Rapid flame synthesis of internal Mo⁶⁺ doped TiO₂ nanocrystals in situ decorated with highly dispersed MoO₃ clusters for lithium ion storage

Abstract

The rational design of nanoheterostructured materials has attracted much attention because of its importance for developing highly efficient LIBs. Herein, we have demonstrated that internal Mo(6+) doped TiO2 nanocrystals in situ decorated with highly dispersed MoO3 clusters have been realized by a facile and rapid flame spray pyrolysis route for electrochemical energy storage. In such intriguing nanostructures, internal Mo(6+) doping can improve the conductivity of electrode materials and facilitate rapid Li(+) intercalation and ion transport and the heteroassembly of highly dispersed ultrafine MoO3 clusters with excellent electrochemical activity endows the TiO2 with extra Li(+) ion storage ability as well as incorporates Mo(6+). Thus, the as-prepared nanohybrid electrodes exhibit a high specific capacity and superior rate capability due to the maximum synergetic effect of TiO2, Mo(6+) and ultrafine MoO3 clusters. Moreover, the aerosol flame process with a unique temperature gradient opens a new strategy to design novel hybrid materials by the simultaneous doping and heteroassembly engineering for next-generation LIBs.

Simultaneous Control over Lattice Doping and Nanocluster Modification of a Hybrid CuOx/TiO2 Photocatalyst during Flame Synthesis for Enhancing Hydrogen Evolution

“…In order to induce visible light activity into normally purely UV‐active TiO 2 , thus enabling its activation for photocatalytic processes also by visible light, a number of TiO 2 ‐based hybridization strategies were proposed, especially transition metal doping . The effect of doping on the activity depends on many factors, for example, the method of doping, and the type and the concentration of dopant .…”

Self‐Assembly Approach for Synthesis of Nanotubular Molybdenum Trioxide/Titania Composite Anode for Lithium‐Ion Batteries

“…For the Ti 2p region (Figure b), the peaks of Ti 2p 3/2 and Ti 2p 1/2 are present at 458.7 and 464.5 eV, respectively, and the 5.8 eV peak separation of which reveals that the titanium(IV) atoms are bonded stoichiometrically to oxygen atoms . As displayed by Figure c, the peak centered at 530.44 eV is assigned to the lattice oxygen of Mo−O and Ti−O bonds in molybdenum trioxide and titania, respectively; and the peaks at 531.83 and 533.28 eV are attributed to the surface hydroxyl group of Ti−OH and the chemisorbed water molecules, respectively . These results confirm that the MoO 3 /TiO 2 composite is formed, which agrees well with the HR‐TEM results discussed above.…”

“…These results confirm that the MoO 3 /TiO 2 composite is formed, which agrees well with the HR‐TEM results discussed above. Compared with the O 1s spectrum of the control sample of MoO 3 flakes (Figure S7 in the Supporting Information), the peak of lattice oxygen (530.44 eV) observed in the MoO 3 ‐76 %‐TiO 2 composite showed a negative shift of 0.26 eV in the binding energy, which was caused by electron transport from Ti 4+ to Mo 6+ due to the stronger electronegativity of molybdenum than that of titanium …”

“…200 mAh g −1 cycled at 100 mA g −1 until the 20th cycle) . The discharge capacity of the MoO 3 ‐76 %‐TiO 2 composite was 374.9 mAh g −1 at a higher current density of 500 mA g −1 (as shown below), which was slightly higher than that of the Mo 6+ ‐doped‐TiO 2 /MoO 3 nanocomposite prepared by a rapid flame‐spray pyrolysis route (365.9 mAh g −1 ) . It is clear that the present nanotubular MoO 3 /TiO 2 composite exhibits excellent electrochemical performances.…”

Preparation and electrochemical properties of graphene‐supported Si‐TiO2 nanospheres as anode material for Li‐ion batteries

“…But its lower electrical conductivity limits its further application in the large‐scale energy storage fields. It has been found that the compounds formed by coating or doping with additives in TiO 2 could effectively improve the electrochemical performance of TiO 2 , such as Fe 3 O 4 /TiO 2 hollow spheres, Ag or Au nanoparticle‐embedded TiO 2 nanofibers, Zn‐doped mesoporous TiO 2 , Sn‐doped carbon‐coated TiO 2 spheres, and Mo 6+ ‐doped TiO 2 . Among these additives, content of the silicon in nature is abundant, and its theoretical capacity attains 4200 mAh/g.…”