The
stratified nature of LiCoO2 (LCO) makes such materials
suitable for rechargeable Li-ion batteries. The existing synthesis
technology for LCO, however, results in a low surface area, low activity,
and a limited density of active sites, which limit its applications
in catalysis, in which the material’s functionality is determined
by the reactions that occur on its surface. The present work reports
a simplified and high-yield strategy for using bulk LCO in multifunctional
two-dimensional (2D) catalysts. The recovery involves ordered and/or
disordered leaching of Li+ as a result of H+ intercalation and formation of catalytically active oxygen vacancies
at high concentrations (∼32 atom %). This is followed by exfoliation
of the LCO into porous nanosheets through intercalation of tetramethylammonium
hydroxide. The catalytic performance of the etched and exfoliated
LCOs was investigated; the 1 M HCl-etched LCO exhibited the highest
photocatalytic dye degradation (99.9%) under simulated solar light,
while the etched and fully exfoliated LCO showed outstanding CO oxidation,
with a T
90% = 140 °C, which is significantly
lower than that of the bulk LCO catalyst (T
90% = 360 °C).