Fabrication and photocatalytic property of α-Bi2O3 nanoparticles by femtosecond laser ablation in liquid

Fabrication of mesh-like bismuth oxide single crystalline nanoflakes and their visible light photocatalytic activity

“…Zhou et al fabricated ␦-Bi 2 O 3 hierarchical nanostructures assembled by nanosheets through a template-free aqueous method [23]. ␣-Bi 2 O 3 nanoparticles have been produced by femtosecond laser ablation in ethanol at room temperature [24]. However, it is still a challenge to selectively fabricate pure bismuth oxide in specific crystalline phase through a facile soft-chemical way.…”

“…The resultant oxide powders generally showed very fine crystallite size and aggregated to form mesopores or nanopores [25][26][27][28][29][30][31]. Recently, our group has developed an amino acid modified oxalate precursor way to fabricate mesoporous CeO 2 , Mn 2 O 3 , and MnO 2 with hierarchical nanoarchitecture [22][23][24][25][26][27][28][29][30][31][32][33][34]. The effect of amino acids on the formation of hierarchical structure of mesoporous CeO 2 and MnO 2 was examined.…”

Photocatalytic activity of enlarged microrods of α-Bi2O3 produced using ethylenediamine-solvent

“…The formation of isatin sulfonic acid and 2-amine-5-sulfo-benzoic acid, products of the breaking of the indigoid group (NHC ¼CNH) of the IC dye by using α-Bi 2 O 3 microrods suggests that the dye was degraded via oxidation by the presence of the superoxide (O 2 À ) radicals, as has been extensively established by several authors [7,8]. It means that the photogenerated electrons on α-Bi 2 O 3 microrods can be captured by dissolved O 2 to generate O 2 À radicals, suggesting that the conduction band of the α-Bi 2 O 3 microrods must be more negative than that of the couple O 2 /O 2 À ( À0.15 V) [57][58][59].…”

“…After 30 min in dark, this absorbance was slightly decreased (20%), indicating that IC dye in the solution was adsorbed on the α-Bi 2 O 3 microrod surface [6]. Afterwards, during 1 h of the UV irradiation, the decrease of the absorbance peak of IC dye suggests that it was degraded; however, one absorbance peak at 218 nm was raised and the emergence of an isosbestic point at 251 nm indicates that secondary products were formed, which have been extensively identified as Isatin sulfonic acid and 2-amine-5-sulfo-benzoic acid [7][8][9]. The decrease of the absorbance at 610 nm is caused by the breaking of the indigoid group (NHC ¼CNH) causing the IC dye degradation.…”

“…Therefore, preparing α-Bi 2 O 3 semiconductor with reduced grain size would increase its photocatalytic activity making it a promising photocatalyst in future research. Different nanostructures (nanoparticles, nanorods or nanowires) of α-Bi 2 O 3 have been prepared by different methods like: femtosecond pulsed laser ablation in liquids [7], simple one pot sol-gel method [4], free sonochemical process [8], via a catalysts-driven vapor transport method [9], by using g-C 3 N 4 as a template [10] and so on. Specifically, α-Bi 2 O 3 microrods, sometimes mistakenly called as nanorods, have been obtained by a microwave method [11,12] and by a simple chemical precipitation method using inorganic precipitating agents (NaOH, KOH, NH 4 OH) [13][14][15][16][17][18][19], but in most of these cases, the microrods are thermally treated at temperatures about 450-550°C.…”