Applied Surface Science, Vol.462, 285-290, 2018
Shell of black titania prepared by sputtering TiO2 target in H-2 + Ar plasma
Black titania films that resemble the shell of recently reported black TiO2, were deposited by DC sputtering a conductive TiO2 target in a hydrogen-containing plasma. Synchrotron radiation was used for identifying the phases present in the samples. Anatase-defective rutile transformation, with further amorphization and transformation into intermediate Ti oxides were observed. Samples became black and conductive at the stage of transformation into defective rutile and the amorphous sample showed flat absorbance in the visible region. The amount of O-H groups on the film surface reaches 80% with increasing hydrogen in the plasma. Nevertheless, the black samples are inferior photocatalytically to transparent titania. Based on the results, some new insights into the phenomenon of black TiO2 are provided.
Keywords:Black titania;Hydrogenation;Magnetron sputtering;Synchrotron measurements;TiO2;Photocatalysis