Rapid microwave hydrothermal synthesis of GaOOH nanorods with photocatalytic activity toward aromatic compounds

Abstract

GaOOH nanorods were synthesized from Ga(NO(3))(3) via a facile microwave hydrothermal method. The obtained sample was characterized by x-ray diffraction, N(2) sorption-desorption, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, electron spin resonance, and x-ray photoelectron spectroscopy. The results revealed that the as-synthesized sample was consisted of rod-like particles. It possessed a surface area of 14.3 m(2) g(-1), and a band gap of 4.75 eV. The photocatalytic property of GaOOH nanorods was evaluated by the degradation of aromatic compounds (such as benzene and toluene) in an O(2) gas stream under ultraviolet (UV) light illumination. The results demonstrated that GaOOH nanorods exhibited superior photocatalytic activity and stability as compared to commercial TiO(2) (P25, Degussa Co.) in both benzene and toluene degradation. In the extended (35 h) reaction test toward benzene, GaOOH maintained a high activity, and no obvious deactivation was observed. A possible mechanism of the photocatalysis over GaOOH is proposed.

Synthesis and optical characterization of mixed nanostructured aluminum–gallium oxy-hydroxide

“…TEM was used to image the morphology of the hypothesized Al 0.5 Ga 0.5 OOH material (Figure 1(b)). The materials are observed to conform to rod-like morphologies, as expected from previous reports [12,13].…”

“…In this study, aluminum nitrate nonahydrate and gallium nitrate hydrate precursors dissolved at various concentrations in DI water were titrated with sodium hydroxide and a previously reported hydrothermal microwave synthesis (GaOOH) was performed [12]. This titration and hydrothermal reaction has been done with AlOOH using an autoclave in previous work [13].…”

“…Blue shifting is seen from the high Ga concentration samples to the equal concentration samples and wavelength differences become negligible between peaks with added Al concentration. The band gap difference between AlOOH (4.51 eV) [14] and GaOOH (4.75 eV) [12] would suggest a red shift; however, the effects of size at nanometer scales must be accounted for. In this study, it is evident that size effects overcome the material bandgap considerations.…”

Degradation mechanism of hydrogen-terminated porous silicon in the presence and in the absence of light

“…It is well known that the ·OH radicals could generate in conduction and valance bands. 12,19 To confirm the generated positions of the ·OH radicals in H-PSi wafers, ·O 2 − radicals were analyzed. Fig.…”

“…The ·OH radicals can be formed when H 2 O 2 molecules capture an electron. 12,13,19 Based on such a realization, the schematic diagram of the reaction in the conduction band of porous Si is shown in Fig. 6.…”