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A facile one-pot microwave assisted solvothermal synthesis using various ratios of ethylene glycol (EG) and ethanol was developed to synthesize flower-like BiOBr microspheres. Such synthesized microspheres were characterized using X-ray photoelectron spectroscopy, X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, the Brunauer-Emmett-Teller surface area, and UV-Visible diffuse reflectance spectra. Flower-like BiOBr microspheres were composed of loosely packed nanoplates which are interconnected to each other. Experimental results suggested that ethanol played a crucial role in directing the construction of microspheres without any misorientations. The photocatalytic activity of BiOBr microspheres was tested using the photodegradation of tartaric acid irradiated with visible light and compared with solvothermally synthesized BiOBr microspheres and commercial BiO. BiOBr microspheres synthesized using the solvent mixture containing EG and ethanol at the ratio of 3:1 could degrade 98 % tartaric acid in 240 min with visible light (λ ≥ 400 nm) due to the synergistic effect of favorable microstructure with high surface area and suitable band gap of 2.92 eV. Since the resulting BiOBr microspheres are reusable without any loss in photocatalytic activity and more stable without any change in their morphology, it holds as a very promising photocatalysts for the treatment of organic pollutants. [ABSTRACT FROM AUTHOR]

Methane is one of the promising alternatives of petroleum, which should be used for not only a fuel but also a resource for hydrogen and more useful chemicals as with the petroleum. However, the selective methane conversion to them is still difficult in contrast to the combustion. Three types of photocatalytic reactions for methane conversion, i.e., the photocatalytic non-oxidative coupling of methane (2CH → CH + H), the photocatalytic dry reforming of methane (CH + CO → 2CO + 2H) and the photocatalytic steam reforming of methane (CH + 2HO → 4H + CO), can take place around room temperature or at a mild condition such as 473 K using photoenergy and semiconductor photocatalyst. In the present short review, the details of each photocatalytic reaction and the design concept of the semiconductor photocatalysts for each photocatalytic methane conversion were summarized and discussed. [ABSTRACT FROM AUTHOR]

The article presents abstracts of several studies on environmental geochemistry. Some of the abstracts presented include "Biogeochemical Cycling of Nutrients in Karstic Catchments, Southwestern China: Linkages to Changes of Eco-Environments," by Congqiang Liu and "Emerging Organic Contamination in China," by Guibin Jiang and colleagues.