Arsenic trapping by iron oxyhydroxides and carbonates at hydrothermal spring outlets

Well Crystallized α‐GaOOH Nanocrystals Synthesized through Hydrothermal Routes and Their Properties

“…Under high temperature, the Ga(OH) 3 gelatinous precipitates were transformed to GaOOH precipitates. The pH value of the system was thus kept at a certain level, which drove the reaction to carry out.…”

“…In a typical synthesis, 0.5 g of Ga(NO 3 ) 3 •H 2 O was dissolved in 5 mL of distilled water and its pH value was about 3. 0.75 g of NaN 3 was also dissolved in 5 mL of distilled water and its pH value was about 9.…”

“…0.75 g of NaN 3 was also dissolved in 5 mL of distilled water and its pH value was about 9. The two solutions were mixed and added to a Teflon-lined autoclave of 30 mL capacity.…”

“…2 The complementary laboratory and field experimental approaches have shown that Fe oxyhydroxides play an important role in the adsorption and desorption of As in water. 3 ErOOH-based nanomaterials such as nanorods and nanofibres are shown to exhibit strong fluorescence bands in the blue-green spectral region. 4 However, up to date, few attempts have been devoted to the synthesis of metal oxyhydroxide nanoparticles, compared with metal oxides.…”

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A facile hydrothermal process involving Ga(NO 3 ) 3 •H 2 O•NaN 3 solutions led to the formation of α-GaOOH nano-platelets. X-ray diffraction (XRD) pattern revealed that the synthesized samples belonged to an orthorhombic crystal structure with lattice constants a＝0.4510 nm, b＝0.9750 nm and c＝0.2965 nm.

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