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%).