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Acetic Anhydride as an Oxygen Donor in the Non‐Hydrolytic Sol–Gel Synthesis of Mesoporous TiO 2 with High Electrochemical Lithium Storage Performances
Author(s) -
Wang Yanhui,
Kim Sanghoon,
Louvain Nicolas,
Alauzun Johan G.,
Mutin P. Hubert
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201806073
Subject(s) - mesoporous material , calcination , anatase , specific surface area , materials science , lithium (medication) , chemical engineering , titanium , acetic anhydride , catalysis , inorganic chemistry , chemistry , organic chemistry , photocatalysis , medicine , engineering , metallurgy , endocrinology
An original, halide‐free non‐hydrolytic sol–gel route to mesoporous anatase TiO 2 with hierarchical porosity and high specific surface area is reported. This route is based on the reaction at 200 °C of titanium(IV) isopropoxide with acetic anhydride, in the absence of a catalyst or solvent. NMR spectroscopic studies indicate that this method provides an efficient, truly non‐hydrolytic and aprotic route to TiO 2 . Formation of the oxide involves successive acetoxylation and condensation reactions, both with ester elimination. The resulting TiO 2 materials were nanocrystalline, even before calcination. Small (about 10 nm) anatase nanocrystals spontaneously aggregated to form mesoporous micron‐sized particles with high specific surface area (240 m 2 g −1 before calcination). Evaluation of the lithium storage performances shows a high reversible specific capacity, particularly for the non‐calcined sample with the highest specific surface area favouring pseudo‐capacitive storage: 253 mAh g −1 at 0.1 C and 218 mAh g −1 at 1 C (C=336 mA g −1 ). This sample also shows good cyclability (92 % retention after 200 cycles at 336 mA g −1 ) with a high coulombic efficiency (99.8 %). Synthesis in the presence of a solvent (toluene or squalane) offers the possibility to tune the morphology and texture of the TiO 2 nanomaterials.