB dye. The heterojunctions can enhance the separation of photogenerated electron-hole pairs and improve the utilization of photons. This work demonstrates that synergetic effect of g-C3N4 and MoS2, which is a good choice to improve the utilization of visible light of TiO2-based materials. [ABSTRACT FROM AUTHOR]

Pinus is an economically and ecologically important genus whose members are dominant components globally in low-latitude mountainous and mid-latitude temperate forests. Pinus species richness is currently concentrated in subtropical mid-low latitudes of the Northern Hemisphere, differing from the latitudinal diversity gradient mostly recognized in woody angiosperms. How the present pattern was developing in Earth's past is still poorly studied, particularly in eastern Asia. Here, a new fossil species, Pinus shengxianica sp. nov. is described based on a fossil seed cone from the Late Miocene Shengxian Formation in Zhejiang, southeast China. A co-occurring cone is recognized as a known fossil species, Pinus speciosa Li. Extensive comparison of extant and fossil members of Pinus suggests P. shengxianica shares a striking cone similarity to Pinus merkusii and Pinus latteri (subsection Pinus ) from tropical Southeast Asia in having annular bulges around the umbo on the apophysis. The morphological resemblance indicates these two extant low-latitude pines probably possess a close affinity with the present newly-discovered P. shengxianica and originated from East Asian mid-low latitude ancestors during this generic re-diversification in the Miocene. This scenario is consistent with the evolutionary trajectory reflected by the pine fossil history and molecular data, marking the Miocene as a key period for the origin and evolution of most extant pines globally. The co-occurrences of diverse conifers and broadleaved angiosperms preferring diverse niches demonstrate Late Miocene eastern Zhejiang was one of the hot spots for coniferophyte diversity and hosted a needled-broadleaved mixed forest with complex vegetation structure and an altitudinal zonation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)