A TiO2 nanorod template was successfully decorated with a copper oxide layer with various crystallographic phases using sputtering and postannealing procedures. The crystallographic phase of the layer attached to the TiO2 was adjusted from a single Cu2O phase or dual Cu2O–CuO phase to a single CuO phase by changing the postannealing temperature from 200 °C to 400 °C. The decoration of the TiO2 (TC) with a copper oxide layer improved the light absorption and photoinduced charge separation abilities. These factors resulted in the composite nanorods demonstrating enhanced photoactivity compared to that of the pristine TiO2. The ternary phase composition of TC350 allowed it to achieve superior photoactive performance compared to the other composite nanorods. The possible Z-scheme carrier movement mechanism and the larger granular size of the attached layer of TC350 under irradiation accounted for the superior photocatalytic activity in the degradation of RhB dyes.

Bi2S3 nanostructures with various morphologies were synthesized through hydrothermal vulcanization at different sulfur precursor (thiourea) concentrations. A 100 nm thick sputter-deposited Bi2O3 thin-film layer on a fluorine-doped tin oxide glass substrate was used as a sacrificial template layer. The etching of the Bi2O3 sacrificial template layer and the regrowth of Bi2S3 crystallites during hydrothermal vulcanization produced the different Bi2S3 nanostructure morphologies. The lowest sulfur precursor concentration (0.01 M) induced the formation of Bi2S3 nanosheets, whereas the Bi2S3 nanoribbons and nanowires were formed with increased sulfur precursor concentrations of 0.03 and 0.1 M, respectively. These results indicate that sputter-deposited Bi2O3 thin-film layers can be effectively used to form low-dimensional Bi2S3 crystals with controllable morphologies. Among the various Bi2S3 samples, the Bi2S3 nanosheets exhibited superior photoactive ability. The higher active surface area, surface defect density, light absorption capacity, and photo-induced charge separation ability of Bi2S3 nanosheets explain their superior photoelectrocatalytic degradation ability of rhodamine B dyes.

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