Aqueous dispersed ablated bismuth species and their potential as colloidal Bi precursors in synthetic strategies

Abstract

Intense scientific efforts have been focused on the exploration of the unusual physical and chemical properties of colloidal nanoparticles (NPs). Here, surfactant-free ablated bismuth colloidal species showing distinctive advantages of high reactivity and reducibility were generated by laser-ablating metal Bi in deionized water. They can further react with water molecules and display self-assembly behaviour to form Bi(OH)₃ nanowires at ambient condition. Interestingly, under aging at 60 °C or light irradiation, Bi-based colloids will tend to react and self-assemble into phases of Bi₂O₃ and Bi₂O₄ nanocrystals. Furthermore, various bismuth-containing compounds, such as bismuth oxyhalides (BiOX, X = Cl, Br, I), Ag/Au/Pt-modified BiOCl, BiVO₄, and Bi₂WO₆ semiconductors were also successfully produced through the reaction of ablated bismuth colloidal species with corresponding chemical reagents or with ablated V and W colloidal species. These synthetic strategies proved that LAL-induced colloidal species are capable of serving as unique chemical precursors. The relatively slow, dynamic species-by-species reaction greatly favours controllable growth and tunable nanostructure compared with the conventional rapid ion-by-ion reaction. Importantly, this growth route provides more underlying insights regarding the growth and assembly mechanisms of nanocrystals without influence from additional chemical ions or surfactants.