Turning Bulk Titanium into Rutile Nanorods in One Step: Synthesis, Mechanism, and Application

A one-step method is introduced for synthesizing rutile TiO2 nanorods (TNRs) directly from Ti metal. TNRs are generated by hydrothermally processing a Ti metal disc in H2SO4/CuSO4 solutions at 150 degrees C. In a 112-day long experiment, different ledgewise growth mechanisms are observed in the early (7-day) and the late (112-day) stages of TNR formation. A unique phenomenon is observed in that the length of the TNRs is a function of processing time and the H2SO4/CuSO4 concentration, whereas the diameter of the TNRs is almost unaffected. It is found that the diameter of these nanorods can only be affected by variation of temperature. A mechanism involving the critical dimension of the (101) growth front is proposed in this paper. In addition, methyl orange degradation efficiency of 90% was achieved when the fabricated TNRs were used as immobilized photocatalysts.