Controllable morphology of Bi 2 S 3 nanostructures formed via hydrothermal vulcanization of Bi 2 O 3 thin-film layer and their photoelectrocatalytic performances

Abstract Bi 2 S 3 nanostructures with various morphologies were synthesized through hydrothermal vulcanization at different sulfur precursor (thiourea) concentrations. A 100 nm thick sputter-deposited Bi 2 O 3 thin-film layer on a fluorine-doped tin oxide glass substrate was used as a sacrificial template layer. The etching of the Bi 2 O 3 sacrificial template layer and the regrowth of Bi 2 S 3 crystallites during hydrothermal vulcanization produced the different Bi 2 S 3 nanostructure morphologies. The lowest sulfur precursor concentration (0.01 M) induced the formation of Bi 2 S 3 nanosheets, whereas the Bi 2 S 3 nanoribbons and nanowires were formed with increased sulfur precursor concentrations of 0.03 and 0.1 M, respectively. These results indicate that sputter-deposited Bi 2 O 3 thin-film layers can be effectively used to form low-dimensional Bi 2 S 3 crystals with controllable morphologies. Among the various Bi 2 S 3 samples, the Bi 2 S 3 nanosheets exhibited superior photoactive ability. The higher active surface area, surface defect density, light absorption capacity, and photo-induced charge separation ability of Bi 2 S 3 nanosheets explain their superior photoelectrocatalytic degradation ability of rhodamine B dyes.