Multifunctional TiO2 Nanotube-Matrix Composites with Enhanced Photocatalysis and Lithium-Ion Storage Performances

As a multifunctional material, TiO2 shows excellent performance in catalytic degradation and lithium-ion storage. However, high electron-hole pair recombination, poor conductivity, and low theoretical capacity severely limit the practical application of TiO2. Herein, TiO2 nanotube (TiO2 NT) with a novel double-layer honeycomb structure were prepared by two-step electrochemical anodization. Honeycombed TiO2 NT arrays possess clean top surfaces and a long-range ordering, which greatly facilitates the preparation of high-performance binary and ternary materials. A binary TiO2 nanotube@Au nanoparticle (TiO2 NT@Au NP) composite accompanied by appropriately concentrated and uniformly distributed gold particles was prepared in this work. Interestingly, the TiO2 nanotube@Au nanoparticle (TiO2 NT@Au NP) composites not only showed the excellent catalytic degradation effect of methylene blue, but also demonstrated large lithium-ion storage capacity (310.6 μAh cm-2, 1.6 times of pristine TiO2 NT). Based on the realization of the controllable fabrication of binary TiO2 nanotube@MoS2 nanosheet (TiO2 NT@MoS2 NS) composite, ternary TiO2 nanotube@MoS2 nanosheet@Au nanoparticle (TiO2 NT@MoS2 NS@Au NP) composite with abundant defects and highly ordered structure was also innovatively designed and fabricated. As expected, the TiO2 NT@MoS2 NS@Au NP anode exhibits extremely high initial discharge specific capacity (487.4 μAh cm-2, 2.6 times of pristine TiO2 NT) and excellent capacity retention (81.0%).